Now showing items 21-40 of 1164

    • Ambient Pyrite in Precambrian Chert: New Evidence and a Theory 

      Knoll, Andrew Herbert; Barghoorn, Elso S. (National Academy of Sciences, 1974)
      Ambient pyrites of two distinct types were described from middle Precambrian rocks of the Lake Superior area. A new class of this phenomenon is here described from middle Precambrian chert from western Australia. The newly ...
    • Anaerobic Methane Oxidation in Metalliferous Hydrothermal Sediments: Influence on Carbon Flux and Decoupling from Sulfate Reduction 

      Wankel, Scott D.; Adams, Melissa Marie; Johnston, David T; Hansel, Colleen; Joye, Samantha B.; Girguis, Peter R. (Wiley-Blackwell, 2012)
      The anaerobic oxidation of methane (AOM) is a globally significant sink that regulates methane flux from sediments into the oceans and atmosphere. Here we examine mesophilic to thermophilic AOM in hydrothermal sediments ...
    • Anaerobic Oxidation of Short-Chain Alkanes in Hydrothermal Sediments: Potential Influences on Sulfur Cycling and Microbial Diversity 

      Adams, Melissa Marie; Hoarfrost, Adrienne L.; Bose, Arpita; Joye, Samantha B.; Girguis, Peter R. (Frontiers Research Foundation, 2013)
      Short-chain alkanes play a substantial role in carbon and sulfur cycling at hydrocarbon-rich environments globally, yet few studies have examined the metabolism of ethane \((C_2)\), propane \((C_3)\), and butane \((C_4)\) ...
    • Analysis of Abrupt Transitions in Ecological Systems 

      Bestelmeyer, Brandon T.; Ellison, Aaron M.; Fraser, William R.; Gorman, Kristen B.; Holbrook, Sally J.; Laney, Christine M.; Ohman, Mark D.; Peters, Debra P. C.; Pillsbury, Finn C.; Rassweiler, Andrew; Schmitt, Russell J.; Sharma, Sapna (Ecological Society of America, 2011)
      The occurrence and causes of abrupt transitions, thresholds, or regime shifts between ecosystem states are of great concern and the likelihood of such transitions is increasing for many ecological systems. General understanding ...
    • Analytic Steady-state Space Use Patterns and Rapid Computations in Mechanistic Home Range Analysis 

      Barnett, Alex H.; Moorcroft, Paul (Springer Verlag, 2008)
      Mechanistic home range models are important tools in modeling animal dynamics in spatially complex environments. We introduce a class of stochastic models for animal movement in a habitat of varying preference. Such models ...
    • Analytic Webs Support the Synthesis of Ecological Data Sets 

      Ellison, Aaron M.; Osterweil, Leon; Hadley, Julian L.; Wise, Alexander; Boose, Emery Robert; Clarke, Lori; Foster, David Russell; Hanson, Allen; Jensen, David Michael; Kuzeja, Paul; Riseman, Edward; Schultz, Howard (Ecological Society of America, 2006)
      A wide variety of data sets produced by individual investigators are now synthesized to address ecological questions that span a range of spatial and temporal scales. It is important to facilitate such syntheses so that ...
    • Analytical Results for Individual and Group Selection of Any Intensity 

      Traulsen, Arne; Shoresh, Noam; Nowak, Martin A. (Springer Verlag, 2008)
      The idea of evolutionary game theory is to relate the payoff of a game to reproductive success (= fitness). An underlying assumption in most models is that fitness is a linear function of the payoff. For stochastic ...
    • Anatomical and Ecological Constraints on Phanerozoic Animal Diversity in the Marine Realm 

      Bambach, Richard; Knoll, Andrew; Sepkoski, J. John Jr (National Academy of Sciences, 2002)
      We grouped the fossil records of marine animal genera into suites defined by function and physiology, The stratigraphic coherence of the resulting diversity history indicates the importance of ecological structure in ...
    • An Anatomical Description of a Miniaturized Acorn Worm (Hemichordata, Enteropneusta) with Asexual Reproduction by Paratomy 

      Worsaae, Katrine; Sterrer, Wolfgang; Kaul-Strehlow, Sabrina; Hay-Schmidt, Anders; Giribet, Gonzalo (Public Library of Science, 2012)
      The interstitial environment of marine sandy bottoms is a nutrient-rich, sheltered habitat whilst at the same time also often a turbulent, space-limited, and ecologically challenging environment dominated by meiofauna. The ...
    • Anatomically modern Carboniferous harvestmen demonstrate early cladogenesis and stasis in Opiliones 

      Garwood, Russell J.; Dunlop, Jason A.; Giribet, Gonzalo; Sutton, Mark D. (Springer Nature, 2011)
      Harvestmen, the third most-diverse arachnid order, are an ancient group found on all continental landmasses, except Antarctica. However, a terrestrial mode of life and leathery, poorly mineralized exoskeleton makes ...
    • Ancestral Polymorphism of Mhc Class II Genes in Mice: Implications for Balancing Selection and the Mammalian Molecular Clock 

      Edwards, Scott; Chesnut, Kye; Satta, Yoko; Wakeland, Edward K. (Genetics Society of America, 1997)
      To investigate the evolutionary dynamics at Mhc class II DR genes of mice (genus Mus),we sequenced the peptide binding regions (PBRs) of 41 DRB (=E beta) genes and eight DRA (=E alpha) genes from 15 strains representing ...
    • Ancient and Recent Adaptive Evolution of Primate Non-Homologous End Joining Genes 

      Demogines, Ann; East, Alysia M.; Lee, Ji-Hoon; Grossman, Sharon Rachel; Sabeti, Pardis Christine; Paull, Tanya T.; Sawyer, Sara L. (Public Library of Science, 2010)
      In human cells, DNA double-strand breaks are repaired primarily by the non-homologous end joining (NHEJ) pathway. Given their critical nature, we expected NHEJ proteins to be evolutionarily conserved, with relatively little ...
    • Ancient Aqueous Environments at Endeavour Crater, Mars 

      Arvidson, R. E.; Squyres, S. W.; Bell, J. F.; Catalano, J. G.; Clark, B. C.; Crumpler, L. S.; de Souza, P. A.; Fairen, A. G.; Farrand, W. H.; Fox, V. K.; Gellert, R.; Ghosh, A.; Golombek, M. P.; Grotzinger, J. P.; Guinness, E. A.; Herkenhoff, K. E.; Jolliff, B. L.; Knoll, Andrew Herbert; Li, R.; McLennan, S. M.; Ming, D. W.; Mittlefehldt, D. W.; Moore, J. M.; Morris, R. V.; Murchie, S. L.; Parker, T. J.; Paulsen, G.; Rice, J. W.; Ruff, S. W.; Smith, M. D.; Wolff, M. J. (American Association for the Advancement of Science (AAAS), 2014)
      Opportunity has investigated in detail rocks on the rim of the Noachian age Endeavour crater, where orbital spectral reflectance signatures indicate the presence of Fe+3-rich smectites. The signatures are associated with ...
    • Ancient Impact and Aqueous Processes at Endeavour Crater, Mars 

      Knoll, Andrew Herbert; Squyres, S. W.; Arvidson, R. E.; Bell, J. F., III; Calef, F., III; Clark, B. C.; Cohen, B. A.; Crumpler, L. A.; de Souza, P. A., Jr.; Farrand, W. H.; Gellert, R.; Grant, J.; Hurowitz, J. A.; Herkenhoff, K. E.; Johnson, J. R.; Jolliff, B. L.; Li, R.; McLennan, S. M.; Ming, D. W.; Mittlefehldt, D. W.; Parker, T. J.; Paulsen, G.; Rice, M. S.; Ruff, S. W.; Schröder, C.; Yen, A. S.; Zacny, K. (American Association for the Advancement of Science, 2012)
      The rover Opportunity has investigated the rim of Endeavour Crater, a large ancient impact crater on Mars. Basaltic breccias produced by the impact form the rim deposits, with stratigraphy similar to that observed at ...
    • Ancient origin of placental expression in the growth hormone genes of anthropoid primates 

      Papper, Z.; Jameson, N. M.; Romero, R.; Weckle, A. L.; Mittal, P.; Benirschke, K.; Santolaya-Forgas, J.; Uddin, M.; Haig, David Addison; Goodman, M.; Wildman, D. E. (Proceedings of the National Academy of Sciences, 2009)
      In anthropoid primates, growth hormone (GH) genes have undergone at least 2 independent locus expansions, one in platyrrhines (New World monkeys) and another in catarrhines (Old World monkeys and apes). In catarrhines, the ...
    • Animals in a Bacterial World, A New Imperative for the Life Sciences 

      McFall-Ngai, M.; Hadfield, M. G.; Bosch, T. C. G.; Carey, H. V.; Domazet-Loso, T.; Douglas, A. E.; Dubilier, N.; Eberl, G.; Fukami, T.; Gilbert, S. F.; Hentschel, U.; King, N.; Kjelleberg, S.; Knoll, Andrew Herbert; Kremer, N.; Mazmanian, S. K.; Metcalf, J. L.; Nealson, K.; Pierce, Naomi E.; Rawls, J. F.; Reid, A.; Ruby, E. G.; Rumpho, M.; Sanders, Jon Gregory; Tautz, D.; Wernegreen, J. J. (Proceedings of the National Academy of Sciences, 2013)
      In the last two decades, the widespread application of genetic and genomic approaches has revealed a bacterial world astonishing in its ubiquity and diversity. This review examines how a growing knowledge of the vast range ...
    • An anisotropic-viscoplastic model of plant cell morphogenesis by tip growth 

      Dumais, Jacques; Shaw, Sidney L.; Steele, Charles R.; Long, Sharon R.; Ray, Peter M. (UPV/EHU Press, 2006)
      ABSTRACT Plant cell morphogenesis depends critically on two processes: the deposition of new wall material at the cell surface and the mechanical deformation of this material by the stresses resulting from the cell's turgor ...
    • The Anoles of Soroa: Aspects of Their Ecological Relationships 

      Rodriguez Schettino, Lourdes; Losos, Jonathan; Hertz, Paul E; de Queiroz, Kevin; Chamizo, Ada R; Leal, Manuel; Rivalta Gonzalez, Vilma (BioOne, 2010)
      Most lizard communities are characterized by having one or two dominant species and a handful of other species that occur at relatively low densities. However, Soroa, a site in the Sierra del Rosario of western Cuba, is ...
    • The Anolis Lizard Genome: An Amniote Genome without Isochores 

      Fujita, Matthew; Edwards, Scott V.; Ponting, Chris P. (Oxford University Press (OUP), 2011)
      Isochores are large regions of relatively homogeneous nucleotide composition and are present in the genomes of all mammals and birds that have been sequenced to date. The newly sequenced genome of Anolis carolinensis ...
    • Anomalous Carbonate Precipitates: Is the Precambrian the Key to the Permian? 

      Grotzinger, John P.; Knoll, Andrew (Society for Sedimentary Geology, 1995)
      Late Permian reefs of the Capitan complex, west Texas; the Magnesian Limestone, England; Chuenmuping reef, south China; and elsewhere contain anomalously large volumes of aragonite and calcite marine cements and seafloor ...