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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Oecologia 81 (1989), S. 249-257 
    ISSN: 1432-1939
    Keywords: Adult diet ; Jalmenus evagoras ; Butterfly biology ; Longevity ; Fecundity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This study examines the effect that sugars and amino acids in the adult diet of Jalmenus evagoras can have on female feeding behaviour, somatic maintenance, longevity, fecundity and egg weight. The presence of sugars in their adult food stimulated butterflies of this species to feed, and they appeared to compensate for low (1% wt/wt) sugar diets by feeding for longer periods. Butterflies were also more likely to feed on diets containing amino acids than on water controls. The availability of sugar allowed females to maintain or even increase their body weight and fat body size, but amino acids had no effect on these variables. Individuals on the medium (25% wt/wt) sugar diet attained the greatest longevity. Female fecundity was increased as much as threefold by the availability of sugar. However, amino acids in the diet had no effect on either longevity or fecundity. Egg weight was not affected by the concentration of sugars or amino acids in the adult diet, but was correlated with the weight of the female butterfly. These results demonstrate that the availability of carbohydrates in the adult diet could play an important role in the population dynamics of this species. However, the presence of amino acids had little effect on most of the variables measured, nor was there any interaction effect between sugars and amino acids.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1434-601X
    Keywords: 29.20 ; 41.80.D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The first results are presented of electron cooling experiments in the Low-Energy Antiproton Ring (LEAR) at CERN, performed with a proton beam of about 50 and 21 MeV. The number of stored protons ranged from 107 to 3 × 109. Cooling times of the order 1 s and proton drag rates of up to 0.7 MeV/s were obtained. The capture of cooling electrons by protons producing hydrogen atoms was used to derive an effective electron temperature (0.25 eV). From the angular profile of the neutral hydrogen beam an upper limit of 3π mm.mrad could be deduced for the horizontal equilibrium proton-beam emittance. The lowest equilibrium momentum spread was 2 × 105 (FWHM), as derived from the analysis of the longitudinal Schottky signal. This Schottky signal exhibited an unusual behaviour with beam intensity and under certain conditions showed a doublepeak structure which was associated with collective beam noise. For very cold beams transverse instabilities were observed, which resulted in a rapid spill-off of protons and a stabilization at lower intensities. The threshold of these instabilities was raised by heating the proton or the electron beam. The cooling of a bunched proton beam was investigated. The reduction of the proton momentum spread led to bunch lengths of about 2 m, containing 3 × 108 protons.
    Type of Medium: Electronic Resource
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