Search Results - (Author, Cooperation:S. Clegg)

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  1. 1
    C. R. Webster ; P. R. Mahaffy ; G. J. Flesch ; P. B. Niles ; J. H. Jones ; L. A. Leshin ; S. K. Atreya ; J. C. Stern ; L. E. Christensen ; T. Owen ; H. Franz ; R. O. Pepin ; A. Steele ; C. Achilles ; C. Agard ; J. A. Alves Verdasca ; R. Anderson ; D. Archer ; C. Armiens-Aparicio ; R. Arvidson ; E. Atlaskin ; A. Aubrey ; B. Baker ; M. Baker ; T. Balic-Zunic ; D. Baratoux ; J. Baroukh ; B. Barraclough ; K. Bean ; L. Beegle ; A. Behar ; J. Bell ; S. Bender ; M. Benna ; J. Bentz ; G. Berger ; J. Berger ; D. Berman ; D. Bish ; D. F. Blake ; J. J. Blanco Avalos ; D. Blaney ; J. Blank ; H. Blau ; L. Bleacher ; E. Boehm ; O. Botta ; S. Bottcher ; T. Boucher ; H. Bower ; N. Boyd ; B. Boynton ; E. Breves ; J. Bridges ; N. Bridges ; W. Brinckerhoff ; D. Brinza ; T. Bristow ; C. Brunet ; A. Brunner ; W. Brunner ; A. Buch ; M. Bullock ; S. Burmeister ; M. Cabane ; F. Calef ; J. Cameron ; J. Campbell ; B. Cantor ; M. Caplinger ; J. Caride Rodriguez ; M. Carmosino ; I. Carrasco Blazquez ; A. Charpentier ; S. Chipera ; D. Choi ; B. Clark ; S. Clegg ; T. Cleghorn ; E. Cloutis ; G. Cody ; P. Coll ; P. Conrad ; D. Coscia ; A. Cousin ; D. Cremers ; J. Crisp ; A. Cros ; F. Cucinotta ; C. d'Uston ; S. Davis ; M. Day ; M. de la Torre Juarez ; L. DeFlores ; D. DeLapp ; J. DeMarines ; D. DesMarais ; W. Dietrich ; R. Dingler ; C. Donny ; B. Downs ; D. Drake ; G. Dromart ; A. Dupont ; B. Duston ; J. Dworkin ; M. D. Dyar ; L. Edgar ; K. Edgett ; C. Edwards ; L. Edwards ; B. Ehlmann ; B. Ehresmann ; J. Eigenbrode ; B. Elliott ; H. Elliott ; R. Ewing ; C. Fabre ; A. Fairen ; K. Farley ; J. Farmer ; C. Fassett ; L. Favot ; D. Fay ; F. Fedosov ; J. Feldman ; S. Feldman ; M. Fisk ; M. Fitzgibbon ; M. Floyd ; L. Fluckiger ; O. Forni ; A. Fraeman ; R. Francis ; P. Francois ; C. Freissinet ; K. L. French ; J. Frydenvang ; A. Gaboriaud ; M. Gailhanou ; J. Garvin ; O. Gasnault ; C. Geffroy ; R. Gellert ; M. Genzer ; D. Glavin ; A. Godber ; F. Goesmann ; W. Goetz ; D. Golovin ; F. Gomez Gomez ; J. Gomez-Elvira ; B. Gondet ; S. Gordon ; S. Gorevan ; J. Grant ; J. Griffes ; D. Grinspoon ; J. Grotzinger ; P. Guillemot ; J. Guo ; S. Gupta ; S. Guzewich ; R. Haberle ; D. Halleaux ; B. Hallet ; V. Hamilton ; C. Hardgrove ; D. Harker ; D. Harpold ; A. M. Harri ; K. Harshman ; D. Hassler ; H. Haukka ; A. Hayes ; K. Herkenhoff ; P. Herrera ; S. Hettrich ; E. Heydari ; V. Hipkin ; T. Hoehler ; J. Hollingsworth ; J. Hudgins ; W. Huntress ; J. Hurowitz ; S. Hviid ; K. Iagnemma ; S. Indyk ; G. Israel ; R. Jackson ; S. Jacob ; B. Jakosky ; E. Jensen ; J. K. Jensen ; J. Johnson ; M. Johnson ; S. Johnstone ; A. Jones ; J. Joseph ; I. Jun ; L. Kah ; H. Kahanpaa ; M. Kahre ; N. Karpushkina ; W. Kasprzak ; J. Kauhanen ; L. Keely ; O. Kemppinen ; D. Keymeulen ; M. H. Kim ; K. Kinch ; P. King ; L. Kirkland ; G. Kocurek ; A. Koefoed ; J. Kohler ; O. Kortmann ; A. Kozyrev ; J. Krezoski ; D. Krysak ; R. Kuzmin ; J. L. Lacour ; V. Lafaille ; Y. Langevin ; N. Lanza ; J. Lasue ; S. Le Mouelic ; E. M. Lee ; Q. M. Lee ; D. Lees ; M. Lefavor ; M. Lemmon ; A. Lepinette Malvitte ; R. Leveille ; E. Lewin-Carpintier ; K. Lewis ; S. Li ; L. Lipkaman ; C. Little ; M. Litvak ; E. Lorigny ; G. Lugmair ; A. Lundberg ; E. Lyness ; M. Madsen ; J. Maki ; A. Malakhov ; C. Malespin ; M. Malin ; N. Mangold ; G. Manhes ; H. Manning ; G. Marchand ; M. Marin Jimenez ; C. Martin Garcia ; D. Martin ; M. Martin ; J. Martinez-Frias ; J. Martin-Soler ; F. J. Martin-Torres ; P. Mauchien ; S. Maurice ; A. McAdam ; E. McCartney ; T. McConnochie ; E. McCullough ; I. McEwan ; C. McKay ; S. McLennan ; S. McNair ; N. Melikechi ; P. Y. Meslin ; M. Meyer ; A. Mezzacappa ; H. Miller ; K. Miller ; R. Milliken ; D. Ming ; M. Minitti ; M. Mischna ; I. Mitrofanov ; J. Moersch ; M. Mokrousov ; A. Molina Jurado ; J. Moores ; L. Mora-Sotomayor ; J. M. Morookian ; R. Morris ; S. Morrison ; R. Mueller-Mellin ; J. P. Muller ; G. Munoz Caro ; M. Nachon ; S. Navarro Lopez ; R. Navarro-Gonzalez ; K. Nealson ; A. Nefian ; T. Nelson ; M. Newcombe ; C. Newman ; H. Newsom ; S. Nikiforov ; B. Nixon ; E. Noe Dobrea ; T. Nolan ; D. Oehler ; A. Ollila ; T. Olson ; M. A. de Pablo Hernandez ; A. Paillet ; E. Pallier ; M. Palucis ; T. Parker ; Y. Parot ; K. Patel ; M. Paton ; G. Paulsen ; A. Pavlov ; B. Pavri ; V. Peinado-Gonzalez ; L. Peret ; R. Perez ; G. Perrett ; J. Peterson ; C. Pilorget ; P. Pinet ; J. Pla-Garcia ; I. Plante ; F. Poitrasson ; J. Polkko ; R. Popa ; L. Posiolova ; A. Posner ; I. Pradler ; B. Prats ; V. Prokhorov ; S. W. Purdy ; E. Raaen ; L. Radziemski ; S. Rafkin ; M. Ramos ; E. Rampe ; F. Raulin ; M. Ravine ; G. Reitz ; N. Renno ; M. Rice ; M. Richardson ; F. Robert ; K. Robertson ; J. A. Rodriguez Manfredi ; J. J. Romeral-Planello ; S. Rowland ; D. Rubin ; M. Saccoccio ; A. Salamon ; J. Sandoval ; A. Sanin ; S. A. Sans Fuentes ; L. Saper ; P. Sarrazin ; V. Sautter ; H. Savijarvi ; J. Schieber ; M. Schmidt ; W. Schmidt ; D. Scholes ; M. Schoppers ; S. Schroder ; S. Schwenzer ; E. Sebastian Martinez ; A. Sengstacken ; R. Shterts ; K. Siebach ; T. Siili ; J. Simmonds ; J. B. Sirven ; S. Slavney ; R. Sletten ; M. Smith ; P. Sobron Sanchez ; N. Spanovich ; J. Spray ; S. Squyres ; K. Stack ; F. Stalport ; T. Stein ; N. Stewart ; S. L. Stipp ; K. Stoiber ; E. Stolper ; B. Sucharski ; R. Sullivan ; R. Summons ; D. Sumner ; V. Sun ; K. Supulver ; B. Sutter ; C. Szopa ; F. Tan ; C. Tate ; S. Teinturier ; I. ten Kate ; P. Thomas ; L. Thompson ; R. Tokar ; M. Toplis ; J. Torres Redondo ; M. Trainer ; A. Treiman ; V. Tretyakov ; R. Urqui-O'Callaghan ; J. Van Beek ; T. Van Beek ; S. VanBommel ; D. Vaniman ; A. Varenikov ; A. Vasavada ; P. Vasconcelos ; E. Vicenzi ; A. Vostrukhin ; M. Voytek ; M. Wadhwa ; J. Ward ; E. Weigle ; D. Wellington ; F. Westall ; R. C. Wiens ; M. B. Wilhelm ; A. Williams ; J. Williams ; R. Williams ; R. B. Williams ; M. Wilson ; R. Wimmer-Schweingruber ; M. Wolff ; M. Wong ; J. Wray ; M. Wu ; C. Yana ; A. Yen ; A. Yingst ; C. Zeitlin ; R. Zimdar ; M. P. Zorzano Mier
    American Association for the Advancement of Science (AAAS)
    Published 2013
    Staff View
    Publication Date:
    2013-07-23
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Published by:
    http://www.aaas.org/

    Latest Papers from Table of Contents or Articles in Press
  2. 2
    S. M. McLennan ; R. B. Anderson ; J. F. Bell, 3rd ; J. C. Bridges ; F. Calef, 3rd ; J. L. Campbell ; B. C. Clark ; S. Clegg ; P. Conrad ; A. Cousin ; D. J. Des Marais ; G. Dromart ; M. D. Dyar ; L. A. Edgar ; B. L. Ehlmann ; C. Fabre ; O. Forni ; O. Gasnault ; R. Gellert ; S. Gordon ; J. A. Grant ; J. P. Grotzinger ; S. Gupta ; K. E. Herkenhoff ; J. A. Hurowitz ; P. L. King ; S. Le Mouelic ; L. A. Leshin ; R. Leveille ; K. W. Lewis ; N. Mangold ; S. Maurice ; D. W. Ming ; R. V. Morris ; M. Nachon ; H. E. Newsom ; A. M. Ollila ; G. M. Perrett ; M. S. Rice ; M. E. Schmidt ; S. P. Schwenzer ; K. Stack ; E. M. Stolper ; D. Y. Sumner ; A. H. Treiman ; S. VanBommel ; D. T. Vaniman ; A. Vasavada ; R. C. Wiens ; R. A. Yingst
    American Association for the Advancement of Science (AAAS)
    Published 2013
    Staff View
    Publication Date:
    2013-12-11
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Bays ; Calcium Sulfate/analysis/chemistry ; Chlorine/analysis/chemistry ; *Exobiology ; Extraterrestrial Environment/*chemistry ; Ferrosoferric Oxide/analysis/chemistry ; Geologic Sediments/*chemistry ; Halogens/analysis/chemistry ; Hydrogen-Ion Concentration ; Iron/analysis/chemistry ; Magnesium/analysis/chemistry ; *Mars ; Silicates/analysis/chemistry ; Water/chemistry
    Published by:
    http://www.aaas.org/

    Latest Papers from Table of Contents or Articles in Press
  3. 3
    T. Coulson ; S. Clegg
    Nature Publishing Group (NPG)
    Published 2014
    Staff View
    Publication Date:
    2014-07-25
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Animals ; *Climate Change ; Female ; Fur Seals/*genetics ; *Heterozygote
    Published by:
    http://www.nature.com/

    Latest Papers from Table of Contents or Articles in Press
  4. 4
    Staff View
    Publication Date:
    2018-01-26
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Geosciences
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Ecology, Evolution
    Published by:
    http://www.aaas.org/

    Latest Papers from Table of Contents or Articles in Press
  5. 5
    Clegg, S. J. ; Greenough, R. D. ; Hagston, W. E.

    [S.l.] : American Institute of Physics (AIP)
    Published 1993
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The temperature dependences of the magnetization and magnetostriction have been measured in Tbx(Fe82B18)100−x, Smx(Fe82B18)100−x, and TbxLa5(Fe82B18)95−x, where 0≤x≤50. Below a spin freezing temperature Tf, which depends on the rare earth (RE) content, a random anisotropy phase is established when the anisotropy to exchange ratio is large. Between Tf and the Curie temperature Tc, the temperature dependences of the magnetostrictive contributions from the rare earth ions are compared with the theoretical single ion and two ions predictions. For low Tb concentrations (∼10 at. %) or larger Tb content (∼30 at. %) with small additions of La, the data follow the Iˆ9/2(x) power law whereas the Iˆ5/2(x) is otherwise more appropriate. For Sm, when x∼50, single ion Iˆ5/2(x) behavior is seen but with x∼10, a two ion (M/M0)2 dependence is observed. These different temperature dependences are a reflection of the symmetry of the fields surrounding the RE ions and provide useful information for the modeling of RE ions in an amorphous matrix.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.353660

    Articles: DFG German National Licenses
  6. 6
    Greenough, R. D. ; Gregory, T. J. ; Clegg, S. J. ; Purdy, J. H.

    [S.l.] : American Institute of Physics (AIP)
    Published 1991
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The effects of additions of the rare earths (RE) terbium and samarium on the room temperature magnetoelastic properties of amorphous Fe0.82B0.18 and Fe0.90Zr0.10 have been studied for up to 50 and 10 at. % RE, respectively. As the RE content in the Fe–Zr compounds is raised, the relative permeability increases, as do the Curie temperature, magnetostriction and magnetomechanical coupling. The magnetic phase diagram forFe–Zr–RE derived from magnetization data indicates the transition to a random anisotropy phase, evident at low temperatures in Fe0.90Zr0.10, rapidly rises to near room temperature with the addition of Tb and approaches the Curie temperature near ∼9 at. % Tb. This pattern of behavior is not seen in the Fe–B–RE compounds in which the exchange dominated behavior at room temperature remains essentially unchanged and is accompanied by reductions in permeability and magnetostriction until more than ∼18 at. % RE is included.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.349898

    Articles: DFG German National Licenses
  7. 7
    Clegg, S. J. ; Purdy, J. H. ; Greenough, R. D. ; Jerems, F.

    [S.l.] : American Institute of Physics (AIP)
    Published 1994
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The addition of Tb to melt spun iron-boron or iron-zirconium compounds raises the magneto- striction to practically useful levels (≥450 ppm) at room temperature. The present work examines the corresponding compositional and temperature dependencies of the magnetization in Tbx (Fe0.82B0.18)1−x for 0≤x≤0.5 and Tb y (Fe0.90Zr0.10)1−y for 0≤y≤0.1. Increasing the Tb content in Fe-B compounds decreases the room-temperature magnetization towards a compensation point and lowers the Curie temperature Tc. In Fe-Zr compounds, Tb increases the room-temperature magnetization and raises Tc. Magnetic phase diagrams are presented for each group of compounds and exchange frustration effects identified by comparing the observed temperature dependencies of the reduced magnetization with predictions from the Handrich mean field model. Only 3 at. % Tb in Fe-Zr is sufficient to annul exchange fluctuations, but in Fe-B compounds exchange frustration persists throughout the compositional range.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.358270

    Articles: DFG German National Licenses
  8. 8
    Tarkkanen, A.-M. ; Allen, B. L. ; Westerlund, B. ; Holthöfer, H. ; Kuusela, P. ; Risteli, L. ; Clegg, S. ; Korhonen, T. K.

    Oxford, UK : Blackwell Publishing Ltd
    Published 1990
    Staff View
    ISSN:
    1365-2958
    Source:
    Blackwell Publishing Journal Backfiles 1879-2005
    Topics:
    Biology
    Medicine
    Notes:
    Tissue-binding specificity of the type-3 fimbriae of pathogenic enteric bacteria was determined using frozen sections of human kidney. A wild-type Kleb-siella sp. strain and the recombinant strain Escherichia coli HB101(pFK12), both expressing type-3 fimbriae, as well as the purified type-3 fimbriae effectively bound to sites at or adjacent to tubular basement membranes, Bowman's capsule, arterial walls, and the interstitial connective tissue. Bacterial adherence to kidney was decreased after collagenase treatment of the tissue sections. Recombinant strains expressing type-3 fimbriae specifically adhered to type V collagen immobilized on glass slides, whereas other collagens, fibronectin or laminin did not support bacterial adherence. In accordance with these findings, specific binding of purified type-3 fimbriae to immobilized type V collagen was demonstrated. Specific adhesion to type V collagen was also seen with the recombinant strain HB101(pFK52/pDC17), which expresses the mrkD gene of the type-3 fimbrial gene cluster in association with the pap-encoded fimbrial filament of E. coli, showing that the observed binding was mediated by the minor lectin (MrkD) protein of the type-3 fimbrial filament. The interaction is highly dependent on the conformation of type V collagen molecules since type V collagen in solution did not react with the fimbriae. Specific binding to type V collagen was also exhibited by type-3 fimbriae strains of Yeisinia and Salmonella, showing that the ability to use type collagen as tissue target is widespread among enteric bacteria.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1111/j.1365-2958.1990.tb00714.x

    Articles: DFG German National Licenses
  9. 9
    Nichols, W. A. ; Clegg, S. ; Brown, M. R.

    Oxford, UK : Blackwell Publishing Ltd
    Published 1990
    Staff View
    ISSN:
    1365-2958
    Source:
    Blackwell Publishing Journal Backfiles 1879-2005
    Topics:
    Biology
    Medicine
    Notes:
    The nucleotide sequence of a DNA fragment that contains the fimA gene, encoding the major fimbrial subunit, of Serratia marcescens IA506 and associated flanking sequences has been elucidated. In addition, the origin of transcription has been identified and is located 120 base pairs upstream of the fimA initiation codon. The predicted amino acid sequence of the FimA polypeptide exhibits some degree of sequence homology with the fimbrial subunits encoded by the fimA determinants of Klebsiella pneumoniae, Salmonella typhimurium, and Escherichia coli and also to Smf2, the major structural component of mannose-resistant (MR) fimbriae of S. marcescens. The Serratia adhesin that facilitates haemagglutination mediated by type 1 fimbriae is less susceptible to inhibition by D-mannose than has been observed to be the case in other type 1 fimbrial adhesins. The molecule conferring this adherence specificity has been shown to be distinct from the fimA gene product and, therefore, is analogous to the fimbrial systems reported in other species.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1111/j.1365-2958.1990.tb00573.x

    Articles: DFG German National Licenses
  10. 10
    Staff View
    ISSN:
    1476-4687
    Source:
    Nature Archives 1869 - 2009
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Notes:
    [Auszug] We constructed maps for eight chromosomes (1, 6, 9, 10, 13, 20, X and (previously) 22), representing one-third of the genome, by building landmark maps, isolating bacterial clones and assembling contigs. By this approach, we could establish the long-range organization of the maps early in the ...
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1038/35057165

    Articles: DFG German National Licenses
  11. 11
    Staff View
    ISSN:
    1476-4687
    Source:
    Nature Archives 1869 - 2009
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Notes:
    [Auszug] We have placed 7,600 cytogenetically defined landmarks on the draft sequence of the human genome to help with the characterization of genes altered by gross chromosomal aberrations that cause human disease. The landmarks are large-insert clones mapped to chromosome bands by fluorescence in situ ...
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1038/409953a0

    Articles: DFG German National Licenses
  12. 12
    Gerlach, G.-F. ; Clegg, S.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0378-1119
    Keywords:
    Hemagglutination ; epitopes ; expression in Escherichia coli ; fimbrial subunit ; genomic library ; nucleotide sequence ; recombinant DNA ; uropathogenic
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Biology
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/0378-1119(88)90338-1

    Articles: DFG German National Licenses
  13. 13
    Whalley, E. T. ; Clegg, S. ; Stewart, J. M. ; Vavrek, R. J.
    Springer
    Published 1987
    Staff View
    ISSN:
    1432-1912
    Keywords:
    Pain ; Kinins ; Receptor ; Inflammation
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Medicine
    Notes:
    Summary 1. The effect of bradykinin (BK) and some analogues of BK on the human blister base was studied. 2. BK produced reproducible dose-related increases in pain responses. A characteristic delay, which was not dose-related occurred between application of BK and the resultant response. 3. The rank order of potency of several kinin analogues on the pain response was BK 〉 〉 〉 Σ-cyclo-(Lys1-Gly6)-BK = Σ-cyclo-kallidin 〉 des-Arg9-BK. 4. No increase in pain response was seen with repeated application of the selective B1 receptor agonist des-Arg9-BK to the same blister base at 4 h intervals. The B1 receptor antagonist des-Arg9-Leu8-BK was without effect against BK-induced responses. 5. The B2 receptor antagonists, d-Arg-Arg-Pro-Hyp-Gly-Thi-Ser-d-Phe-Thi-Arg-TFA and d-Pro-Phe-Arg-heptylamide produced significant antagonism of the bradykinin-induced pain responses at doses which had no effect against 5-hydroxytryptamine or potassium chloride. 6. It is concluded that the kinin receptor mediating pain on the human blister base is of the B2 type.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00165756

    Articles: DFG German National Licenses
  14. 14
    Clegg, S. ; Gobran, G. R.
    Springer
    Published 1995
    Staff View
    ISSN:
    1573-5036
    Keywords:
    aluminium toxicity ; phosphorus deficiency ; nitrogen saturation ; 32P bioassay
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes:
    Abstract The impact of two constant non-toxic levels of Al stress (0.2 and 0.4 mM) on growth and 32P uptake capacity on sub-optimal (P-limited) Betula pendula seedlings grown in sand culture was examined. Seedling growth was under optimum controlled conditions in a growth chamber where nutrient additions were made at a predetermined relative addition rate (RA) of 10% day-1. Three treatment groups of seedlings 0, 0.2 and 0.4 mM Al were harvested at 15, 29 and 42 days. The excised roots were exposed to a 32P-labelled solution for 15 minutes to measure their capacity for P uptake. Growth was determined by weighing the roots, stems and leaves of the seedlings. Growth data showed that relative growth rate (RG) should equal the RA of P the most limiting nutrient, which was supplied at P/N 3% instead of an optimal 15%. Therefore, Ingestad's theory can also be used succesfully in sand culture and this may be particularly important for future studies of root and rhizosphere exudates. Low levels of Al (〈 0.2 mM) in combination with low P supply significantly lowered the RG of the birch seedlings by further reducing P supply. However, previous studies of birch seedling growth and nutrient uptake using Ingestad's solution culture technique with optimumal P supply did not show any effect of Al on growth untill the Al was in excess of 3 mM. Aluminium was not directly toxic to the plants and therefore roots could respond to the 32P bioassay.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00029326

    Articles: DFG German National Licenses
  15. 15
    Gobran, G.R. ; Clegg, S. ; Courchesne, F.
    Springer
    Published 1998
    Staff View
    ISSN:
    1573-515X
    Keywords:
    acidity ; ecosystem perturbation ; fine roots ; forest soils ; modeling ; mycorrhizae ; nutrient acquisition ; rhizosphere ; soil sampling ; weathering
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Chemistry and Pharmacology
    Geosciences
    Notes:
    Abstract In the rhizosphere, biotic and abiotic processes interact to create a zone distinct from the bulk soil that may strongly influence the biogeochemistry of forest ecosystems. This paper presents a conceptual model based upon three operationally defined soil-root compartments (bulk soil, rhizosphere and soil-root interface) to assess nutrient availability in the mineral soil-root system. The model is supported by chemical and mineralogical analyses from bulk and rhizosphere soils collected from a Norway spruce forest. The rhizosphere was more intensively weathered and had accumulated more acidity, base cations and phosphorus than the bulk soil. The quantity and quality of organic matter regulate the reciprocal relationships between soil and roots with their associated biota. However, the biogeochemical role of organic matter in the rhizosphere still remains as an area in which more future research is needed. The mechanisms that may regulate nutrient availability in the rhizosphere are also discussed and related to nutrient cycling and adaptation of forests growing under nutrient poor or perturbed conditions. We suggest that the rhizosphere is not an ephemeral environment in the soil, but persists over time and is resilient against perturbation as evinced by consistent differences between rhizosphere and bulk chemistry and mineralogy over wide range of field treatments.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1023/A:1005967203053

    Articles: DFG German National Licenses
  16. 16
    Staff View
    ISSN:
    1573-0662
    Keywords:
    Hypochlorous acid ; Henry's law ; stratospheric aerosol ; solubility
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Chemistry and Pharmacology
    Geosciences
    Notes:
    Abstract Henry's law constants K′H (mol kg−1 atm−1) for the reaction HOCl(g)=HOCl(aq) near room temperature, literature data for the associated enthalpy change, and solubilities of HOCl in aqueous H2SO4 (46 to 60 wt%) at temperatures relevant to the stratosphere (200 K≤T≤230 K) are shown to be thermodynamically consistent. Effective Henry's law constants [H*=mHOCl/pHOCl, in mol kg−1 atm−1] of HOCl in aqueous H2SO4 are given by: ln(H*)=6.4946−mH2SO4(−0.04107+54.56/T)−5862 (1/To−1/T) where T(K) is temperature and To=298.15K. The activity coefficient of HOCl in aqueous H2SO4 has a simple Setchenow-type dependence upon H2SO4 molality.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00712439

    Articles: DFG German National Licenses
  17. 17
    Khan, I. ; Brimblecombe, P. ; Clegg, S. L.
    Springer
    Published 1995
    Staff View
    ISSN:
    1573-0662
    Keywords:
    Henry's law ; solubility ; removal ; salt effect ; formic acid ; acetic acid ; propionic acid ; n-butyric acid ; isobutyric acid ; n-valeric acid ; isovaleric acid ; neovaleric acid ; n-caproic acid ; pyruvic acid
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Chemistry and Pharmacology
    Geosciences
    Notes:
    Abstract Henry's law constantsK′ H (mol kg−1 atm−1) have been determined at 298.15 K for the following organic acids: formic acid (5.53±0.27×103); acetic acid (5.50±0.29×103); propionic acid (5.71±0.34×103);n-butyric acid (4.73±0.18×103); isobutyric acid (1.13±0.12×103); isovaleric acid (1.20±0.11×103) and neovaleric acid (0.353±0.04×103). They have also been determined fromT=278.15 K toT=308.15 K forn-valeric acid (ln(K′ H)=−14.3371+6582.96/T);n-caproic acid (ln(K′ H)=−13.9424+6303.73/T) and pyruvic acid (ln(K′ H)=−4.41706+5087.92/T). The influence of 9 salts on the solubility of pyruvic acid at 298.15 K has been measured. Pyruvic acid is soluble enough to partition strongly into aqueous atmospheric aerosols. Other acids require around 1 g of liquid water m−3 (typical of clouds) to partition significantly into the aqueous phase. The degree of partitioning is sensitive to temperature. Considering solubility and dissociation (to formate) alone, the ratio of formic acid to acetic acid in liquid water in the atmosphere (at equilibrium with the gas phase acids) is expected to increase with rising pH, but show little variation with temperature.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00696639

    Articles: DFG German National Licenses
  18. 18
    Brimblecombe, P. ; Clegg, S. L.
    Springer
    Published 1988
    Staff View
    ISSN:
    1573-0662
    Keywords:
    Hydrobromic acid ; hydrochloric acid ; hydrofluoric acid ; hydro-iodic acid ; nitric acid ; methanesulphonic acid ; solubility ; Henry's law ; seasalt ; aerosol ; degassing ; activity coefficient ; Pitzer model ; fluoride depletion
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Chemistry and Pharmacology
    Geosciences
    Notes:
    Abstract The following Henry's law constants (K H/mol2kg-2atm-1) for HNO3 and the hydrohalic acids have been evaluated from available partial pressure and other thermodynamic data from 0°–40°C, 1 atm total pressure: HNO 3 , 40°C–5.85×105; 30°C–1.50×106; 25°C–2.45×106; 20°C–4.04×106; 10°C–1.15×107; 0°C–3.41×107. HF, 40°C–3.2; 30°C–6.6; 25°C–9.61; 20°C–14.0; 10°C–32.0; 0°C–76. HCl, 40°C–4.66×105; 30°C–1.23×106; 25°C–2.04×106; 20°C–3.37×106; 10°C–9.71×106; 0°C–2.95×107. HBr, 40°C–2.5×108; 30°C–7.5×108; 25°C–1.32×109; 20°C–2.37×109; 10°C–8.10×109; 0°C–3.0×1010. HI, 40°C–5.2×108; 30°C–1.5×109; 25°C–2.5×109; 20°C–4.5×109; 10°C–1.5×1010; 0°C–5.0×1010. Simple equilibrium models suggest that HNO3, CH3SO3H and other acids up to 10x less soluble than HCl displace it from marine seasalt aerosols. HF is displaced preferentially to HCl by dissolved acidity at all relative humidities greater than about 80%, and should be entirely depleted in aged marine aerosols.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00048251

    Articles: DFG German National Licenses
  19. 19
    Bowden, D. J. ; Clegg, S. L. ; Brimblecombe, P.
    Springer
    Published 1998
    Staff View
    ISSN:
    1573-0662
    Keywords:
    Henry's law ; solubility ; aerosol ; fluoroacetic acid ; chloroacetic acid ; bromoacetic acid ; difluoroacetic acid ; dichloroacetic acid ; dibromoacetic acid ; trifluoroacetic acid ; trichloroacetic acid ; tribromoacetic acid ; chloro-difluoroacetic acid
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Chemistry and Pharmacology
    Geosciences
    Notes:
    Abstract Henry's law constants K′H (mol kg-1 atm-1) have been measured between 278.15 K and 308.15 K for the following organic acids: CH2FCOOH (ln(K′H[298.15 K]) = 11.3 ± 0.2), CH2ClCOOH (11.59 ± 0.14), CH2BrCOOH (11.94 ± 0.21), CHF2COOH (10.32 ± 0.10), CHCl2COOH (11.69 ± 0.11), CHBr2COOH (12.33 ± 0.29), CBr3COOH (12.61 ± 0.21), and CClF2COOH (10.11 ± 0.12). The variation of K′H with temperature was determined for all acids except CH2FCOOH and CBr3COOH, with Δr H° for the dissolution reaction ranging from −85.2 ± 2.6 to −57.1 ± 2.5 kJ mol-1, meaning that their solubility is generally more sensitive to temperature than is the case for the simple carboxylic acids. The Henry's law constants show consistent trends with halogen substitution and, together with their high solubility compared to the parent (acetic) acid (ln(K′H[298.15 K]) = 8.61), present a severe test of current predictive models based upon molecular structure. The solubility of haloacetic acids and strong dissociation at normal pH mean that they will partition almost entirely into cloud and fog in the atmosphere (0.05–1.0 g H2O m-3), but can reside in both phases for the liquid water contents typical of aerosols (10-5-10-4 g H2O m-3).
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1023/A:1005899813756

    Articles: DFG German National Licenses