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  • 2000-2004  (5)
  • 1980-1984  (2)
  • 1975-1979  (3)
  • 1970-1974  (3)
  • 1965-1969  (2)
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  • 1
    Electronic Resource
    Electronic Resource
    A canopy photosynthesis model to predict the dry matter production of cocksfoot pastures under varying temperature, nitrogen and water regimes (2003)
    Oxford, UK : Blackwell Science Ltd
    Grass and forage science 58 (2003), S. 0 
    Details
    ISSN: 1365-2494
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Daily net canopy photosynthesis (Pn) of cocksfoot (Dactylis glomerata L.) was predicted for combinations of temperature, herbage nitrogen (N) concentration and water status from the integration of models of leaf photosynthesis of the light-saturated photosynthetic rate (Pmax), photosynthetic efficiency (α) and the degree of curvature (θ) of leaf light-response curves. The effect on Pn, maximum Pn (Pn max) and the optimum leaf area index (LAI at Pn max) was examined when any one of these factors was limiting. The ranges that gave the optimum values of Pn (Pn max = 30·8–33·5 g CO2m−2 d−1) for temperature (19–22°C) and N concentration (40–50 g N kg−1 DM) were smaller than those for net leaf photosynthesis. Also, Pn fell to 0 at a lower level of water stress (pre-dawn leaf water potential, ψlp = −12·5 bar) than for Pmax. The canopy photosynthesis model was then used to compare predicted and measured dry matter (DM) production for cocksfoot pastures grown under a diverse range of environmental conditions with field data from New Zealand and Argentina. To predict DM production leaf area index and leaf canopy angle were included from field measurements. The model explained about 0·85 of the variation in cocksfoot DM production for the range of 6·5–134 kg DM ha−1 d−1. The canopy model overestimated the DM production by 0·10 which indicates that a further Pmax function for leaves of different ages and a partitioning sub-model may be needed to improve predictions of DM production.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2494.2003.00395.x
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  • 2
    Electronic Resource
    Electronic Resource
    Net photosynthetic rate of cocksfoot leaves under continuous and fluctuating shade conditions in the field (2002)
    Oxford, UK : Blackwell Science Ltd
    Grass and forage science 57 (2002), S. 0 
    Details
    ISSN: 1365-2494
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Maximum light-saturated photosynthetic rate (Pmax) and stomatal conductance (gs) of field-grown cocksfoot (Dactylis glomerata L.) leaves in a silvopastoral system were measured at different times under moderate (850–950 µmol m−2 s−1 photosynthetic photon flux density, PPFD) and severe shade (85–95 µmol m−2 s−1 PPFD). Also Pmax and gs were measured after 30, 60 and 180 min of severe shade to determine the lag in the rise of photosynthesis rate from low to high irradiance levels (induction state). The highest Pmax and gs values obtained were 26·5 µmol CO2 m−2 s−1 and 0·41 mol H2O m−2 s−1 in non-limiting conditions with full sunlight (1900 µmol m−2 s−1 PPFD). These values were defined as standardized dimensionless Pmaxs=1 and gss=1 for comparison of treatment effects. The Pmaxs under severe shade decreased by 0·004 units per minute from 1 to 180 min and reached a steady-state of 0·37 units after 140 min. Under moderate shade, Pmaxs decreased by 0·002 units per minute from 1 to 120 min and reached a steady-state of 0·76 units. The time required to reach full induction on return to full sun (Pmaxs=1) was 15 min after 30 min of severe shade and 37 min after 180 min of shade. Mathematical equations were derived to describe the changes in Pmaxs and gss under severe and moderate shade and during induction. The rate of change of gss was slower than for Pmaxs on entering shade and also slower during the subsequent induction process. This indicated other factors in addition to gs were operating in the reduction and increment of Pmax and a two-step model to explain this is proposed. The defined photosynthetic responses of cocksfoot leaves to fluctuating light regimes could be used to develop quantitative predictions of Pmax for inclusion in a canopy photosynthesis model of silvopastoral systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2494.2002.00312.x
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  • 3
    Electronic Resource
    Electronic Resource
    Modelling net photosynthetic rate of field-grown cocksfoot leaves under different nitrogen, water and temperature regimes (2002)
    Oxford UK : Blackwell Science Ltd
    Grass and forage science 57 (2002), S. 0 
    Details
    ISSN: 1365-2494
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: A simple multiplicative model using temperature, foliage nitrogen (N) concentration and water status was developed to predict the maximum photosynthetic rate (Pmax) of field-grown cocksfoot (Dactylis glomerata L.) leaves when none, one, two or all the factors were limiting. The highest Pmax was 27·4 μmol CO2 m–2 s−1 in non-limited conditions, which was defined as the standardized Pmax value dimensionless (Pmaxs=1). Pmaxs increased 0·058 units per °C from 10°C to the optimum range (19–23°C) (Pmaxs=1) and then declined 0·077 units of Pmaxs per °C from 23 to 31°C. Pmaxs=1 was also measured from 59 to 52 g N kg−1 dry matter (DM) foliage N. Pmaxs then decreased at the rate of 0·115 units per 10 g N kg−1 DM from 52 to 26 g N kg−1 DM, and 0·409 units of Pmaxs per 10 g N kg−1 DM from 26 to 15 g N kg−1 DM. For predawn leaf water potential (ψlp), Pmaxs=1 was measured from −0·1 to −1·2 bar but declined linearly at a rate of 0·078 units per bar of ψlp from −1·2 to −14·0 bar because of a linear decrease in stomatal conductance. An interaction between low N content (≤20 g N kg−1 DM) and high temperature (〉23°C) was also detected. Together, this multiplicative model accounted for 0·82 of the variation in Pmaxs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2494.2002.00302.x
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  • 4
    Electronic Resource
    Electronic Resource
    Flash vacuum pyrolysis. I. Allylcyclopentadiene from allyl phenyl ether (1967)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 89 (1967), S. 4213-4214 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00992a041
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    Flash vacuum pyrolysis. IV. The isolation and rearrangement of 9,10-dihydrofulvalene (1968)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 90 (1968), S. 5284-5286 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja01021a049
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    Paper (German National Licenses)
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  • 6
    Electronic Resource
    Electronic Resource
    Flash vacuum pyrolysis. X. Azocine. Flash vacuum pyrolysis of 7,8-diazapentacyclo[4.2.2.02,5.03,9.04,10]dec-7-ene (diazabasketene) (1971)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 93 (1971), S. 3817-3818 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00744a071
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    Paper (German National Licenses)
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  • 7
    Electronic Resource
    Electronic Resource
    Breeding for resistance to lentil Ascochyta blight (2002)
    Oxford, UK : Blackwell Publishing Ltd
    Plant breeding 121 (2002), S. 0 
    Details
    ISSN: 1439-0523
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Ascochyta blight, caused by Ascochyta lentis, is one of the most globally important diseases of lentil. Breeding for host resistance has been suggested as an efficient means to control this disease. This paper summarizes existing studies of the characteristics and control of Ascochyta blight in lentil, genetics of resistance to Ascochyta blight and genetic variations among pathogen populations (isolates). Breeding methods for control of the disease are discussed. Six pathotypes of A. lentis have been reported. Many resistant cultivars/lines have been identified in both cultivated and wild lentil. Resistance to Ascochyta blight in lentil is mainly under the control of major genes, but minor genes also play a role. Current breeding programmes are based on crossing resistant and high-yielding cultivars and multilocation testing. Gene pyramiding, exploring slow blighting and partial resistance, and using genes present in wild relatives will be the methods used in the future. Identification of more sources of resistance genes, good characterization of the host-pathogen system, and identification of molecular markers tightly linked to resistance genes are suggested as the key areas for future study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1439-0523.2002.00705.x
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  • 8
    Electronic Resource
    Electronic Resource
    Multiple cycloaddition reaction of 9,10-dihydrofulvalene. New approach to 3,4,7-methenocyclopenta[a]pentalene derivatives (1974)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 96 (1974), S. 4673-4674 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00821a053
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    Paper (German National Licenses)
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  • 9
    Electronic Resource
    Electronic Resource
    Identification of ancient heat treatment in flint artefacts by ESR spectroscopy (1978)
    [s.l.] : Nature Publishing Group
    Nature 276 (1978), S. 703-704 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Worked flint is the most abundant source of evidence for human activity before the advent of pottery-making cultures, and any information which can be deduced from it regarding its technology and date of fabrication is of considerable archaeological interest. Excavations frequently produce flint ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/276703a0
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  • 10
    Electronic Resource
    Electronic Resource
    Trapped methyl radicals in chert (1982)
    [s.l.] : Nature Publishing Group
    Nature 300 (1982), S. 435-436 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The organic radical signals have been observed in Upper Cretaceous lepispheric cherts from Europe and the Middle East, and in Tertiary chalcedonic cherts from south-west France. The chalcedonic cherts comprise a coarse, fibrous a-quartz (chalcedony) and the lepispheric cherts predominantly comprise ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/300435a0
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