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  • chlorophyll fluorescence  (3)
  • global optimization  (3)
  • pheromone  (3)
  • Springer  (9)
  • Macmillian Magazines Ltd.
  • 2000-2004
  • 1990-1994  (9)
  • 1935-1939
  • 1930-1934
Collection
Publisher
  • Springer  (9)
  • Macmillian Magazines Ltd.
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of insect behavior 7 (1994), S. 605-632 
    ISSN: 1572-8889
    Keywords: Heliothis ; Lepidoptera ; Noctuidae ; pheromone ; visual feedback
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract MaleHeliothis virescens (F.) (Lepidoptera: Noctuidae) were made to fly into a uniformly white and translucent tube within a large wind tunnel while responding to sex pheromone. Different visual patterns placed within the tube greatly affected the ability of the male moths to maintain upwind progress or remain oriented to the wind while in contact with the plume. Over 89% of males attempting to fly through a blank tube, lacking visual patterns, became disoriented, the males gaining or losing altitude and repeatedly hitting the sides of the tube. Patterns of 20–40 dots placed on the sides of the tube at or slightly above plume level resulted in high levels of sustained upwind flight (47–74%) relative to patterns placed directly below (30–40%), directly above (35%), or slightly below the level of the flight path (26–44%). Optimal upwind progression in pheromone-responding males occurred when image motion could be resolved both transversely (T), orthogonally to the longitudinal axis of the body relative to the horizontal plane of the environment, and longitudinally (L), along the body axis. Even very sparse patterns (single rows of dots) could elicit high levels of sustained upwind flight (53–63%) when positioned within the tube such that the males' movements would create both L and T image motion. However, successful negotiation of the tube was also unexpectedly facilitated by patterns apparently providing no horizontal transverse component for flying males but providing longitudinal flow while centering the moth in the plume through a symmetrical left-right input (4–40%).
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Annals of operations research 25 (1990), S. 181-196 
    ISSN: 1572-9338
    Keywords: Nonlinear algebraic systems ; Newton's method ; interval arithmetic ; Gauss-Seidel method ; global optimization ; singularities
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Economics
    Notes: Abstract Interval Newton methods in conjunction with generalized bisection are important elemetns of algorithms which find theglobal optimum within a specified box X ⊂ ℝn of an objective function ϕ whose critical points are solutions to the system of nonlinear equationsF(X)=0with mathematical certainty, even in finite presision arithmetic. The overall efficiency of such a scheme depends on the power of the interval Newton method to reduce the widths of the coordinate intervals of the box. Thus, though the generalized bisection method will still converge in a box which contains a critical point at which the Jacobian matrix is singular, the process is much more costly in that case. Here, we propose modifications which make the generalized bisection method isolate singular solutions more efficiently. These modifications are based on an observation about the verification property of interval Newton methods and on techniques for detecting the singularity and removing the region containing it. The modifications assume no special structure forF. Additionally, one of the observations should also make the algorithm more efficient when finding nonsingular solutions. We present results of computational experiments.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Photosynthesis research 37 (1993), S. 89-102 
    ISSN: 1573-5079
    Keywords: C4 photosynthesis ; chlorophyll fluorescence ; CO2 assimilation ; maize ; Photosystem II ; quantum yield
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Analysis is made of the energetics of CO2 fixation, the photochemical quantum requirement per CO2 fixed, and sinks for utilising reductive power in the C4 plant maize. CO2 assimilation is the primary sink for energy derived from photochemistry, whereas photorespiration and nitrogen assimilation are relatively small sinks, particularly in developed leaves. Measurement of O2 exchange by mass spectrometry and CO2 exchange by infrared gas analysis under varying levels of CO2 indicate that there is a very close relationship between the true rate of O2 evolution from PS II and the net rate of CO2 fixation. Consideration is given to measurements of the quantum yields of PS II (φ PS II) from fluorescence analysis and of CO2 assimilation ( $$\phi _{CO_2 } $$ ) in maize over a wide range of conditions. The $${{\phi _{PSII} } \mathord{\left/ {\vphantom {{\phi _{PSII} } {\phi _{CO_2 } }}} \right. \kern-\nulldelimiterspace} {\phi _{CO_2 } }}$$ ratio was found to remain reasonably constant (ca. 12) over a range of physiological conditions in developed leaves, with varying temperature, CO2 concentrations, light intensities (from 5% to 100% of full sunlight), and following photoinhibition under high light and low temperature. A simple model for predicting CO2 assimilation from fluorescence parameters is presented and evaluated. It is concluded that under a wide range of conditions fluorescence parameters can be used to predict accurately and rapidly CO2 assimilation rates in maize.
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  • 4
    ISSN: 1573-5079
    Keywords: chlorophyll fluorescence ; non-photochemical quenching ; photosystem II ; quenching analyses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of light-induced non-photochemical quenching on the minimal Fo, and variable Fv, fluorescence emissions at 690 and 730 nm in leaves were determined. Non-photochemical quenching of Fo, but not Fv, was found to be dependent upon the wavelength of emission, and was greater at 690 nm than at 730 nm. For emission at 730, compared to at 690 nm, approx. 30% of Fo was not affected by non-photochemical quenching processes in leaves of C3 plants; in maize leaves this was found to be approx. 50%. The data indicate that a substantial proportion of the pigments contributing to Fo emission at 730 nm are not quenched by light-induced, non-photochemical quenching processes and that there are large differences in the pigment matrices contributing to Fo and Fv emissions at 730 nm, compared to those at 690 nm. These findings have important implications for the accurate estimation and interpretation of non-photochemical quenching of fluorescence parameters and their use in the calculation of photochemical efficiencies in leaves. Measurements of fluorescence emissions at wavelengths above 700 nm are likely to give rise to significant errors when used for determinations of photochemical and non-photochemical quenching parameters.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1573-5079
    Keywords: chlorophyll fluorescence ; cation depletion ; chloroplast development ; electron transport ; light-harvesting chlorophyll proteins ; photosystem I ; protein phosphorylation ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of protein phosphorylation and cation depletion on the electron transport rate and fluorescence emission characteristics of photosystem I at two stages of chloroplast development in light-grown wheat leaves are examined. The light-harvesting chlorophyll a/b protein complex associated with photosystem I (LHC I) was absent from the thylakoids at the early stage of development, but that associated with photosystem II (LHC II) was present. Protein phosphorylation produced an increase in the light-limited rate of photosystem I electron transport at the early stage of development when chlorophyll b was preferentially excited, indicating that LHC I is not required for transfer of excitation energy from phosphorylated LHC II to the core complex of photosystem I. However, no enhancement of photosystem I fluorescence at 77 K was observed at this stage of development, demonstrating that a strict relationship between excitation energy density in photosystem I pigment matrices and the long-wavelength fluorescence emission from photosystem I at 77 K does not exist. Depletion of Mg2+ from the thylakoids produced a stimulation of photosystem I electron transport at both stages of development, but a large enhancement of the photosystem I fluorescence emission was observed only in the thylakoids containing LHC I. It is suggested that the enhancement of PS I electron transport by Mg2+-depletion and phosphorylation of LHC II is associated with an enhancement of fluorescence at 77 K from LHC I and not from the core complex of PS I.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of global optimization 2 (1992), S. 259-280 
    ISSN: 1573-2916
    Keywords: Primary: 65K10 ; Secondary: 65G10 ; Nonlinear algebraic systems ; Newton's method ; interval arithmetic ; Gauss-Seidel method ; global optimization ; singularities
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract In this paper, we propose modifications to a prototypical branch and bound algorithm for nonlinear optimization so that the algorithm efficiently handles constrained problems with constant bound constraints. The modifications involve treating subregions of the boundary identically to interior regions during the branch and bound process, but using reduced gradients for the interval Newton method. The modifications also involve preconditioners for the interval Gauss-Seidel method which are optimal in the sense that their application selectively gives a coordinate bound of minimum width, a coordinate bound whose left endpoint is as large as possible, or a coordinate bound whose right endpoint is as small as possible. We give experimental results on a selection of problems with different properties.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of global optimization 5 (1994), S. 253-265 
    ISSN: 1573-2916
    Keywords: Branch and bound principle ; inclusion function ; interval extensions ; midpoint test ; global optimization ; order of an interval extension ; nonconvex optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract We consider branch and bound methods for enclosing all unconstrained global minimizers of a nonconvex nonlinear twice-continuously differentiable objective function. In particular, we consider bounds obtained with interval arithmetic, with the “midpoint test,” but no acceleration procedures. Unless the lower bound is exact, the algorithm without acceleration procedures in general gives an undesirable cluster of boxes around each minimizer. In a previous paper, we analyzed this problem for univariate objective functions. In this paper, we generalize that analysis to multi-dimensional objective functions. As in the univariate case, the results show that the problem is highly related to the behavior of the objective function near the global minimizers and to the order of the corresponding interval extension.
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  • 8
    ISSN: 1573-1561
    Keywords: Flight tunnel ; gas chromatography-electrophysiology ; mass ; spectrometry ; aldehydes ; (Z,E)-9,11,13-tetradecatrienal ; (Z,E)-9,11-tetra-decadienal ; (Z)-9-tetradecenal ; pheromone ; Lepidoptera ; Pyralidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Three sex pheromone components of the carob moth were isolated and identified from the extract of female pheromone glands, using a variety of techniques including coupled gas chromatographic-electroantennographic recordings, coupled gas chromatographic-mass spectrometric analysis, microozonolysis, electroantennographic assays of monounsaturated standards, wind-tunnel bioassays, and field trials. The major component was identified as (Z,E)-9,11,13-tetradecatrienal, a novel lepidopterous pheromone component structure. Two minor components, either one of which improves the upwind flight response of males when blended with the major component, were identified as (Z,E)-9,11-tetradecadienal, and (Z)-9-tetra-decenal.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 18 (1992), S. 1595-1602 
    ISSN: 1573-1561
    Keywords: 3,4-Dihydro-2H-pyrrole ; pheromone ; Δ1-pyrroline ; [1H]NMR spectroscopy ; [13C]NMR spectroscopy ; equilibrium ; Mediterranean fruit fly ; Ceratitis capitata ; Diptera ; Tephritidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Several properties of the compound 3,4-dihydro-2H-pyrrole(A1-pyrroline), which has been reported as a component of the male-produced Mediterranean fruit fly pheromone, have been determined by [1H]- and [13C]nuclear magnetic resonance spectroscopy. The stability of Δ1-pyrroline in several solvents and at moderately elevated temperatures has been investigated, and it has been established that it exists as both a monomer and trimer in solution. Although equilibrium studies indicate that the trimer is thermodynamically more stable than the monomer in solution, only the monomer was found in the vapor phase based on infrared analysis.
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