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  • Pollen tube  (5)
  • Statistical thermodynamics  (2)
  • cycle equation  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of statistical physics 42 (1986), S. 647-687 
    ISSN: 1572-9613
    Keywords: Statistical thermodynamics ; social systems ; single-lane traffic ; collective behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract An effort is made to introduce thermodynamic and statistical thermodynamic methods into the treatment of nonphysical (e.g., social, economic, etc.) systems. Emphasis is placed on the use of theentire thermodynamic framework, not merely entropy. Entropy arises naturally, related in a simple manner to other measurables, but does not occupy a primary position in the theory. However, the maximum entropy formalism is a convenient procedure for deriving the thermodynamic analog framework in which undetermined multipliers are thermodynamic-like variables which summarize the collective behavior of the system. We discuss the analysis of Levine and his coworkers showing that the maximum entropy formalism is the unique algorithm for achieving consistent inference of probabilities. The thermodynamic-like formalism for treating a single lane of vehicular traffic is developed and applied to traffic in which the interaction between cars is chosen to be a particular form of the “follow-the-leader” type. The equation of state of the traffic, the distributions of velocity and headway, and the various thermodynamic-like parameters, e.g., temperature (collective sensitivity), pressure, etc. are determined for an experimental example (Holland Tunnel). Nearest-neighbor and pair correlation functions for the vehicles are also determined. Many interesting and suggestive results are obtained,
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of statistical physics 8 (1973), S. 299-307 
    ISSN: 1572-9613
    Keywords: Statistical thermodynamics of curved boundary layers ; scaled particle theory ; equation of state ; cycle equation ; fluid-solid phase transition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The thermodynamics of curved boundary layers, with the assumption that the distance between the surface of a fluid cavity and its surface of tension is a quadratic function of the cavity radius, is applied to the exact thermo-dynamic expression forG, the central function of scaled particle theory. The coefficients in the quadratic representation are determined so as to satisfyall five of the known exact conditions onG valid for cavity radii between one-half and one molecular diameter. The results of the calculation are displayed as the hard-sphere equation of state, the boundary tension associated with the surface of tension, and the distance between the cavity surface and the surface of tension. Although the hard-sphere equation of state obtained by this method using all five conditions onG is more accurate than in the case where only two or three conditions are used, the original scaled particle theory, in whichG itself was represented simply by a quadratic function of inverse powers of cavity radius, still yields the more accurate equation of state. Nevertheless, the present approach limits approximations to the distance between the cavity surface and the surface of tension, a small quantity in itself. The path to a still more improved theory remains well defined, contingent upon the discovery of additional exact conditions, and does not depend, as in the original scaled particle theory, on a form forG arrived at in a somewhat ad hoc manner.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of statistical physics 1 (1969), S. 107-131 
    ISSN: 1572-9613
    Keywords: Information theory ; Thermodynamic transformations ; Partition function ; Statistical thermodynamics ; Channel capacity ; Matching ; Noiseless channel ; Compact code
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract This article explores the application of thermodynamic and statistical thermodynamic formalism to information theory problems. In particular, the applicability of the transformation theory of thermodynamics is investigated. After a brief tutorial discussion of thermodynamic and statistical thermodynamic methods and concepts, their information theory analogues are developed. Besides information theory entropy, the information theory counterparts of temperature, chemical potential, Helmholtz free energy, etc., are developed and related to conventional information theory concepts such as channel capacity, matching of source and channel, etc. Information theory theorems are proved via the statistical thermodynamic analogue method; and, finally, several problems are formulated and solved using thermodynamic-like transformations. This article is aimed chiefly at bridging the interface between the two disciplines, and is intended to be provocative. Therefore, no attempt has been made to have it be all inclusive.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 131 (1986), S. 244-246 
    ISSN: 1615-6102
    Keywords: Calcium ion distribution ; Polar growth ; Pollen tube ; Quin-2 fluorescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Using the fluorescent calcium probe Quin-2, we could demonstrate a tip-to-base gradient of free calcium within growing pollen tubes ofLilium longiflorum. This result shows that it is possible to visualize calcium ions using Quin-2 in plant cells which are surrounded by a cell wall and that the calcium gradients demonstrated by CTC fluorescence (indicating membrane-bound calcium) and PIXE (showing total calcium) is paralleled by a gradient of free calcium in pollen tubes.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1615-6102
    Keywords: Lilium ; Pollen tube ; Calcium gradient ; Polarity ; Protoninduced X-ray emission (PIXE) ; The Heidelberg proton microprobe
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The intracellular calcium distribution in pollen tubes ofLilium longiflorum was measured by proton-induced X-ray emission (PIXE) with the Heidelberg proton microprobe, which is a new method for biological application. Studies by electron-induced X-ray emission (EIXE) were done in comparison. Independent of the preparation technique, the pollen tubes show a tip-to-base calcium gradient. The shape of the calcium gradient and the total calcium content depend on the preparation technique. The calcium ionophore A-23187 destroys the calcium gradient and leads to a loss of most cell calcium. Chlorotetracycline (CTC) treatment increases the amount of membrane-bound calcium.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1615-6102
    Keywords: Lilium ; Pollen tube ; Proton-induced X-ray emission (PIXE) ; The Heidelberg proton microprobe ; Polar zinc distribution ; mRNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The zinc distribution in pollen tubes ofLilium longiflorum was analysed by proton-induced X-ray emission (PIXE) with the Heidelberg proton microprobe. A very high zinc concentration was measured in the pollen tube tip region.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 139 (1987), S. 20-24 
    ISSN: 1615-6102
    Keywords: Calcium activity ; Calcium gradient ; Lilium ; Polar growth ; Pollen tube ; Quin-2 ; Microfluorimeter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Pollen tubes ofLilium longiflorum were loaded with quin-2 to determine the cytoplasmic free calcium. Quin-2-fluorescence was detected at 500 nm with alternating excitation at 340 nm and 360 nm. The calcium2+-concentration was obtained using the intensity ratio R=I340/I360. The analysis exhibits a [Ca2+] of nearly 10−7mol·l−1 in the tip region and about 2·10−8 mol·l−1at the tube base, near the pollen grain. The data give evidence for the existence of a continuous gradient of free calcium within growing pollen tubes of various length.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 185 (1995), S. 113-122 
    ISSN: 1615-6102
    Keywords: Cell wall ; Heavy metals ; Lilium ; Pollen tube ; Tip growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The influence of different concentrations of the heavy metals cadmium (Cd2+), cobalt (Co2+), copper (Cu2+), iron (Fe2+ and Fe3+), mercury (Hg2+), manganese (Mn2+), and zinc (Zn2+), plus aluminium (Al3+) (a toxic metal in polluted areas), on pollen germination and tube growth ofLilium longiflorum was investigated using light microscopy. Effects could be observed with 3 μM and 100 μM of heavy metal, added as chloride salts to the medium. Cd2+, Cu2+, and Hg2+, showed the greatest toxicity, whereas germination and growth rate was less affected by Mn2+. Affected tubes showed swelling of the tip region. Tubes treated with Cd2+, Co2+, Fe2+, Fe3+, Hg2+, and Mn2+ were also prepared for ultrastructural studies. In all cases, the main effect was abnormal cell wall organization, mostly at the tip, where round, fibrillar aggregates, the shape and size of secretory Golgi vesicles were formed. They built up a loose network which could be up to 10 μm thick compared to untreated tubes where the cell wall was composed of thin layers of long fibrils and about 100 nm thick. Cd2+ was the only metal which produced effects at the intracellular level: organelle distribution within the tip region appeared disorganized. A general mechanism of heavy metal action on pollen tube growth is discussed.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of statistical physics 7 (1973), S. 143-159 
    ISSN: 1572-9613
    Keywords: Statistical thermodynamics of curved boundary layers ; scaledparticle theory ; equation of state ; cycle equation ; fluid-solid phase transition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The thermodynamics of curved boundary layers is combined with scaled particle theory to determine the rigid-sphere equation of state. In particular, the boundary analog of the Gibbs-Tolman-Koenig-Buff equation is solved for a rigid-sphere fluid, using the approximation that the distance between the surface of a cavity and its surface of tension is a function of the density only (the first-order approximation). This, in conjunction with several exact conditions onG, the central function of scaled particle theory, leads to an approximate rigid-sphere fluid equation of state and a qualitatively correct rigid-sphere solid equation of state. The fluid isotherm compares favorably with previous results (2.9 % error in the fourth virial coefficient), but due to the inaccuracy of the solid isotherm, no phase transition is obtained. The theory described here is to be contrasted with previous approaches in that a less arbitrary functional form forG is assumed, and the surface of tension and cavity surface are not assumed to be coincident. The “cycle equation” of Reiss and Tully-Smith is rederived by a simpler route and shown to be correct to all orders of cavity curvature, rather than only first order as was originally thought. A new exact condition, obtained from the compressibility equation of state, is used as a boundary condition for the “cycle equation” to determine the location of the equimolecular surface. This molecular calculation compares favorably (discrepancy of 〈2 %) with a thermodynamic calculation based on the boundary analog of the Gibbs adsorption equation and indicates the accuracy and consistency of the first-order approximation.
    Type of Medium: Electronic Resource
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