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  • 1
    Digitale Medien
    Digitale Medien
    Group theory of the Smorodinsky–Winternitz system (1991)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 32 (1991), S. 3369-3375 
    Details
    ISSN: 1089-7658
    Quelle: AIP Digital Archive
    Thema: Mathematik , Physik
    Notizen: The three degrees of freedom Smorodinsky–Winternitz system is a degenerate or super-integrable Hamiltonian that possesses five functionally independent globally defined and single-valued integrals of the motion in both classical and quantum mechanics. This is explained in terms of a forced degeneracy imposed as a consequence of the invariance of the Hamiltonian under a group of symmetry transformations isomorphic to the three-dimensional unitary unimodular group, SU(3). In turn, this degeneracy group is embedded in a larger group of transformations that maps all the bound energy levels among each other, the so-called dynamical group. All the bound state eigenfunctions act as basis functions for a single irreducible representation of the dynamical group. So, in common with the hydrogen atom and the harmonic oscillator, the quantum mechanics of the Smorodinsky–Winternitz system may be completely solved within the framework of group theory alone.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.529449
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  • 2
    Digitale Medien
    Digitale Medien
    On Hamiltonian systems in two degrees of freedom with invariants quartic in the momenta of form p21p22⋅⋅⋅ (1990)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 31 (1990), S. 600-604 
    Details
    ISSN: 1089-7658
    Quelle: AIP Digital Archive
    Thema: Mathematik , Physik
    Notizen: A search is made for autonomous Hamiltonian systems in two degrees of freedom which admit a second invariant quartic in the momenta with leading term p21p22/ 2. A sufficient condition for the resulting functional equation to possess solutions is deduced and a family of integrable systems is identified, which under the equivalence class of linear transformations reduce to a simpler integrable system found originally by Bozis. The method of Lax pairs is used to find further solutions to the functional equation and give new classes of integrable but nonseparable Hamiltonians.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.528895
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  • 3
    Digitale Medien
    Digitale Medien
    Photophysics of the aniline blue fluorophore: a fluorescent probe showing specificity toward (1 .fwdarw. 3)-.beta.-D-glucans (1986)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 90 (1986), S. 5058-5063 
    Details
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/j100412a036
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  • 4
    Digitale Medien
    Digitale Medien
    Predicting light leaf spot (Pyrenopeziza brassicae) risk on winter oilseed rape (Brassica napus) in England and Wales, using survey, weather and crop information (2004)
    Oxford, UK : Blackwell Science Ltd
    Plant pathology 53 (2004), S. 0 
    Details
    ISSN: 1365-3059
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Data from surveys of winter oilseed rape crops in England and Wales in growing seasons with harvests in 1987–99 were used to construct statistical models to predict, in autumn (October), the incidence of light leaf spot caused by Pyrenopeziza brassicae on winter oilseed rape crops the following spring (March/April), at both regional and individual crop scales. Regions (groups of counties) with similar seasonal patterns of incidence (percentage of plants affected) of light leaf spot were defined by using principal coordinates analysis on the survey data. At the regional scale, explanatory variables for the statistical models were regional weather (mean summer temperature and mean monthly winter rainfall) and survey data for regional light leaf spot incidence (percentage of plants with affected pods) in July of the previous season. At the crop scale, further explanatory variables were crop cultivar (light leaf spot resistance rating), sowing date (number of weeks before/after 1 September), autumn fungicide use and light leaf spot incidence in autumn. Risk of severe light leaf spot (〉 25% plants affected) in a crop in spring was also predicted, and uncertainty in predictions was assessed. The models were validated using data from spring surveys of winter oilseed rape crops in England and Wales from 2000 to 2003, and reasons for uncertainty in predictions for individual crops are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-3059.2004.01105.x
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  • 5
    Digitale Medien
    Digitale Medien
    Sporulation of Pyrenopeziza brassicae (light leaf spot) on oilseed rape (Brassica napus) leaves inoculated with ascospores or conidia at different temperatures and wetness durations (2002)
    Oxford, UK : Blackwell Science Ltd
    Plant pathology 51 (2002), S. 0 
    Details
    ISSN: 1365-3059
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: In controlled environment experiments, sporulation of Pyrenopeziza brassicae was observed on leaves of oilseed rape inoculated with ascospores or conidia at temperatures from 8 to 20°C at all leaf wetness durations from 6 to 72 h, except after 6 h leaf wetness duration at 8°C. The shortest times from inoculation to first observed sporulation (l0), for both ascospore and conidial inoculum, were 11–12 days at 16°C after 48 h wetness duration. For both ascospore and conidial inoculum (48 h wetness duration), the number of conidia produced per cm2 leaf area with sporulation was seven to eight times less at 20°C than at 8, 12 or 16°C. Values of Gompertz parameters c (maximum percentage leaf area with sporulation), r (maximum rate of increase in percentage leaf area with sporulation) and l37 (days from inoculation to 37% of maximum sporulation), estimated by fitting the equation to the observed data, were linearly related to values predicted by inserting temperature and wetness duration treatment values into existing equations. The observed data were fitted better by logistic equations than by Gompertz equations (which overestimated at low temperatures). For both ascospore and conidial inoculum, the latent period derived from the logistic equation (days from inoculation to 50% of maximum sporulation, l50) of P. brassicae was generally shortest at 16°C, and increased as temperature increased to 20°C or decreased to 8°C. Minimum numbers of spores needed to produce sporulation on leaves were ≈25 ascospores per leaf and ≈700 conidia per leaf, at 16°C after 48 h leaf wetness duration.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-3059.2002.00746.x
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  • 6
    Digitale Medien
    Digitale Medien
    Comparative epidemiology of Pyrenopeziza brassicae (light leaf spot) ascospores and conidia from Polish and UK populations (2004)
    Oxford, UK : Blackwell Science Ltd
    Plant pathology 53 (2004), S. 0 
    Details
    ISSN: 1365-3059
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Despite differences in climate and in timing of light leaf spot epidemics between Poland and the UK, experiments provided no evidence that there are epidemiological differences between populations of Pyrenopeziza brassicae in the two countries. Ascospores of Polish or UK P. brassicae isolates germinated on water agar at temperatures from 8 to 24°C. After 12 h of incubation, percentages of ascospores that germinated were greatest at 16°C: 85% (Polish isolates) and 86% (UK isolates). The percentage germination reached 100% after 80 h of incubation at all temperatures tested. The rate of increase in germ tube length increased with increasing temperature from 8 to 20°C but decreased from 20 to 24°C, for both Polish and UK isolates. Percentage germination and germ tube lengths of UK P. brassicae ascospores were less affected by temperature than those of conidia. P. brassicae produced conidia on oilseed rape leaves inoculated with ascospores or conidia of Polish or UK isolates at 16°C with leaf wetness durations from 6 to 72 h, with most sporulation after 48 or 72 h wetness. Detection of both mating types of P. brassicae and production of mature apothecia on leaves inoculated with mixed Polish populations suggest that sexual reproduction does occur in Poland, as in the UK.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-3059.2004.00952.x
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  • 7
    Digitale Medien
    Digitale Medien
    Modelling the effects of temperature and wetness duration on development of light leaf spot on oilseed rape leaves inoculated with Pyrenopeziza brassicae conidia (2001)
    Oxford, UK : Blackwell Science Ltd
    Plant pathology 50 (2001), S. 0 
    Details
    ISSN: 1365-3059
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: A model was developed to describe the effects of temperature and leaf wetness duration in controlled-environment experiments on the development of light leaf spot on oilseed rape (cv. Bristol) leaves inoculated with Pyrenopeziza brassicae conidial suspensions. A Gompertz function was used to describe the progress with time in percentage leaf area with sporulation, and included the parameters maximum percentage leaf area with sporulation (c); maximum rate of increase in percentage leaf area with sporulation (r); and latent period (l, the time from inoculation until the leaf area with sporulation reached 37% of c). The effects of leaf wetness duration on c and r were also described with Gompertz functions, which included the parameters minimum leaf wetness duration (vc or vr); and maximum of c (mc) or maximum of r (mr). The effects of temperature on mc, vc and vr were described by quadratic functions, and the effect of temperature on mr was described by a linear function. The combined model described the progress with time in percentage leaf area with sporulation, including the effects of temperature and leaf wetness duration on the parameters c, r and l. It generally fitted well to the observed data. Latent periods in previously published experiments were predicted accurately by the model, but percentage leaf area with sporulation was not. Assuming a great number of conidia were dispersed and infection occurred when there was 2 mm h−1 rain for 0·5 h, the model estimates for latent period were used to predict the dates when large increases in light leaf spot severity occurred in experiments at Rothamsted on winter oilseed rape (cv. Bristol) under natural conditions in 1998/99 and 1999/2000. The predictions agreed with the observations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-3059.2001.00542.x
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  • 8
    Digitale Medien
    Digitale Medien
    Leptosphaeria maculans causing stem canker of oilseed rape in China (2000)
    Oxford, UK : Blackwell Science Ltd
    Plant pathology 49 (2000), S. 0 
    Details
    ISSN: 1365-3059
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-3059.2000.00503.x
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  • 9
    Digitale Medien
    Digitale Medien
    Effects of stem canker (Leptosphaeria maculans) and light leaf spot (Pyrenopeziza brassicae) on yield of winter oilseed rape (Brassica napus) in southern England (2000)
    Oxford, UK : Blackwell Science Ltd
    Plant pathology 49 (2000), S. 0 
    Details
    ISSN: 1365-3059
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: The relationships between yield loss and incidence or severity of stem canker and light leaf spot in winter oilseed rape were analysed by correlation and regression analyses, using data from experiments at Rothamsted, England in 1992/93, 1994/95 and 1995/96. Growth stages (GS) 6,3/6,4 and 4,0/4,5 were identified as the critical points for relating percentage yield loss to stem canker and light leaf spot (on stems), respectively. Critical point (CP) and area under disease progress curve (AUDPC) models relating percentage yield loss to combined incidence or severity of stem canker and light leaf spot (stems) in each experiment were constructed by linear regression. There were no differences in the CP models for incidence between 1992/93, 1994/95 and 1995/96 experiments, or in the AUDPC models for incidence between 1992/93 and 1994/95 experiments. Therefore, a general CP model relating percentage yield loss (ΔY) to combined incidence of stem canker (Si) at GS 6,3/6,4 and light leaf spot (stems) (Li) at GS 4,0/4,5 was constructed using data from the three experiments: ΔY = 0·85 + 0·079Si + 0·065Li (R2 = 43·7%, P 〈 0·001, 92 df). A general AUDPC model relating ΔY to the AUDPC of combined incidence of stem canker (Sia) from GS 5·7 to GS 6·5 and light leaf spot (stems) (Lia) from GS 4·0 to GS 6·3 was constructed using data from the 1992/93 and 1994/95 experiments: ΔY = 0·07 + 0·00096Sia + 0·0026Lia (R2 = 43·6%, P 〈 0·001, 68 df). These two general yield-loss models were tested with data from Rothamsted in 1993/94 and Boxworth in 1992/93. The predictive accuracy of the CP model based on combined incidence of stem canker and light leaf spot (stems) was better than that of the AUDPC model. Yield losses predicted by summing the estimates from individual models for incidence of stem canker alone (GS 6,3/6,4) and light leaf spot alone (on leaves at GS 3,3) were greater than observed yield losses in experiments at Rothamsted in 1992/93, 1993/94, 1994/95 and 1995/96 and at Boxworth in 1992/93.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-3059.2000.00475.x
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  • 10
    Digitale Medien
    Digitale Medien
    THE EFFECT OF RESPIRATORY MANOEUVRES UPON SKIN OXYGEN TENSION AND BLOOD FLOW (1968)
    Oxford, UK : Blackwell Publishing Ltd
    British journal of dermatology 80 (1968), S. 0 
    Details
    ISSN: 1365-2133
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: SUMMARY.— Oxygen tension at the surface of inflamed skin and alveolar oxygen tension were measured polarographically. Changes in blood flow were indicated by a water perfused thermocouple disc resting on the skin. Breath holding, voluntary hyperventilation, Valsalva's manoeuvre, coughing, Muller's manoeuvre and arterial occlusion all produced transient changes in skin oxygen tension. These could largely be explained in terms of the observed changes in alveolar oxygen tension and skin blood flow.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2133.1968.tb11914.x
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