ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • American Physical Society  (110,818)
  • Cambridge University Press  (30,205)
  • Annual Reviews
  • 2020-2023  (22)
  • 1995-1999  (76,919)
  • 1980-1984  (39,464)
  • 1975-1979  (35,139)
  • 1940-1944  (2,811)
Collection
Years
Year
  • 1
    facet.materialart.
    Unknown
    Cambridge University Press
    In:  EPIC3Antarctic Science, Cambridge University Press, 33(6), pp. 575-595, ISSN: 0954-1020
    Publication Date: 2022-01-13
    Description: The waters along the West Antarctic Peninsula (WAP) have experienced warming and increased freshwater inputs from melting sea ice and glaciers in recent decades. Challenges exist in understanding the consequences of these changes on the inorganic carbon system in this ecologically important and highly productive ecosystem. Distributions of dissolved inorganic carbon (CT), total alkalinity (AT) and nutrients revealed key physical, biological and biogeochemical controls of the calcium carbonate saturation state (Ωaragonite) in different water masses across the WAP shelf during the summer. Biological production in spring and summer dominated changes in surface water Ωaragonite (ΔΩaragonite up to +1.39; ∼90%) relative to underlying Winter Water. Sea-ice and glacial meltwater constituted a minor source of AT that increased surface water Ωaragonite (ΔΩaragonite up to +0.07; ∼13%). Remineralization of organic matter and an influx of carbon-rich brines led to cross-shelf decreases in Ωaragonite in Winter Water and Circumpolar Deep Water. A strong biological carbon pump over the shelf created Ωaragonite oversaturation in surface waters and suppression of Ωaragonite in subsurface waters. Undersaturation of aragonite occurred at 〈 ∼1000 m. Ongoing changes along the WAP will impact the biologically driven and meltwater-driven processes that influence the vulnerability of shelf waters to calcium carbonate undersaturation in the future.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev , info:eu-repo/semantics/article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2022-06-22
    Description: Pliocene–Quaternary faults are relevant structures with which to constrain the seismotectonic context and contribute to the evaluation of the seismic hazard of a region. Many of these faults, however, do not show clear surface evidence even when releasing earthquakes. For these reasons they can be extremely dangerous as they receive relatively little attention and can be difficult to identify. From among the various surface geology studies and/or palaeoseismological investigations, we focus our attention on the integration of different datasets such as seismic reflection profiles, surface kinematic data and the relocation of seismological data, which make it possible to identify and characterize active faults whose dimension and earthquake potential would otherwise not be large enough to make them identifiable. We take as an example the Montespertoli NE-trending fault in southern Tuscany (central Italy) with which we associate the 2016 M=3.9 Castelfiorentino earthquake. This structure is part of a wider (in the order of 15–20 km) crustal-scale shear zone, which may be responsible for strong historical earthquakes in the area.
    Description: Published
    Description: 853 - 872
    Description: 4T. Sismicità dell'Italia
    Description: JCR Journal
    Keywords: active faults ; seismic faults ; Earthquakes ; strike-slip faults ; inner Northern Apennines ; solid earth
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2022-05-26
    Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Derr, N. J., Fronk, D. C., Weber, C. A., Mahadevan, A., Rycroft, C. H., & Mahadevan, L. Flow-driven branching in a frangible porous medium. Physical Review Letters, 125(15), (2020): 158002, doi:10.1103/PhysRevLett.125.158002.
    Description: Channel formation and branching is widely seen in physical systems where movement of fluid through a porous structure causes the spatiotemporal evolution of the medium. We provide a simple theoretical framework that embodies this feedback mechanism in a multiphase model for flow through a frangible porous medium with a dynamic permeability. Numerical simulations of the model show the emergence of branched networks whose topology is determined by the geometry of external flow forcing. This allows us to delineate the conditions under which splitting and/or coalescing branched network formation is favored, with potential implications for both understanding and controlling branching in soft frangible media.
    Description: N. D. was partially supported by the NSF-Simons Center for Mathematical and Statistical Analysis of Biology at Harvard, Grant No. 1764269, and the Harvard Quantitative Biology Initiative. C. H. R. and N. D. were partially supported by the National Science Foundation under Grant No. DMS-1753203. C. H. R. was partially supported by the Applied Mathematics Program of the U.S. DOE Office of Science Advanced Scientific Computing Research under Contract No. DE-AC02-05CH11231. L. M. was partially supported by the National Science Foundation under Grants No. DMR-2011754 and No. DMR-1922321.
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2022-10-27
    Description: This paper is not subject to U.S. copyright. The definitive version was published in Sherwood, C. R., van Dongeren, A., Doyle, J., Hegermiller, C. A., Hsu, T.-J., Kalra, T. S., Olabarrieta, M., Penko, A. M., Rafati, Y., Roelvink, D., van der Lugt, M., Veeramony, J., & Warner, J. C. Modeling the morphodynamics of coastal responses to extreme events: what shape are we in? Annual Review of Marine Science, 14, (2022): 457–492, https://doi.org/10.1146/annurev-marine-032221-090215.
    Description: This review focuses on recent advances in process-based numerical models of the impact of extreme storms on sandy coasts. Driven by larger-scale models of meteorology and hydrodynamics, these models simulate morphodynamics across the Sallenger storm-impact scale, including swash,collision, overwash, and inundation. Models are becoming both wider (as more processes are added) and deeper (as detailed physics replaces earlier parameterizations). Algorithms for wave-induced flows and sediment transport under shoaling waves are among the recent developments. Community and open-source models have become the norm. Observations of initial conditions (topography, land cover, and sediment characteristics) have become more detailed, and improvements in tropical cyclone and wave models provide forcing (winds, waves, surge, and upland flow) that is better resolved and more accurate, yielding commensurate improvements in model skill. We foresee that future storm-impact models will increasingly resolve individual waves, apply data assimilation, and be used in ensemble modeling modes to predict uncertainties.
    Description: All authors except D.R. were partially supported by the IFMSIP project, funded by US Office of Naval Research grant PE 0601153N under contracts N00014-17-1-2459 (Deltares), N00014-18-1-2785 (University of Delaware), N0001419WX00733 (US Naval Research Laboratory, Monterey), N0001418WX01447 (US Naval Research Laboratory, Stennis Space Center), and N0001418IP00016 (US Geological Survey). C.R.S., C.A.H., T.S.K., and J.C.W. were supported by the US Geological Survey Coastal/Marine Hazards and Resources Program. A.v.D. and M.v.d.L. were supported by the Deltares Strategic Research project Quantifying Flood Hazards and Impacts. M.O. acknowledges support from National Science Foundation project OCE-1554892.
    Keywords: Coastal morphodynamics ; Extreme storms ; Coastal modeling ; Sandy coasts ; Waves ; Sediment transport
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2022-10-26
    Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Hughen, K. A., & Heaton, T. J. Updated Cariaco Basin C-14 calibration dataset from 0-60 cal kyr BP. Radiocarbon, 62(4), (2020): 1001-1043, doi:10.1017/RDC.2020.53.
    Description: We present new updates to the calendar and radiocarbon (14C) chronologies for the Cariaco Basin, Venezuela. Calendar ages were generated by tuning abrupt climate shifts in Cariaco Basin sediments to those in speleothems from Hulu Cave. After the original Cariaco-Hulu calendar age model was published, Hulu Cave δ18O records have been augmented with increased temporal resolution and a greater number of U/Th dates. These updated Hulu Cave records provide increased accuracy as well as precision in the final Cariaco calendar age model. The depth scale for the Ocean Drilling Program Site 1002D sediment core, the primary source of samples for 14C dating, has been corrected to account for missing sediment from a core break, eliminating age-depth anomalies that afflicted the earlier calendar age models. Individual 14C dates for the Cariaco Basin remain unchanged from previous papers, although detailed comparisons of the Cariaco calibration dataset to those from Hulu Cave and Lake Suigetsu suggest that the Cariaco marine reservoir age may have shifted systematically during the past. We describe these recent changes to the Cariaco datasets and provide the data in a comprehensive format that will facilitate use by the community.
    Description: K.A. Hughen was supported by funds from U.S. NSF grant #OCE-1657191, and by the Investment in Science Fund at WHOI. T.J. Heaton is supported by a Leverhulme Trust Fellowship RF-2019-140\9, “Improving the Measurement of Time Using Radiocarbon”.
    Keywords: Calibration ; Climate ; Radiocarbon
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2022-10-26
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Baker, M. G., Aster, R. C., Wiens, D. A., Nyblade, A., Bromirski, P. D., Gerstoft, P., & Stephen, R. A. Teleseismic earthquake wavefields observed on the Ross Ice Shelf. Journal of Glaciology, 67(261), (2021): 58-74, https://doi.org/10.1017/jog.2020.83.
    Description: Observations of teleseismic earthquakes using broadband seismometers on the Ross Ice Shelf (RIS) must contend with environmental and structural processes that do not exist for land-sited seismometers. Important considerations are: (1) a broadband, multi-mode ambient wavefield excited by ocean gravity wave interactions with the ice shelf; (2) body wave reverberations produced by seismic impedance contrasts at the ice/water and water/seafloor interfaces and (3) decoupling of the solid Earth horizontal wavefield by the sub-shelf water column. We analyze seasonal and geographic variations in signal-to-noise ratios for teleseismic P-wave (0.5–2.0 s), S-wave (10–15 s) and surface wave (13–25 s) arrivals relative to the RIS noise field. We use ice and water layer reverberations generated by teleseismic P-waves to accurately estimate the sub-station thicknesses of these layers. We present observations consistent with the theoretically predicted transition of the water column from compressible to incompressible mechanics, relevant for vertically incident solid Earth waves with periods longer than 3 s. Finally, we observe symmetric-mode Lamb waves generated by teleseismic S-waves incident on the grounding zones. Despite their complexity, we conclude that teleseismic coda can be utilized for passive imaging of sub-shelf Earth structure, although longer deployments relative to conventional land-sited seismometers will be necessary to acquire adequate data.
    Description: This research was supported by NSF grants PLR-1142518, 1141916, 1142126, 1246151, 1246416 and OPP-1744852 and 1744856.
    Keywords: Glacier geophysics ; Ice shelves ; Seismology
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    facet.materialart.
    Unknown
    Cambridge University Press
    Publication Date: 2022-10-26
    Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in McNichol, A., Key, R., & Guilderson, T. Global ocean radiocarbon programs. Radiocarbon, (2022): 1–13, https://doi.org/10.1017/rdc.2022.17.
    Description: The importance of studying the radiocarbon content of dissolved inorganic carbon (DI14C) in the oceans has been recognized for decades. Starting with the GEOSECS program in the 1970s, 14C sampling has been a part of most global survey programs. Early results were used to study air-sea gas exchange while the more recent results are critical for helping calibrate ocean general circulation models used to study the effects of climate change. Here we summarize the major programs and discuss some of the important insights the results are starting to provide.
    Description: Authors received funding from the National Science Foundation OCE-85865400 (APM) and a Woods Hole Oceanographic Technical Staff Award (APM).
    Keywords: Dissolved inorganic carbon ; Ocean models ; Oceanography ; Radiocarbon
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2022-10-20
    Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ackley, S. F., Perovich, D. K., Maksym, T., Weissling, B., & Xie, H. Surface flooding of Antarctic summer sea ice. Annals of Glaciology, 61(82), (2020): 117-126, doi:10.1017/aog.2020.22.
    Description: The surface flooding of Antarctic sea ice in summer covers 50% or more of the sea-ice area in the major summer ice packs, the western Weddell and the Bellingshausen-Amundsen Seas. Two CRREL ice mass-balance buoys were deployed on the Amundsen Sea pack in late December 2010 from the icebreaker Oden, bridging the summer period (January–February 2011). Temperature records from thermistors embedded vertically in the snow and ice showed progressive increases in the depth of the flooded layer (up to 0.3–0.35 m) on the ice cover during January and February. While the snow depth was relatively unchanged from accumulation (〈10 cm), ice thickness decreased by up to a meter from bottom melting during this period. Contemporaneous with the high bottom melting, under-ice water temperatures up to 1°C above the freezing point were found. The high temperature arises from solar heating of the upper mixed layer which can occur when ice concentration in the local area falls and lower albedo ocean water is exposed to radiative heating. The higher proportion of snow ice found in the Amundsen Sea pack ice therefore results from both winter snowfall and summer ice bottom melt found here that can lead to extensive surface flooding.
    Description: This work was supported by the National Science Foundation grant to UTSA, ANT-0839053-Sea Ice System in Antarctic Summer (S.F. Ackley, H. Xie and B. Weissling), and to WHOI, ANT-1341513 (T. Maksym), and by the NASA Center for Advanced Measurements in Extreme Environments or NASA-CAMEE at UTSA, NASA #80NSSC19M0194 (S.F. Ackley, H. Xie, B.Weissling).
    Keywords: Ice/ocean interactions ; Sea ice ; Sea-ice growth and decay ; Snow/ice surface processes
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2022-10-26
    Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Reimer, P. J., Austin, W. E. N., Bard, E., Bayliss, A., Blackwell, P. G., Ramsey, C. B., Butzin, M., Cheng, H., Edwards, R. L., Friedrich, M., Grootes, P. M., Guilderson, T. P., Hajdas, I., Heaton, T. J., Hogg, A. G., Hughen, K. A., Kromer, B., Manning, S. W., Muscheler, R., Palmer, J. G., Pearson, C., van der Plicht, J., Reimer, R. W., Richards, D. A., Scott, E. M., Southon, J. R., Turney, C. S. M., Wacker, L., Adolphi, F., Buentgen, U., Capano, M., Fahrni, S. M., Fogtmann-Schulz, A., Friedrich, R., Koehler, P., Kudsk, S., Miyake, F., Olsen, J., Reinig, F., Sakamoto, M., Sookdeo, A., & Talamo, S. The Intcal20 Northern Hemisphere radiocarbon age calibration curve (0-55 cal kBP). Radiocarbon, 62(4), (2020): 725-757, doi:10.1017/RDC.2020.41.
    Description: Radiocarbon (14C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international 14C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable 14C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the 14C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine 14C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.
    Description: We would like to thank the National Natural Science Foundation of China grants NSFC 41888101 and NSFC 41731174, the 111 program of China (D19002), U.S. NSF Grant 1702816, and the Malcolm H. Wiener Foundation for support for research that contributed to the IntCal20 curve. The work on the Swiss and German YD trees was funded by the German Science foundation and the Swiss National Foundation (grant number: 200021L_157187). The operation in Aix-en-Provence is funded by the EQUIPEX ASTER-CEREGE, the Collège de France and the ANR project CARBOTRYDH (to EB). The work on the correlation of tree ring 14C with ice core 10Be was partially supported by the Swedish Research Council and the Knut and Alice Wallenberg foundation. M. Butzin was supported by the German Federal Ministry of Education and Research (BMBF) as Research for Sustainable Development (FONA; http://www.fona.de) through the PalMod project (grant number: 01LP1505B). S. Talamo and M. Friedrich are funded by the European Research Council under the European Union’s Horizon 2020 Research and Innovation Programme (grant agreement No. 803147-RESOLUTION, awarded to ST). CA. Turney would like to acknowledge support of the Australian Research Council (FL100100195 and DP170104665). P. Reimer and W. Austin acknowledge the support of the UKRI Natural Environment Research Council (Grant NE/M004619/1). T.J. Heaton is supported by a Leverhulme Trust Fellowship RF-2019-140\9. Other datasets and the IntCal20 database were created without external support through internal funding by the respective laboratories. We also would like to thank various institutions that provided funding or facilities for meetings.
    Keywords: Calibration curve ; Radiocarbon ; IntCal20
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2022-10-26
    Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Druffel, E., Beaupre, S., Grotheer, H., Lewis, C., McNichol, A., Mollenhauer, G., & Walker, B. Marine organic carbon and radiocarbon – present and future challenges. Radiocarbon, (2022): 1-17, https://doi.org/10.1017/RDC.2021.105.
    Description: We discuss present and developing techniques for studying radiocarbon in marine organic carbon (C). Bulk DOC (dissolved organic C) Δ14C measurements reveal information about the cycling time and sources of DOC in the ocean, yet they are time consuming and need to be streamlined. To further elucidate the cycling of DOC, various fractions have been separated from bulk DOC, through solid phase extraction of DOC, and ultrafiltration of high and low molecular weight DOC. Research using 14C of DOC and particulate organic C separated into organic fractions revealed that the acid insoluble fraction is similar in 14C signature to that of the lipid fraction. Plans for utilizing this methodology are described. Studies using compound specific radiocarbon analyses to study the origin of biomarkers in the marine environment are reviewed and plans for the future are outlined. Development of ramped pyrolysis oxidation methods are discussed and scientific questions addressed. A modified elemental analysis (EA) combustion reactor is described that allows high particulate organic C sample throughput by direct coupling with the MIniCArbonDAtingSystem.
    Keywords: CSRA ; Dissolved organic carbon ; Methodology ; Organic carbon ; Radiocarbon
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Publication Date: 2022-10-26
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Priscu, J. C., Kalin, J., Winans, J., Campbell, T., Siegfried, M. R., Skidmore, M., Dore, J. E., Leventer, A., Harwood, D. M., Duling, D., Zook, R., Burnett, J., Gibson, D., Krula, E., Mironov, A., McManis, J., Roberts, G., Rosenheim, B. E., Christner, B. C., Kasic, K., Fricker, H. A., Lyons, W. B., Barker, J., Bowling, M., Collins, B., Davis, C., Gagnon, A., Gardner, C., Gustafson, C., Kim, O-S., Li, W., Michaud, A., Patterson, M. O., Tranter, M., Ryan Venturelli, R., Trista Vick-Majors, T., & Elsworth, C. Scientific access into Mercer Subglacial Lake: scientific objectives, drilling operations and initial observations. Annals of Glaciology, 62(85–86), (2021): 340–352, https://doi.org/10.1017/aog.2021.10.
    Description: The Subglacial Antarctic Lakes Scientific Access (SALSA) Project accessed Mercer Subglacial Lake using environmentally clean hot-water drilling to examine interactions among ice, water, sediment, rock, microbes and carbon reservoirs within the lake water column and underlying sediments. A ~0.4 m diameter borehole was melted through 1087 m of ice and maintained over ~10 days, allowing observation of ice properties and collection of water and sediment with various tools. Over this period, SALSA collected: 60 L of lake water and 10 L of deep borehole water; microbes 〉0.2 μm in diameter from in situ filtration of ~100 L of lake water; 10 multicores 0.32–0.49 m long; 1.0 and 1.76 m long gravity cores; three conductivity–temperature–depth profiles of borehole and lake water; five discrete depth current meter measurements in the lake and images of ice, the lake water–ice interface and lake sediments. Temperature and conductivity data showed the hydrodynamic character of water mixing between the borehole and lake after entry. Models simulating melting of the ~6 m thick basal accreted ice layer imply that debris fall-out through the ~15 m water column to the lake sediments from borehole melting had little effect on the stratigraphy of surficial sediment cores.
    Description: This material is based upon work supported by the US National Science Foundation, Section for Antarctic Sciences, Antarctic Integrated System Science program as part of the interdisciplinary (Subglacial Antarctic Lakes Scientific Access (SALSA): Integrated study of carbon cycling in hydrologically-active subglacial environments) project (NSF-OPP 1543537, 1543396, 1543405, 1543453 and 1543441). Ok-Sun Kim was funded by the Korean Polar Research Institute. We are particularly thankful to the SALSA traverse personnel for crucial technical and logistical support. The United States Antarctic Program enabled our fieldwork; the New York Air National Guard and Kenn Borek Air provided air support; UNAVCO provided geodetic instrument support. Hot water drilling activities, including repair and upgrade modifications of the WISSARD hot water drill system, for the SALSA project were supported by a subaward from the Ice Drilling Program of Dartmouth College (NSF-PLR 1327315) to the University of Nebraska-Lincoln. J. Lawrence assisted with manuscript preparation. Finally, we are grateful to C. Dean, the SALSA Project Manager, and R. Ricards, SALSA Project Coordinator at McMurdo Station, for their organizational skills, and B. Huber of Lamont-Doherty Earth Observatory for providing the SBE39 PT sensors and the Nortek Aquadopp current meter and assisting with interpretation of the data. B. Huber also provided helpful input on programing and calibrating the SBE19PlusV2 6112 CTD.
    Keywords: Antarctic glaciology ; Basal ice ; Biogeochemistry ; Glacial sedimentology ; Subglacial lakes
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Publication Date: 2022-05-27
    Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Tison, J.-L., Maksym, T., Fraser, A. D., Corkill, M., Kimura, N., Nosaka, Y., Nomura, D., Vancoppenolle, M., Ackley, S., Stammerjohn, S., Wauthy, S., Van der Linden, F., Carnat, G., Sapart, C., de Jong, J., Fripiat, F., & Delille, B. Physical and biological properties of early winter Antarctic sea ice in the Ross Sea. Annals of Glaciology, 61(83), (2020): 241–259, https://doi.org/10.1017/aog.2020.43.
    Description: This work presents the results of physical and biological investigations at 27 biogeochemical stations of early winter sea ice in the Ross Sea during the 2017 PIPERS cruise. Only two similar cruises occurred in the past, in 1995 and 1998. The year 2017 was a specific year, in that ice growth in the Central Ross Sea was considerably delayed, compared to previous years. These conditions resulted in lower ice thicknesses and Chl-a burdens, as compared to those observed during the previous cruises. It also resulted in a different structure of the sympagic algal community, unusually dominated by Phaeocystis rather than diatoms. Compared to autumn-winter sea ice in the Weddell Sea (AWECS cruise), the 2017 Ross Sea pack ice displayed similar thickness distribution, but much lower snow cover and therefore nearly no flooding conditions. It is shown that contrasted dynamics of autumnal-winter sea-ice growth between the Weddell Sea and the Ross Sea impacted the development of the sympagic community. Mean/median ice Chl-a concentrations were 3–5 times lower at PIPERS, and the community status there appeared to be more mature (decaying?), based on Phaeopigments/Chl-a ratios. These contrasts are discussed in the light of temporal and spatial differences between the two cruises.
    Description: S. Stammerjohn was supported by the PIPERS and LTER Programs of the U.S. National Science Foundation, ANT-1341606 (S. Stammerjohn and J. Cassano, U Colorado) and ANT-0823101 (H. Ducklow, LDEO/Columbia University), respectively. Steve Ackley (UTSA) was supported by the PIPERS program of the U.S. National Science Foundation ANT-1341717 and by NASA Grant 80NSSC19M0194 to the Center for Adv. Meas. in Extreme Environments at UTSA.Ted Maksym (WHOI) was supported by the PIPERS program of the U.S. National Science Foundation ANT-1341513. This research was supported by the Belgian F.R.S-FNRS (project ISOGGAP and IODIne, contract T.0268.16 and J.0262.17, respectively). Fanny Van der Linden, Sarah Wauthy, Gauthier Carnat, Célia Sapart and Bruno Delille are PhD students, postdoctoral researchers and research associate, respectively, of the Belgian F.R.S.-FNRS. This work was also supported by the Australian Government's Cooperative Research Centre program through the Antarctic Climate & Ecosystems Cooperative Research Centre, and by the Australian Research Council's Special Research Initiative for Antarctic Gateway Partnership (Project ID SR140300001). Daiki Nomura was supported by grants from the Japan Society for the Promotion of Science (#17H04715) and the National Institute for Polar Research through Project Research KP-303 (ROBOTICA) and #28-14.
    Keywords: Antarctic glaciology ; biogeochemistry ; sea ice
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    facet.materialart.
    Unknown
    Cambridge University Press
    In:  EPIC3Climate Change 2022: Impacts, adaptation and vulnerability. Contribution of the WGII to the 6th assessment report of the intergovernmental panel on climate change, ,, IPCC AR6 WGII, https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_FinalDraft_Chapter03.pdf, Cambridge University Press
    Publication Date: 2022-08-23
    Repository Name: EPIC Alfred Wegener Institut
    Type: Inbook , NonPeerReviewed
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    facet.materialart.
    Unknown
    Cambridge University Press
    In:  EPIC3Climate Change 2022: Impacts, adaptation and vulnerability. Contribution of the WGII to the 6th assessment report of the intergovernmental panel on climate change, IPCC AR6 WGII, Climate Change 2022: Impacts, adaptation and vulnerability. Contribution of the WGII to the 6th assessment report of the intergovernmental panel on climate change, IPCC AR6 WGII, https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_FinalDraft_Chapter02.pdf, Cambridge University Press, 5 p., pp. 22-26
    Publication Date: 2022-06-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: Inbook , peerRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Publication Date: 2022-07-20
    Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Tan, S., Pratt, L. J., Voet, G., Cusack, J. M., Helfrich, K. R., Alford, M. H., Girton, J. B., & Carter, G. S. Hydraulic control of flow in a multi-passage system connecting two basins. Journal of Fluid Mechanics, 940, (2022): A8, https://doi.org/10.1017/jfm.2022.212.
    Description: When a fluid stream in a conduit splits in order to pass around an obstruction, it is possible that one branch will be critically controlled while the other remains not so. This is apparently the situation in Pacific Ocean abyssal circulation, where most of the northward flow of Antarctic bottom water passes through the Samoan Passage, where it is hydraulically controlled, while the remainder is diverted around the Manihiki Plateau and is not controlled. These observations raise a number of questions concerning the dynamics necessary to support such a regime in the steady state, the nature of upstream influence and the usefulness of rotating hydraulic theory to predict the partitioning of volume transport between the two paths, which assumes the controlled branch is inviscid. Through the use of a theory for constant potential vorticity flow and accompanying numerical model, we show that a steady-state regime similar to what is observed is dynamically possible provided that sufficient bottom friction is present in the uncontrolled branch. In this case, the upstream influence that typically exists for rotating channel flow is transformed into influence into how the flow is partitioned. As a result, the partitioning of volume flux can still be reasonably well predicted with an inviscid theory that exploits the lack of upstream influence.
    Description: This work was supported by the National Science Foundation under grants OCE-1029268, OCE-1029483, OCE-1657264, OCE-1657795, OCE-1657870 and OCE-1658027.
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Publication Date: 2022-05-26
    Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Heaton, T. J., Koehler, P., Butzin, M., Bard, E., Reimer, R. W., Austin, W. E. N., Ramsey, C. B., Grootes, P. M., Hughen, K. A., Kromer, B., Reimer, P. J., Adkins, J., Burke, A., Cook, M. S., Olsen, J., & Skinner, L. C. Marine20-the marine radiocarbon age calibration curve (0-55,000 cal BP). Radiocarbon, 62(4), (2020): 779-820, doi:10.1017/RDC.2020.68.
    Description: The concentration of radiocarbon (14C) differs between ocean and atmosphere. Radiocarbon determinations from samples which obtained their 14C in the marine environment therefore need a marine-specific calibration curve and cannot be calibrated directly against the atmospheric-based IntCal20 curve. This paper presents Marine20, an update to the internationally agreed marine radiocarbon age calibration curve that provides a non-polar global-average marine record of radiocarbon from 0–55 cal kBP and serves as a baseline for regional oceanic variation. Marine20 is intended for calibration of marine radiocarbon samples from non-polar regions; it is not suitable for calibration in polar regions where variability in sea ice extent, ocean upwelling and air-sea gas exchange may have caused larger changes to concentrations of marine radiocarbon. The Marine20 curve is based upon 500 simulations with an ocean/atmosphere/biosphere box-model of the global carbon cycle that has been forced by posterior realizations of our Northern Hemispheric atmospheric IntCal20 14C curve and reconstructed changes in CO2 obtained from ice core data. These forcings enable us to incorporate carbon cycle dynamics and temporal changes in the atmospheric 14C level. The box-model simulations of the global-average marine radiocarbon reservoir age are similar to those of a more complex three-dimensional ocean general circulation model. However, simplicity and speed of the box model allow us to use a Monte Carlo approach to rigorously propagate the uncertainty in both the historic concentration of atmospheric 14C and other key parameters of the carbon cycle through to our final Marine20 calibration curve. This robust propagation of uncertainty is fundamental to providing reliable precision for the radiocarbon age calibration of marine based samples. We make a first step towards deconvolving the contributions of different processes to the total uncertainty; discuss the main differences of Marine20 from the previous age calibration curve Marine13; and identify the limitations of our approach together with key areas for further work. The updated values for ΔR, the regional marine radiocarbon reservoir age corrections required to calibrate against Marine20, can be found at the data base http://calib.org/marine/.
    Description: We would like to thank Jeremy Oakley and Richard Bintanja for informative discussions during the development of this work. T.J. Heaton is supported by a Leverhulme Trust Fellowship RF-2019-140\9, “Improving the Measurement of Time Using Radiocarbon”. M Butzin is supported by the German Federal Ministry of Education and Research (BMBF), as Research for Sustainability initiative (FONA); www.fona.de through the PalMod project (grant numbers: 01LP1505B, 01LP1919A). E. Bard is supported by EQUIPEX ASTER-CEREGE and ANR CARBOTRYDH. Meetings of the IntCal Marine Focus group have been supported by Collège de France. Data are available on the PANGAEA database at doi:10.159/ANGAEA.914500.
    Keywords: Bayesian modeling ; calibration ; carbon cycle ; computer model ; marine environment
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Publication Date: 2022-10-26
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in [Schiller, C. M., Whitlock, C., Elder, K. L., Iverson, N. A., & Abbott, M. B. Erroneously old radiocarbon ages from terrestrial pollen concentrates in Yellowstone Lake, Wyoming, USA. Radiocarbon, 63(1), (2021): 321-342, https://doi.org/10.1017/RDC.2020.118.
    Description: Accelerator mass spectrometry (AMS) dating of pollen concentrates is often used in lake sediment records where large, terrestrial plant remains are unavailable. Ages produced from chemically concentrated pollen as well as manually picked Pinaceae grains in Yellowstone Lake (Wyoming) sediments were consistently 1700–4300 cal years older than ages established by terrestrial plant remains, tephrochronology, and the age of the sediment-water interface. Previous studies have successfully utilized the same laboratory space and methods, suggesting the source of old-carbon contamination is specific to these samples. Manually picking pollen grains precludes admixture of non-pollen materials. Furthermore, no clear source of old pollen grains occurs on the deglaciated landscape, making reworking of old pollen grains unlikely. High volumes of CO2 are degassed in the Yellowstone Caldera, potentially introducing old carbon to pollen. While uptake of old CO2 through photosynthesis is minor (F14C approximately 0.99), old-carbon contamination may still take place in the water column or in surficial lake sediments. It remains unclear, however, what mechanism allows for the erroneous ages of highly refractory pollen grains while terrestrial plant remains were unaffected. In the absence of a satisfactory explanation for erroneously old radiocarbon ages from pollen concentrates, we propose steps for further study.
    Description: This research was supported by NSF Grant No. 1515353 to C. Whitlock and sampling in Yellowstone National Park was conducted under permits YELL-SCI-0009 and YELL-SCI-5054.
    Keywords: AMS dating ; Chronology ; Contamination ; Paleoecology ; Pine
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Publication Date: 2022-10-26
    Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Roberts, Mark L., Elder, Kathryn L., Jenkins, William J., Gagnon, Alan R., Xu, Li, Hlavenka, Joshua D., & Longworth, Brett E. C-14 Blank Corrections for 25-100 mu G samples at the National Ocean Sciences AMS Laboratory. Radiocarbon, 61(5), (2019): 1403-1411, Doi: 10.1017/RDC.2019.74.
    Description: Replicate radiocarbon (14C) measurements of organic and inorganic control samples, with known Fraction Modern values in the range Fm = 0–1.5 and mass range 6 μg–2 mg carbon, are used to determine both the mass and radiocarbon content of the blank carbon introduced during sample processing and measurement in our laboratory. These data are used to model, separately for organic and inorganic samples, the blank contribution and subsequently “blank correct” measured unknowns in the mass range 25–100 μg. Data, formulas, and an assessment of the precision and accuracy of the blank correction are presented.
    Description: This work is supported by a Cooperative Agreement (OCE-1755125) with the U.S. National Science Foundation.
    Keywords: AMS ; AMS dating ; Blank corrections
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Publication Date: 2022-10-26
    Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Baker, M. G., Aster, R. C., Anthony, R. E., Chaput, J., Wiens, D. A., Nyblade, A., Bromirski, P. D., Gerstoft, P., & Stephen, R. A. Seasonal and spatial variations in the ocean-coupled ambient wavefield of the Ross Ice Shelf. Journal of Glaciology, 65(254), (2019): 912-925, doi:10.1017/jog.2019.64.
    Description: The Ross Ice Shelf (RIS) is host to a broadband, multimode seismic wavefield that is excited in response to atmospheric, oceanic and solid Earth source processes. A 34-station broadband seismographic network installed on the RIS from late 2014 through early 2017 produced continuous vibrational observations of Earth's largest ice shelf at both floating and grounded locations. We characterize temporal and spatial variations in broadband ambient wavefield power, with a focus on period bands associated with primary (10–20 s) and secondary (5–10 s) microseism signals, and an oceanic source process near the ice front (0.4–4.0 s). Horizontal component signals on floating stations overwhelmingly reflect oceanic excitations year-round due to near-complete isolation from solid Earth shear waves. The spectrum at all periods is shown to be strongly modulated by the concentration of sea ice near the ice shelf front. Contiguous and extensive sea ice damps ocean wave coupling sufficiently so that wintertime background levels can approach or surpass those of land-sited stations in Antarctica.
    Description: This research was supported by NSF grants PLR-1142518, 1141916, 1142126, 1246151 and 1246416. JC was additionally supported by Yates funds in the Colorado State University Department of Mathematics. PDB also received support from the California Department of Parks and Recreation, Division of Boating and Waterways under contract 11-106-107. We thank Reinhard Flick and Patrick Shore for their support during field work, Tom Bolmer in locating stations and preparing maps, and the US Antarctic Program for logistical support. The seismic instruments were provided by the Incorporated Research Institutions for Seismology (IRIS) through the PASSCAL Instrument Center at New Mexico Tech. Data collected are available through the IRIS Data Management Center under RIS and DRIS network code XH. The PSD-PDFs presented in this study were processed with the IRIS Noise Tool Kit (Bahavar and others, 2013). The facilities of the IRIS Consortium are supported by the National Science Foundation under Cooperative Agreement EAR-1261681 and the DOE National Nuclear Security Administration. The authors appreciate the support of the University of Wisconsin-Madison Automatic Weather Station Program for the data set, data display and information; funded under NSF grant number ANT-1543305. The Ross Ice Shelf profiles were generated using the Antarctic Mapping Tools (Greene and others, 2017). Regional maps were generated with the Generic Mapping Tools (Wessel and Smith, 1998). Topography and bathymetry data for all maps in this study were sourced from the National Geophysical Data Center ETOPO1 Global Relief Model (doi:10.7289/V5C8276M). We thank two anonymous reviewers for suggestions on the scope and organization of this paper.
    Keywords: Antarctic glaciology ; Ice shelves ; Seismology
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Publication Date: 2022-10-26
    Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Xu, L., Roberts, M., Elder, K., Hansman, R., Gagnon, A., & Kurz, M. Radiocarbon in dissolved organic carbon by UV oxidation: an update of procedures and blank characterization at NOSAMS. Radiocarbon, 64(1), (2022): 195-199, https://doi.org/10.1017/rdc.2022.4.
    Description: This note describes improvements of UV oxidation method that is used to measure carbon isotopes of dissolved organic carbon (DOC) at the National Ocean Sciences Accelerator Mass Spectrometry Facility (NOSAMS). The procedural blank is reduced to 2.6 ± 0.6 μg C, with Fm of 0.42 ± 0.10 and δ13C of –28.43 ± 1.19‰. The throughput is improved from one sample per day to two samples per day.
    Description: We gratefully acknowledge support from the U.S. National Science Foundation, via NSF-OCE-1755125.
    Keywords: Blank ; Dissolved organic carbon ; Radiocarbon ; UV-oxidation
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Publication Date: 2022-10-21
    Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ackley, S. F., Stammerjohn, S., Maksym, T., Smith, M., Cassano, J., Guest, P., Tison, J., Delille, B., Loose, B., Sedwick, P., DePace, L., Roach, L., & Parno, J. Sea-ice production and air/ice/ocean/biogeochemistry interactions in the Ross Sea during the PIPERS 2017 autumn field campaign. Annals of Glaciology, 61(82), (2020): 181-195, doi:10.1017/aog.2020.31.
    Description: The Ross Sea is known for showing the greatest sea-ice increase, as observed globally, particularly from 1979 to 2015. However, corresponding changes in sea-ice thickness and production in the Ross Sea are not known, nor how these changes have impacted water masses, carbon fluxes, biogeochemical processes and availability of micronutrients. The PIPERS project sought to address these questions during an autumn ship campaign in 2017 and two spring airborne campaigns in 2016 and 2017. PIPERS used a multidisciplinary approach of manned and autonomous platforms to study the coupled air/ice/ocean/biogeochemical interactions during autumn and related those to spring conditions. Unexpectedly, the Ross Sea experienced record low sea ice in spring 2016 and autumn 2017. The delayed ice advance in 2017 contributed to (1) increased ice production and export in coastal polynyas, (2) thinner snow and ice cover in the central pack, (3) lower sea-ice Chl-a burdens and differences in sympagic communities, (4) sustained ocean heat flux delaying ice thickening and (5) a melting, anomalously southward ice edge persisting into winter. Despite these impacts, airborne observations in spring 2017 suggest that winter ice production over the continental shelf was likely not anomalous.
    Description: NSF supported PIPERS award numbers: ANT-1341717 (S.F. Ackley, UTSA); ANT-1341513 (E. Maksym, WHOI); ANT-1341606 (S. Stammerjohn and J. Cassano, U Colorado); ANT-1341725 (P. Guest, NPS). P. Sedwick was supported by NSF ANT-1543483. S.F. Ackley was also supported by NASA Grant 80NSSC19M0194 to the Center for Advanced Measurements in Extreme Environments at UTSA. S. Stammerjohn was also supported by the LTER Program under NFS award number ANT-0823101 (H. Ducklow, LDEO/Columbia University). Additional support was by the Belgian F.R.S-FNRS (project ISOGGAP and IODIne, contract T.0268.16 and J.0262.17, respectively). Bruno Delille is a research associate of the F.R.S.-FNRS. Terra-Sar-X quicklook imagery was coordinated by Kathrin Hoeppner at DLR, and Andy Archer (with the Antarctic Support Contractor) provided selected (cloud-free) MODIS scenes and daily maps of AMSR2 sea-ice concentration.
    Keywords: Atmosphere/ice/ocean interactions ; Ice/ocean interactions ; Sea ice ; Sea-ice growth and decay
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 209-237 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 239-267 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 269-292 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 293-318 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 319-350 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 351-377 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 379-404 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 405-434 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 435-462 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 463-493 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 495-522 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 85-116 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 59-83 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 117-140 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 141-165 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 24 (1995), S. 523-549 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 25 (1996), S. 55-78 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 25 (1996), S. 113-136 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 25 (1996), S. 163-195 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 25 (1996), S. 231-258 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 25 (1996), S. 259-286 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 25 (1996), S. 197-229 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 25 (1996), S. 287-314 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 25 (1996), S. 315-342 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 25 (1996), S. 367-394 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 25 (1996), S. 431-459 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 25 (1996), S. 395-429 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 1-25 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 27-45 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract The scope and utility of phage display is reviewed with emphasis on medical applications and structure-based ligand and drug design, from literature mostly after 1994. General principles by which phage-displayed peptides achieve affinity and selectivity for targets are described, along with selected structural or mechanistic studies of the binding of peptides or proteins discovered or engineered by phage display. Such engineered proteins whose wild-type or mutant crystal or 2D-NMR structures yield insight about the basis for enhanced affinity or altered specificity include antibodies, zinc fingers, human growth hormone, protein A, and atrial natriuretic peptide. Structures of complexes of de novo phage-discovered peptide ligands with targets such as the Src SH3 domain, streptavidin, and erythropoietin receptor reveal the structural basis for receptor-peptide recognition in these systems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 83-112 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Chromatin structure is now believed to be dynamic and intimately related with cellular processes such as transcription. Over the past few years, high-resolution structures for the histones have become available. These structures and their implications for nucleosome organization are reviewed here.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 113-137 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract The evidence showing that the self-assembly of complex RNAs occurs in discrete transitions, each relating to the folding of sub-systems of increasing size and complexity starting from a state with most of the secondary structure, is reviewed. The reciprocal influence of the concentration of magnesium ions and nucleotide mutations on tertiary structure is analyzed. Several observations demonstrate that detrimental mutations can be rescued by high magnesium concentrations, while stabilizing mutations lead to a lesser dependence on magnesium ion concentration. Recent data point to the central controlling and monitoring roles of RNA-binding proteins that can bind to the different folding stages, either before full establishment of the secondary structure or at the molten globule state before the cooperative transition to the final three-dimensional structure.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 139-156 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract One of the fundamental properties of the RNA helix is its intrinsic resistance to bend- or twist-deformations. Results of a variety of physical measurements point to a persistence length of 700-800 A for double-stranded RNA in the presence of magnesium cations, approximately 1.5-2.0-fold larger than the corresponding value for DNA. Although helix flexibility represents an important, quantifiable measure of the forces of interaction within the helix, it must also be considered in describing conformational variation of nonhelix elements (e.g. internal loops, branches), since the latter always reflect the properties of the flanking helices; that is, such elements are never completely rigid. For one important element of tertiary structure, namely, the core of yeast tRNAPhe, the above consideration has led to the conclusion that the core is not substantially more flexible than an equivalent length of pure helix.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 157-179 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Phospholamban is a 52-amino-acid protein that assembles into a pentamer in sarcoplasmic reticulum membranes. The protein has a role in the regulation of the resident calcium ATPase through an inhibitory association that can be reversed by phosphorylation. The phosphorylation of phospholamban is initiated by beta-adrenergic stimulation, identifying phospholamban as an important component in the stimulation of cardiac activity by beta-agonists. It is this role of phospholamban that has motivated studies in recent decades. There is evidence that phospholamban may also function as a Ca2+-selective ion channel. The structural properties of phospholamban have been studied by mutagenesis, modeling, and spectroscopy, resulting in a new view of the organization of this key molecule in membranes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 181-222 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Innovative algorithms have been developed during the past decade for simulating Newtonian physics for macromolecules. A major goal is alleviation of the severe requirement that the integration timestep be small enough to resolve the fastest components of the motion and thus guarantee numerical stability. This timestep problem is challenging if strictly faster methods with the same all-atom resolution at small timesteps are sought. Mathematical techniques that have worked well in other multiple-timescale contexts-where the fast motions are rapidly decaying or largely decoupled from others-have not been as successful for biomolecules, where vibrational coupling is strong. This review examines general issues that limit the timestep and describes available methods (constrained, reduced-variable, implicit, symplecttic, multiple-timestep, and normal-mode-based schemes). A section compares results of selected integrators for a model dipeptide, assessing physical and numerical performance. Included is our dual timestep method LN, which relies on an approximate linearization of the equations of motion every Deltat interval (5 fs or less), the solution of which is obtained by explicit integration at the inner timestep Deltatau (e.g., 0.5 fs). LN is computationally competitive, providing 4-5 speedup factors, and results are in good agreement, in comparison to 0.5 fs trajectories. These collective algorithmic efforts help fill the gap between the time range that can be simulated and the timespans of major biological interest (milliseconds and longer). Still, only a hierarchy of models and methods, along with experimentational improvements, will ultimately give theoretical modeling the status of partner with experiment.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 223-258 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Two sensory rhodopsins (SRI and SRII) mediate color-sensitive phototaxis responses in halobacteria. These seven-helix receptor proteins, structurally and functionally similar to animal visual pigments, couple retinal photoisomerization to receptor activation and are complexed with membrane-embedded transducer proteins (HtrI and HtrII) that modulate a cytoplasmic phosphorylation cascade controlling the flagellar motor. The Htr proteins resemble the chemotaxis transducers from Escherichia coli. The SR-Htr signaling complexes allow studies of the biophysical chemistry of signal generation and relay, from the photobiophysics of initial excitation of the receptors to the final output at the level of the flagellar motor switch, revealing fundamental principles of sensory transduction and more broadly the nature of dynamic interactions between membrane proteins. We review here recent advances that have led to new insights into the molecular mechanism of signaling by these membrane complexes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 259-288 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract A characteristic feature of cellular signal transduction pathways in eukaryotes is the separation of catalysis from target recognition. Several modular domains that recognize short peptide sequences and target signaling proteins to these sequences have been identified. The structural bases of the specificities of recognition by SH2, SH3, and PTB domains have been elucidated by X-ray crystallography and NMR, and these results are reviewed here. In addition, the mechanism of cooperative interactions between these domains is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 357-371 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Zinc-finger domains are small metal-binding modules that are found in a wide range of gene regulatory proteins. Peptides corresponding to these domains have provided valuable model systems for examining a number of biophysical parameters entirely unrelated to their nucleic acid binding properties. These include the chemical basis for metal-ion affinity and selectivity, thermodynamic properties related to hydrophobic packing and beta-sheet propensities, and constraints on the generation of ligand-binding and potential catalytic sites. These studies have laid the foundation for applications such as the generation of optically detected zinc probes and the design of metal-binding peptides and proteins with desired spectroscopic and chemical properties.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 327-355 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Over the past two decades, nanosecond absorption and vibrational spectroscopies have developed into powerful tools for monitoring the secondary, tertiary, and quaternary structural relaxations of biological macromolecules under near-physiological conditions of solvent and temperature. Observed through such methods, the dynamic response of a biomolecule to photoinitiated excursions from equilibrium can reveal valuable information about the structure-function relationship, information beyond that obtained from the static structures provided by X-ray crystallography, nuclear magnetic resonance spectroscopy, and other steady-state methods. Most recently, the development of ultra-sensitive polarization techniques for absorption spectroscopy has greatly enhanced the amount of time-resolved structural information that can be obtained from the broadened electronic spectra of biomolecules. This review examines nanosecond absorption, vibrational, and polarized absorption methods, and their applications to protein function and folding, emphasizing the complementary nature of information obtained from electronic and vibrational spectra measured on the nanosecond time scale.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 289-325 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Eukaryotes have three distinct RNA polymerases that catalyze transcription of nuclear genes. RNA polymerase II is responsible for transcribing nuclear genes encoding the messenger RNAs and several small nuclear RNAs. Like RNA polymerases I and III, polymerase II cannot recognize its target promoter directly and initiate transcription without accessory factors. Instead, this large multisubunit enzyme relies on general transcription factors and transcriptional activators and coactivators to regulate transcription from class II promoters. X-ray crystallography and nuclear magnetic resonance spectroscopy have been used to study complexes of general transcription factors and transcriptional activators with their specific DNA targets. This work has provided important structural insights into transcription initiation by polymerase II and the more general problem of DNA sequence recognition.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 47-82 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Researchers have made good progress in unraveling the molecular mechanisms of excitation-contraction (EC) coupling in striated muscle. Despite this progress, paradoxes abound. In skeletal muscle, the existence of a mechanical coupling between membrane charge movement and activation of sarcoplasmic reticulum (SR) release channels is essentially established, but the contribution of Ca2+-induced Ca2+ release (CICR) to the transient and steady-state components of Ca2+ release remains controversial. In cardiac muscle, the role of CICR as the primary mechanism of EC coupling is well established, but the stability and tight coupling between membrane Ca2+ current and release are paradoxical. Answers may lie in microdomain issues, and in the examination of discrete elementary release events, although quantitative treatments are needed. This review explores the theoretical and experimental methods used and the observations made in the study of microdomain Ca2+.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 373-399 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Measurements of trajectories of individual proteins or lipids in the plasma membrane of cells show a variety of types of motion. Brownian motion is observed, but many of the particles undergo non-Brownian motion, including directed motion, confined motion, and anomalous diffusion. The variety of motion leads to significant effects on the kinetics of reactions among membrane-bound species and requires a revision of existing views of membrane structure and dynamics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 495-540 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract This review focuses on the recent advances in EPR spectroscopy as they are applied both to photoinduced electron transfer in the photosynthetic apparatus and to biomimetic systems. The review deals with time-resolved direct-detection cw and pulsed EPR and ENDOR methods, both at conventional bands [X-(9.5 GHz), K-(24 GHz), and Q-(35 GHz)] and at high frequency bands (W-band, 95 GHz, and even highter frequency bands). EPR studies on photosynthetic and model systems in their doublet, triplet and radical pair states are surveyed, including their static and dynamic properties. Applications of time-resolved EPR in studying photoinduced electron and energy transfer in isotropic and anisotropic environments, and the concepts of electron spin polarization and magnetic field effects in photochemical reactions are also reviewed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 541-566 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Surface plasmon resonance biosensors have become increasingly popular for the qualitative and quantitative characterization of the specific binding of a mobile reactant to a binding partner immobilized on the sensor surface. This article reviews the use of this new technique to measure the binding affinities and the kinetic constants of reversible interactions between biological macromolecules. Immobilization techniques, the most commonly employed experimental strategies, and various analytical approaches are summarized. In recent years, several sources of potential artifacts have been identified: immobilization of the binding partner, steric hindrance of binding to adjacent binding sites at the sensor surface, and finite rate of mass transport of the mobile reactant to the sensor surface. Described here is the influence of these artifacts on the measured binding kinetics and equilibria, together with suggested control experiments.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 597-627 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Analysis of the structures in the Protein Databank, released in June 1996, shows that the number of different protein folds, i.e. the number of different arrangements of major secondary structures and/or chain topologies, is 327. Of these folds, approximately 25% belong to the all-alpha class, 20% belong to the all-beta class, 30% belong to the alpha/beta class, and 25% belong to the alpha + beta class. We describe the types of folds now known for the all-beta and all-alpha classes, emphasizing those that have been discovered recently. Detailed theories for the physical determinants of the structures of most of these folds now exist, and these are reviewed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 27 (1998), S. 59-75 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract This review surveys the kinds of protein complex that participate in cell communication and identifies, where possible, general principles by which they form and act. It also advances the notion that biophysical constraints imposed by macromolecular crowding and diffusion have had a controlling influence on the evolution of cell signaling pathways. Complexes associated with the bacterial aspartate receptor, with eucaryotic tyrosine kinase receptors, with T-cell receptors, and with focal contacts are examined together with proteins that serve as adaptors, anchors, and scaffolds for signaling complexes. The importance of diffusion in controlling the numbers and locations of signaling complexes is discussed, as is the special role played by membranes in signaling pathways.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 27 (1998), S. 285-327 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract The substrates for the essential biological processes of transcription, replication, recombination, DNA repair, and cell division are not naked DNA; rather, they are protein-DNA complexes known as chromatin, in one or another stage of a hierarchical series of compactions. These are exciting times for students of chromatin. New studies provide incontrovertible evidence linking chromatin structure to function. Exceptional progress has been made in studies of the structure of chromatin subunits. Surprising new dynamic properties have been discovered. And, much progress has been made in dissecting the functional roles of specific chromatin proteins and domains. This review focuses on in vitro studies of chromatin structure, dynamics, and function.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 27 (1998), S. 249-284 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Retroviral protease (PR) from the human immunodeficiency virus type 1 (HIV-1) was identified over a decade ago as a potential target for structure-based drug design. This effort was very successful. Four drugs are already approved, and others are undergoing clinical trials. The techniques utilized in this remarkable example of structure-assisted drug design included crystallography, NMR, computational studies, and advanced chemical synthesis. The development of these drugs is discussed in detail. Other approaches to designing HIV-1 PR inhibitors, based on the concepts of symmetry and on the replacement of a water molecule that had been found tetrahedrally coordinated between the enzyme and the inhibitors, are also discussed. The emergence of drug-induced mutations of HIV-1 PR leads to rapid loss of potency of the existing drugs and to the need to continue the development process. The structural basis of drug resistance and the ways of overcoming this phenomenon are mentioned.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 27 (1998), S. 199-224 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Biochemical and genetic approaches have identified the molecular mechanisms of many genetic reactions, particularly in bacteria. Now a comparably detailed understanding is needed of how groupings of genes and related protein reactions interact to orchestrate cellular functions over the cell cycle, to implement preprogrammed cellular development, or to dynamically change a cell's processes and structures in response to environmental signals. Simulations using realistic, molecular-level models of genetic mechanisms and of signal transduction networks are needed to analyze dynamic behavior of multigene systems, to predict behavior of mutant circuits, and to identify the design principles applicable to design of genetic regulatory circuits. When the underlying design rules for regulatory circuits are understood, it will be far easier to recognize common circuit motifs, to identify functions of individual proteins in regulation, and to redesign circuits for altered functions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 27 (1998), S. 329-356 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Cytochrome c oxidase, the terminal enzyme of the respiratory chains of mitochondria and aerobic bacteria, catalyzes electron transfer from cytochrome c to molecular oxygen, reducing the latter to water. Electron transfer is coupled to proton translocation across the membrane, resulting in a proton and charge gradient that is then employed by the F0F1-ATPase to synthesize ATP. Over the last years, substantial progress has been made in our understanding of the structure and function of this enzyme. Spectroscopic techniques such as EPR, absorbance and resonance Raman spectroscopy, in combination with site-directed mutagenesis work, have been successfully applied to elucidate the nature of the cofactors and their ligands, to identify key residues involved in proton transfer, and to gain insight into the catalytic cycle and the structures of its intermediates. Recently, the crystal structures of a bacterial and a mitochondrial cytochrome c oxidase have been determined. In this review, we provide an overview of the crystal structures, summarize recent spectroscopic work, and combine structural and spectroscopic data in discussing mechanistic aspects of the enzyme. For the latter, we focus on the structure of the oxygen intermediates, proton-transfer pathways, and the much-debated issue of how electron transfer in the enzyme might be coupled to proton translocation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 27 (1998), S. 357-406 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract During the past thirty years, deuterium labeling has been used to improve the resolution and sensitivity of protein NMR spectra used in a wide variety of applications. Most recently, the combination of triple resonance experiments and 2H, 13C, 15N labeled samples has been critical to the solution structure determination of several proteins with molecular weights on the order of 30 kDa. Here we review the developments in isotopic labeling strategies, NMR pulse sequences, and structure-determination protocols that have facilitated this advance and hold promise for future NMR-based structural studies of even larger systems. As well, we detail recent progress in the use of solution 2H NMR methods to probe the dynamics of protein sidechains.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 27 (1998), S. 475-502 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract The hammerhead ribozyme is a small catalytic RNA that cleaves a target phosphodiester bond in a reaction dependent on divalent metal ions. Crystal structures of the hammerhead reveal the tertiary fold of an enzymatic "ground state" of the molecule; however, they do not clarify the catalytic mechanism of the ribozyme, presumably because a significant conformational rearrangement is required to reach an enzymatic transition state. The structural domains seen in the hammerhead can be related to sequence or structural motifs in transfer and ribosomal RNAs, suggesting that they represent tertiary building blocks that will be found in large, complex RNAs.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 28 (1999), S. 1-27 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract The Raman spectrum of a protein or nucleic acid consists of numerous discrete bands representing molecular normal modes of vibration and serves as a sensitive and selective fingerprint of three-dimensional structure, intermolecular interactions, and dynamics. Recent improvements in instrumentation, coupled with innovative approaches in experimental design, dramatically increase the power and scope of the method, particularly for investigations of large supramolecular assemblies. Applications are considered that involve the use of (a) time-resolved Raman spectroscopy to elucidate assembly pathways in icosahedral viruses, (b) polarized Raman microspectroscopy to determine detailed structural parameters in filamentous viruses, (c) ultraviolet-resonance Raman spectroscopy to probe selective DNA and protein residues in nucleoprotein complexes, and (d) difference Raman methods to understand mechanisms of protein/DNA recognition in gene regulatory and chromosomal complexes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 27 (1998), S. 503-528 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Pleckstrin homology (PH) motifs are approximately 100 amino-acid residues long and have been identified in nearly 100 different eukaryotic proteins, many of which participate in cell signaling and cytoskeletal regulation. Despite minimal sequence homology, the three-dimensional structures are remarkably conserved. This review gives an overview of the PH domain architecture and examines the best-studied examples in an attempt to understand their function.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 28 (1999), S. 29-56 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Transcription in eukaryotes is frequently regulated by a mechanism termed combinatorial control, whereby several different proteins must bind DNA in concert to achieve appropriate regulation of the downstream gene. X-ray crystallographic studies of multiprotein complexes bound to DNA have been carried out to investigate the molecular determinants of complex assembly and DNA binding. This work has provided important insights into the specific protein-protein and protein-DNA interactions that govern the assembly of multiprotein regulatory complexes. The results of these studies are reviewed here, and the general insights into the mechanism of combinatorial gene regulation are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 28 (1999), S. 75-100 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Analytical ultracentrifugation is a classical method of biochemistry and molecular biology. Because it is a primary technique, sedimentation can provide first-principle hydrodynamic and first-principle thermodynamic information for nearly any molecule, in a wide range of solvents and over a wide range of solute concentrations. For many questions, it is the technique of choice. This review stresses what information is available from analytical ultracentrifugation and how that information is being extracted and used in contemporary applications.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 28 (1999), S. 129-153 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Measurement of the distance between two spin label probes in proteins permits the spatial orientation of elements of defined secondary structure. By using site-directed spin labeling, it is possible to determine multiple distance constraints and thereby build tertiary and quaternary structural models as well as measure the kinetics of structural changes. New analytical methods for determining interprobe distances and relative orientations for uniquely oriented spin labels have been developed using global analysis of multifrequency electron paramagnetic resonance data. New methods have also been developed for determining interprobe distances for randomly oriented spin labels. These methods are being applied to a wide range of structural problems, including peptides, soluble proteins, and membrane proteins, that are not readily characterized by other structural techniques.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 28 (1999), S. 155-179 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Current computer simulations of biomolecules typically make use of classical molecular dynamics methods, as a very large number (tens to hundreds of thousands) of atoms are involved over timescales of many nanoseconds. The methodology for treating short-range bonded and van der Waals interactions has matured. However, long-range electrostatic interactions still represent a bottleneck in simulations. In this article, we introduce the basic issues for an accurate representation of the relevant electrostatic interactions. In spite of the huge computational time demanded by most biomolecular systems, it is no longer necessary to resort to uncontrolled approximations such as the use of cutoffs. In particular, we discuss the Ewald summation methods, the fast particle mesh methods, and the fast multipole methods. We also review recent efforts to understand the role of boundary conditions in systems with long-range interactions, and conclude with a short perspective on future trends.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 28 (1999), S. 101-128 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Recent structural and biochemical studies have begun to illuminate how cells solve the problems of recognizing and removing damaged DNA bases. Bases damaged by environmental, chemical, or enzymatic mechanisms must be efficiently found within a large excess of undamaged DNA. Structural studies suggest that a rapid damage-scanning mechanism probes for both conformational deviations and local deformability of the DNA base stack. At susceptible lesions, enzyme-induced conformational changes lead to direct interactions with specific damaged bases. The diverse array of damaged DNA bases are processed through a two-stage pathway in which damage-specific enzymes recognize and remove the base lesion, creating a common abasic site intermediate that is processed by damage-general repair enzymes to restore the correct DNA sequence.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 28 (1999), S. 181-204 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract A significant number of exciting papain-like cysteine protease structures have been determined by crystallographic methods over the last several years. This trove of data allows for an analysis of the structural features that empower these molecules as they efficiently carry out their specialized tasks. Although the structure of the paradigm for the family, papain, has been known for twenty years, recent efforts have reaped several structures of specialized mammalian enzymes. This review first covers the commonalities of architecture and purpose of the papain-like cysteine proteases. From that broad platform, each of the lysosomal enzymes for which there is an X-ray structure (or structures) is then examined to gain an understanding of what structural features are used to customize specificity and activity. Structure-based design of inhibitors to control pathological cysteine protease activity will also be addressed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 28 (1999), S. 269-293 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract For nuclear magnetic resonance determinations of the conformation of oligosaccharides in solution, simple molecular mechanics calculations and nuclear Overhauser enhancement measurements are adequate for small oligosaccharides that adopt single, relatively rigid conformations. Polysaccharides and larger or more flexible oligosaccharides generally require additional types of data, such as scalar and dipolar coupling constants, which are most conveniently measured in 13C-enriched samples. Nuclear magnetic resonance relaxation data provide information on the dynamics of oligosaccharides, which involves several different types of internal motion. Oligosaccharides complexed with lectins and antibodies have been successfully studied both by X-ray crystallography and by nuclear magnetic resonance spectroscopy. The complexes have been shown to be stabilized by a combination of polar hydrogen bonding interactions and van der Waals attractions. Although theoretical calculations of the conformation and stability of free oligosaccharides and of complexes with proteins can be carried out by molecular mechanics methods, the role of solvent water for these highly polar molecules continues to present computational problems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 28 (1999), S. 295-317 
    ISSN: 1056-8700
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Notes: Abstract Proteasomes are large multisubunit proteases that are found in the cytosol, both free and attached to the endoplasmic reticulum, and in the nucleus of eukaryotic cells. Their ubiquitous presence and high abundance in these compartments reflects their central role in cellular protein turnover. Proteasomes recognize, unfold, and digest protein substrates that have been marked for degradation by the attachment of a ubiquitin moiety. Individual subcomplexes of the complete 26S proteasome are involved in these different tasks: The ATP-dependent 19S caps are believed to unfold substrates and feed them to the actual protease, the 20S proteasome. This core particle appears to be more ancient than the ubiquitin system. Both prokaryotic and archaebacterial ancestors have been identified. Crystal structures are now available for the E. coli proteasome homologue and the T. acidophilum and S. cerevisiae 20S proteasomes. All three enzymes are cylindrical particles that have their active sites on the inner walls of a large central cavity. They share the fold and a novel catalytic mechanism with an N-terminal nucleophilic threonine, which places them in the family of Ntn (N terminal nucleophile) hydrolases. Evolution has added complexity to the comparatively simple prokaryotic prototype. This minimal proteasome is a homododecamer made from two hexameric rings stacked head to head. Its heptameric version is the catalytic core of archaebacterial proteasomes, where it is sandwiched between two inactive antichambers that are made up from a different subunit. In eukaryotes, both subunits have diverged into seven different subunits each, which are present in the particle in unique locations such that a complex dimer is formed that has six active sites with three major specificities that can be attributed to individual subunits. Genetic, biochemical, and high-resolution electron microscopy data, but no crystal structures, are available for the 19S caps. A first step toward a mechanistic understanding of proteasome activation and regulation has been made with the elucidation of the X-ray structure of the alternative, mammalian proteasome activator PA28.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 11 (1995), S. 35-71 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 11 (1995), S. 241-265 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 11 (1995), S. 497-518 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 11 (1995), S. 633-675 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 12 (1996), S. 1-26 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract Most chloroplast proteins are nuclear encoded, synthesized as larger precursor proteins in the cytosol, posttranslationally imported into the organelle, and routed to one of six different compartments. Import across the outer and inner envelope membranes into the stroma is the major means for entry of proteins destined for the stroma, the thylakoid membrane, and the thylakoid lumen. Recent investigations have identified several unique protein components of the envelope translocation machinery. These include two GTP-binding proteins that appear to participate in the early events of import and probably regulate precursor recognition and advancement into the translocon. Localization of imported precursor proteins to the thylakoid membrane and thylakoid lumen is accomplished by four distinct mechanisms; two are homologous to bacterial and endoplasmic reticulum protein transport systems, one appears unique, and the last may be a spontaneous mechanism. Thus chloroplast protein targeting is a unique and surprisingly complex process. The presence of GTP-binding proteins in the envelope translocation machinery indicates a different precursor recognition process than is present in mitochondria. Mechanisms for thylakoid protein localization are in part derived from the prokaryotic endosymbiont, but are more unusual and diverse than expected.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 12 (1996), S. 181-220 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract Receptors for the Fc domain of immunoglobulins play an important role in immune defense. There are two well-defined functional classes of mammalian receptors. One class of receptors transports immunoglobulins across epithelial tissues to their main sites of action. This class includes the neonatal Fc receptor (FcRn), which transports immunoglobulin G (IgG), and the polymeric immunoglobulin receptor (pIgR), which transports immunoglobulin A (IgA) and immunoglobulin M (IgM). Another class of receptors present on the surfaces of effector cells triggers various biological responses upon binding antibody-antigen complexes. Of these, the IgG receptors (FcgammaR) and immunoglobulin E (IgE) receptors (FcepsilonR) are the best characterized. The biological responses elicited include antibody-dependent, cell-mediated cytotoxicity, phagocytosis, release of inflammatory mediators, and regulation of lymphocyte proliferation and differentiation. We summarize the current knowledge of the structures and functions of FcRn, pIgR, and the FcgammaR and FcepsilonRI proteins, concentrating on the interactions of the extracellular portions of these receptors with immunoglobulins.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 12 (1996), S. 335-363 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract Peroxisome proliferator-activated receptors (PPARs) are lipid-activated transcription factors that belong to the steroid/thyroid/retinoic acid receptor superfamily. All their characterized target genes encode proteins that participate in lipid homeostasis. The recent finding that antidiabetic thiazolidinediones and adipogenic prostanoids are ligands of one of the PPARs reveals a novel signaling pathway that directly links these compounds to processes involved in glucose homeostasis and lipid metabolism including adipocyte differentiation. A detailed understanding of this pathway could designate PPARs as targets for the development of novel efficient treatments for several metabolic disorders.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 12 (1996), S. 441-461 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract Proteins that function in transport vesicle docking are being identified at a rapid rate. So-called v- and t-SNAREs form the core of a vesicle docking complex. Additional accessory proteins are required to protect SNAREs from promiscuous binding and to deprotect SNAREs under conditions in which transport vesicle docking should occur. Because access to SNAREs must be regulated, other proteins must also contain specificity determinants to accomplish delivery of transport vesicles to their distinct and specific membrane targets.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 12 (1996), S. 417-439 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract Myosin is a highly conserved, ubiquitous protein found in all eukaryotic cells, where it provides the motor function for diverse movements such as cytokinesis, phagocytosis, and muscle contraction. All myosins contain an amino-terminal motor/head domain and a carboxy-terminal tail domain. Due to the extensive number of different molecules identified to date, myosins have been divided into seven distinct classes based on the properties of the head domain. One such class, class II myosins, consists of the conventional two-headed myosins that form filaments and are composed of two myosin heavy chain (MYH) subunits and four myosin light chain subunits. The MYH subunit contains the ATPase activity providing energy that is the driving force for contractile processes mentioned above, and numerous MYH isoforms exist in vertebrates to carry out this function. The MYHs involved in striated muscle contraction in mammals are the focus of the current review. The genetics, molecular biology, and biochemical properties of mammalian MYHs are discussed below. MYH gene expression patterns in developing and adult striated muscles are described in detail, as are studies of regulation of MYH genes in the heart. The discovery that mutant MYH isoforms have a causal role in the human disease familial hypertrophic cardiomyopathy (FHC) has implemented structure/function investigations of MYHs. The regulation of MYH genes expressed in skeletal muscle and the potential functional implications that distinct MYH isoforms may have on muscle physiology are addressed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 12 (1996), S. 697-715 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract Proteins that contain the Arg-Gly-Asp (RGD) attachment site, together with the integrins that serve as receptors for them, constitute a major recognition system for cell adhesion. The RGD sequence is the cell attachment site of a large number of adhesive extracellular matrix, blood, and cell surface proteins, and nearly half of the over 20 known integrins recognize this sequence in their adhesion protein ligands. Some other integrins bind to related sequences in their ligands. The integrin-binding activity of adhesion proteins can be reproduced by short synthetic peptides containing the RGD sequence. Such peptides promote cell adhesion when insolubilized onto a surface, and inhibit it when presented to cells in solution. Reagents that bind selectively to only one or a few of the RGD-directed integrins can be designed by cyclizing peptides with selected sequences around the RGD and by synthesizing RGD mimics. As the integrin-mediated cell attachment influences and regulates cell migration, growth, differentiation, and apoptosis, the RGD peptides and mimics can be used to probe integrin functions in various biological systems. Drug design based on the RGD structure may provide new treatments for diseases such as thrombosis, osteoporosis, and cancer.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 1-23 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract Transcriptional regulation is important in all eukaryotic organisms for cell growth, development, and responses to environmental change. Saccharomyces cerevisiae, or bakers' yeast, has provided a powerful system for genetic analysis of transcriptional regulation, and findings from the study of this model system have proven broadly applicable to higher organisms. Transcriptional regulation requires the interactions of regulatory proteins with various components of the transcription machinery. Recently, genetic analysis of a diverse set of transcriptional regulatory responses has converged with studies of the function of the RNA polymerase II carboxy-terminal domain (CTD) to reveal regulatory roles for proteins associated with the CTD. These proteins, designated Srb/mediator proteins, are broadly involved in both positive and negative regulatory responses in vivo. This review focuses on the connections between genetic analysis of transcriptional regulation and the functions of the Srb/mediator proteins associated with the RNA polymerase II CTD.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 53-82 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract Most animal species exhibit left-right asymmetry in their body plans and show a strong bias for one handedness over the other. The mechanism of handedness choice, recognized as an intriguing problem over a century ago, is still a mystery. However, from recent advances in understanding when and how asymmetry arises in both invertebrates and vertebrates, developmental pathways for establishment and maintenance of left-right differences are beginning to take shape, and speculations can be made on the initial choice mechanism.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 83-117 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract The polymerization dynamics of microtubules are central to their biological functions. Polymerization dynamics allow microtubules to adopt spatial arrangements that can change rapidly in response to cellular needs and, in some cases, to perform mechanical work. Microtubules utilize the energy of GTP hydrolysis to fuel a unique polymerization mechanism termed dynamic instability. In this review, we first describe progress toward understanding the mechanism of dynamic instability of pure tubulin and then discuss the function and regulation of microtubule dynamic instability in living cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 25-51 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract Mitochondria import most of their proteins from the cytosol. Dynamic protein complexes in the mitochondrial outer and inner membranes are responsible for the specific recognition and membrane translocation of preproteins. The preprotein translocase of the outer mitochondrial membrane contains several import receptors and a general import pore. The preprotein translocase of the inner membrane consists of a channel interacting with preproteins in transit and an import motor that includes the matrix heat shock protein Hsp70. Acidic patches of import components are thought to guide the import of positively charged signal sequences (acid chain hypothesis). Energy input is derived from the inner membrane potential and ATP. Proteins in the mitochondrial matrix are required for proteolytic processing and folding of imported proteins. The dynamic nature of the membrane translocase permits sorting of preproteins at distinct stages of the import pathway.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 119-146 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract Adherens junctions are specialized forms of cadherin-based adhesive contacts important for tissue organization in developing and adult organisms. Cadherins form protein complexes with cytoplasmic proteins (catenins) that convert the specific, homophilic-binding capacity of the extracellular domain into stable cell adhesion. The extracellular domains of cadherins form parallel dimers that possess intrinsic homophilic-binding activity. Cytoplasmic interactions can influence the function of the ectodomain by a number of potential mechanisms, including redistribution of binding sites into clusters, providing cytoskeletal anchorage, and mediating physiological regulation of cadherin function. Adherens junctions are likely to serve specific, specialized functions beyond the basic adhesive process. These functions include coupling cytoskeletal force generation to strongly adherent sites on the cell surface and the regulation of intracellular signaling events.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 147-170 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract The Drosophila ovary provides a favorable model system in which to study cellular morphogenesis. The development of a mature egg involves a syncytium of 16 germline cells and over 1000 somatically derived follicle cells. Intercellular transport, stable intercellular bridges, cell migrations, cell shape changes, and specific subcellular localization of many embryonic patterning determinants contribute to egg development and require a dynamic cytoskeleton. We discuss many of the recent genetic and cell biological studies that have led to insights into how the actin cytoskeleton is assembled and regulated during the morphogenesis of the Drosophila egg.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 333-361 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract Notch, LIN-12, and GLP-1 are receptors that mediate a broad range of cell interactions during Drosophila and nematode development. Signaling by these receptors relies on a conserved pathway with three core components: DSL ligand, LNG receptor, and a CSL effector that links the receptor to its transcriptional response. Although key functional regions have been identified in each class of proteins, the mechanism for signal transduction is not yet understood. Diverse regulatory mechanisms influence signaling by the LIN-12/Notch pathway. Inductive signaling relies on the synthesis of ligand and receptor in distinct but neighboring cells. By contrast, lateral signaling leads to the transformation of equivalent cells that express both ligand and receptor into nonequivalent cells that express either ligand or receptor. This transformation appears to rely on regulatory feedback loops within the LIN-12/Notch pathway. In addition, the pathway can be regulated by intrinsic factors that are asymmetrically segregated during cell division or by extrinsic cues via other signaling pathways. Specificity in the pathway does not appear to reside in the particular ligand or receptor used for a given cell-cell interaction. The existence of multiple ligands and receptors may have evolved from the stringent demands placed upon the regulation of genes encoding them.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 363-393 
    ISSN: 1081-0706
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Medicine
    Notes: Abstract Molecules involved in cell adhesion processes are often both structurally and functionally modular, with subdomains that are members of large protein families. Recently, high-resolution structures have been determined for representative members of many of these families including fragments of integrins, cadherins, fibronectin-like domains, and immunoglobulin-like domains. These structures have enhanced our understanding of cell adhesion processes at several levels. In almost all cases, ligand-binding sites have been visualized and provide insight into how these molecules mediate biologically important interactions. Metal-binding sites have been identified and characterized, allowing assessment of the role of bound ions in cell adhesion processes. Many of these structures serve as templates for modeling homologous domains in other proteins or, when the structure of a fragment consisting of more than one domain is determined, the structure of multidomain arrays of homologous domains. Knowledge of atomic structure also allows rational design of drugs that either mimic or target specific binding sites. In many cases, high-resolution structures have revealed unexpected relationships that pose questions about the evolutionary origin of specific domains. This review briefly describes several recently determined structures of cell adhesion molecules, summarizes some of the main results of each structure, and highlights common features of different systems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...