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  • growth  (111)
  • Adaptation
  • Sound production
  • Springer  (141)
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  • American Geophysical Union (AGU)
  • 2005-2009  (1)
  • 2000-2004  (68)
  • 1980-1984  (73)
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  • 1
    Electronic Resource
    Electronic Resource
    Do Maculinea rebeli caterpillars provide vestigial mutualistic benefits to ants when living as social parasites inside Myrmica ant nests? (2000)
    Springer
    Entomologia experimentalis et applicata 95 (2000), S. 97-103 
    Details
    ISSN: 1570-7458
    Keywords: butterfly ; Formicidae ; food ; growth ; mutualism ; myrmecophily ; parasitism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Caterpillars of the lycaenid butterfly Maculinea rebeli Hirschke (Lepidoptera: Lycaenidae) live for 11–23 months as social parasites in Myrmica (Hymenoptera: Formicidae) red ant nests, a trait that is believed to have evolved from mutualistic myrmecophilous ancestry. Although Maculinea rebeli caterpillars harm Myrmica larvae, they simultaneously produce copious secretions which the adult worker ants imbibe, perhaps representing a vestige of the ancestral mutualism. We report the results of laboratory experiments designed to test alternative hypotheses: (i) Maculinea rebeli caterpillars provide a beneficial source of sugar in return for being tended by Myrmicaworkers; (ii) Maculinea rebeli harms its host by stressing the workers by competing for available sugar. Comparisons were made of Myrmica worker fitness after 90–450 days under all possible combinations of three experimental treatments: ± M. rebeli caterpillars, ± sucrose and ± ant brood. Caterpillars always reduced the survival of both ant workers and their larvae, even when sugar was not provided, suggesting that M. rebeli is wholly parasitic on all stages in its host colony. The results also confirmed the importance of sucrose in the diet of Myrmica, and showed that M. rebeli caterpillars which eat ant brood to supplement their normal trophallactic feeding by workers develop more quickly - but have the same survival and pupal weights – as caterpillars that are fed solely by worker ants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003950318095
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  • 2
    Electronic Resource
    Electronic Resource
    The influence of OH groups on the growth of rhodium on alumina: a model study (2000)
    Springer
    Catalysis letters 68 (2000), S. 19-24 
    Details
    ISSN: 1572-879X
    Keywords: aluminum oxide ; hydroxyl groups ; rhodium ; growth ; scanning tunneling microscopy ; infrared spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract In order to investigate how the presence of surface hydroxyl groups on oxide surfaces affects the interaction with the supported metal, we have modified a well-ordered alumina film on NiAl(110) by Al deposition and subsequent exposure to water. This procedure yields a hydroxylated alumina surface as revealed by infrared and high-resolution electron energy loss spectroscopy. By means of scanning tunneling microscopy, we have studied the growth of rhodium on the modified film at 300 K. Clear differences in the particle distribution and density are observed in comparison to the clean substrate. While, in the latter case, decoration of domain boundaries as typical defects of the oxide film governs the growth mode, a more isotropic island distribution and a drastically increased particle density is found on the hydroxylated surface. From infrared data, it can be deduced that the growth is connected with the consumption of the hydroxyl groups due to the interaction between the metal deposit and the hydroxylated areas. This finding is in line with photoemission results published earlier.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019058714724
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  • 3
    Electronic Resource
    Electronic Resource
    Bacillus sp. WW3-SN6, a novel facultatively alkaliphilic bacterium isolated from the washwaters of edible olives (2000)
    Springer
    Extremophiles 4 (2000), S. 201-208 
    Details
    ISSN: 1433-4909
    Keywords: Key words Olive wastes ; Bacillus ; Alkaliphile ; Growth characteristics ; Lipid composition ; Phylogeny ; Adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A novel Gram-positive facultatively alkaliphilic, sporulating, rod-shaped bacterium, designated as WW3-SN6, has been isolated from the alkaline washwaters derived from the preparation of edible olives. The bacterium is nonmotile, and flagella are not observed. It is oxidase positive and catalase negative. The facultative alkaliphile grows from pH 7.0 to 10.5, with a broad optimum from pH 8.0 to 9.0. It could grow in up to 15% (w/v) NaCl, and over the temperature range from 4° to 37°C, with an optimum between 27° and 32°C: therefore, it is both halotolerant and psychrotolerant. The bacterium is sensitive to a range of β-lactam, sulfonamide, and aminoglycoside antibiotics, but resistant to trimethoprim. The range of amino acids, sugars, and polyols utilized as growth substrates indicates that this alkaliphile is a heterotrophic bacterium. d(+)-glucose, d(+)-glucose-6-phosphate, d(+)-cellobiose, starch, or sucrose are the substrates best utilized. The major membrane lipids are phosphatidylglycerol and diphosphatidylglycerol, with smaller amounts of phosphatidylethanolamine and an unknown phospholipid. During growth at high pH, the proportion of phosphatidylglycerol is increased relative to phosphatidylethanolamine. The fatty acyl components in the membrane phospholipids are mainly branched chain, with 13-methyl tetradecanoic and 12-methyl tetradecanoic acids as the predominant components. The G + C content of the genomic DNA is 41.1 ± 1.0 mol%. The results of 16S ribosomal RNA sequence analysis place this alkaliphilic bacterium in a cluster, together with an unnamed alkaliphilic Bacillus species (98.2% similarity).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00010712
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  • 4
    Electronic Resource
    Electronic Resource
    The nutritional ecology of larvae of Alsophila pometaria and Anisota senatoria feeding on early- and late-season oak foliage (1984)
    Springer
    Entomologia experimentalis et applicata 35 (1984), S. 105-114 
    Details
    ISSN: 1570-7458
    Keywords: Alsophila pometaria ; Geometridae ; Anisota senatoria ; Citheroniidae ; Quercus ; nutritional ecology ; herbivory ; nutritional indices ; consumption ; growth ; utilization efficiency ; nitrogen ; water ; tannins ; phenols ; gut pH ; digestive enzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Alimentées sur feuillage jeune de chêne, les chenilles d'Alsophila pometaria avaient un taux relatif de croissance (RGR) et un taux relatif d'accumulation d'azote (RNAR) plus élevés que les chenilles d'Anisota senatoria alimentées sur feuillage mûr de chêne. Bien que le jeune feuillage soit plus efficacement digéré par A. pometaria (AD plus élevé), il n'est pas assimilé et utilisé pour la croissance avec de meilleurs rendements (les ECI ne sont pas différents). Ainsi le taux de croissance plus élevé d'A. pometaria est dû entièrement à un taux de consommation plus important (RCR et RNCR). Le feuillage jeune est significativement plus riche en azote et en eau que le feuillage mûr, mais les niveaux de phénol et de tanins sont les mêmes. A pometaria consomme les feuilles de différentes espèces de chênes au même taux, indépendamment de la teneur en azote, tandis que A. senatoria accroît sa consommation en réponse à une diminution de la teneur en azote. Il en résulte que le taux de croissance d'A. pometaria dépend directement de la teneur en azote des feuilles, tandis que celui d'A. senatoria en est indépendant. Les systèmes digestifs des deux insectes sont biochimiquement semblables et sont efficaces pour la digestion des protéines. Les tanins et les phénols n'influent pas sur les indices nutritionnels de ces deux espèces. Nous estimons que le principal intérêt de l'alimentation printanière est la disponibilité en feuillage succulent, riche en azote, et non l'absence de feuilles à haute teneur en tanin. L'alimentation printanière semble correspondre à une strategie alimentaire qui favorise la croissance aux dépens de l'efficacité tandis que l'alimentation en fin d'été est une stratégie qui favorise l'efficacité sur la rapidité.
    Notes: Abstract The larvae of Alsophila pometaria (Harr.), feeding on the young foliage of oak, has a higher relative growth rate (RGR) and relative nitrogen accumulation rate (RNAR) than the larvae of Anisota senatoria (J. E. Smith), feeding on the mature foliage of oak. Although the young oak foliage is more efficiently digested by A. pometaria (higher AD's), it is not more efficiently assimilated and used for growth (no difference in ECI's). Thus, the higher growth rate of A. pometaria is due entirely to a higher consumption rate (RCR and RNCR). Young foliage is significantly higher in nitrogen and water than mature foliage, but phenol and tannin levels are comparable in young and old foliage. A. pometaria consumes the foliage of different oak species at the same rate, independent of nitrogen content, while A. senatoria increases its consumption rate in response to decreased nitrogen levels. As a result, the growth rate of A. pometaria is directly related to leaf nitrogen content, while the growth rate of A. senatoria is independent of leaf nitrogen. The two species of insects have digestive systems that are very similar biochemically, and that are well-designed for effective protein digestion. Tannins and phenols do not influence the nutrional indices of either species. We suggest that the major benefit of spring feeding is the availability of succulent, high-nitrogen foliage, and not the avoidance of high-tannin foliage. The spring feeder appears to have a feeding strategy that favors rapid growth at the expense of efficiency, while the late summer feeder has a strategy that favors efficiency over rate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217527
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  • 5
    Electronic Resource
    Electronic Resource
    Sound production associated with feeding behaviour of the tsetse, Glossina M. morsitans (1983)
    Springer
    Entomologia experimentalis et applicata 34 (1983), S. 1-8 
    Details
    ISSN: 1570-7458
    Keywords: Glossina ; Tsetse ; Feeding ; behaviour ; Sound production ; Sound frequency ; Sound intensity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'étude a porté sur les sons produits pendant les comportements préalimentaire, alimentaire et postalimentaire de la mouche Tsétsé, Glossina morsitans morsitans. Les mâles et les femelles vierges chantent très rarement avant l'alimentation, mais les femelles fécondées chantent dans plus de 20% des cas avant de prendre un repas. La production de sons pendant la prise de nourriture était négligeable pour les trois catégories. Les sons postalimentaires étaient plus fréquents, les femelles fécondées chantant plus que les femelles vierges et l'ensemble des femelles plus que les mâles. La durée des sons postalimentaires ne différait pas suivant les sexes. Dans chaque catégorie, les sons postalimentaires ne changaient pas significativement avec l'âge. Il y a eu, cependant, des différences significatives dans les caractéristiques de la production de son postalimentaire lorsque les mâles étaient comparés aux femelles pendant une période de 8 semaines. Les oscillogrammes de ces sons différaient suivant le sexe et variaient de temps en temps. Les sons comportaient des fréquences jusqu' à 50 kHz, à l'exception des sons préalimentaires des mâles qui ne contenaient pas d'ultrasons. Les fréquences les plus dominantes étaient concentrées entre 1,5–2,5 kHz. Des pics étaient observés entre 0,5–0,8 kHz et autour de 5 kHz et 9 kHz. Les sons préalimentaires étaient plus faibles que les sons postalimentaires. On en suggère que les sons associés au comportement alimentaire jouent un rôle en attirant les mouches affamées vers un hôte convenable et que la plus grande partie de l'information acoustique est portée par les composantes à basse fréquence qui ont une intensité plus élevée (30–40 dB) que les fréquences ultrasoniques (10 dB).
    Notes: Summary Sounds produced during prefeeding, feeding and postfeeding behaviour of the tsetse, Glossina m. morsitans Westw. were investigated. Males and virgin ♀ ♀ very seldom sang before feeding but mated ♀ ♀ sang in more than 20% of the cases before taking a meal. Sound production during engorgement was negligible among all 3 groups. Postfeeding sounds were the most commonly produced, mated ♀ ♀ singing significantly more than virgin ♀ ♀ and both these groups more than ♂ ♂. The mean duration of the postfeeding sounds did not differ between the sexes. Within each group, postfeeding sound production did not significantly change with age. There were, however, significant differences in the patterns of postfeeding sound production when ♂ ♂ were compared to ♀ ♀ over a period of 8 weeks. Oscillograms of these sounds indicated that the songs differed between the sexes and also varied from time to time. The sounds were composed of frequencies up to 50 kHz with the exception of the ♂ prefeeding sounds which did not contain any ultrasonic components. The most dominant frequency was centered between 1.5–2.5 kHz. Peaks were also observed between 0.5–0.8 kHz and around 5 kHz and 9 kHz. Prefeeding songs were of a weaker intensity than postfeeding songs. It is suggested that the sounds associated with feeding behaviour play a role in attracting hungry flies to suitable hosts and that, the low frequency components having higher intensities (30–40 dB) than the ultrasonic frequencies (10 dB) carry the most important part of the acoustic information.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00300892
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  • 6
    Electronic Resource
    Electronic Resource
    Effects of diet on growth, fecundity and duration of tethered flight of Nezara viridula (1984)
    Springer
    Entomologia experimentalis et applicata 35 (1984), S. 75-81 
    Details
    ISSN: 1570-7458
    Keywords: Nezara viridula ; insect dietetics ; growth ; fecundity ; flight capacity ; Heteroptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les effets du régime alimentaire pendant le 5ème stade sur les performances imaginales de N. viridula ont été déterminés en comparant la croissance, la fécondité, la durée du vol captif, et l'accumulation de corps gras chez des insectes élevés sur 4 régimes stérilisés. A partir de la formation des larves de 5ème stade, elles ont été alimentées sur haricots verts et arachides, ou transférées sur un régime formé exclusivement d'arachides, ou de haricots verts, ou de graines de soja ‘trempées’, cependant la durée du 5ème stade. Les insectes ont été transférés sur un régime de haricots verts et arachides à leur émergence. Les femelles élevées continuellement de haricots verts et arachides étaient plus lourdes (P〈0,01) à l'émergence (161,6 mg) que celles élevées sur haricots verts (146,3 mg) pendant le 5ème stade, et pondent plus d'oeufs (P〈0,08) pendant une durée de 34 jours (100,9 oeufs) que celles élevées sur arachides (54,7 oeufs). Plus de femelles élevées sur haricots verts et arachides (76,2%) pondent que celles élevées sur arachides (61,1%), soja ‘trempé’ (62,5%), ou haricots verts (60,9%). Les femelles élevées sur arachides volaient plus longtemps (P 〈 0,01) (42,9 mn) que celles élevées sur haricots verts (19,8 mn) pendant des vols captifs le 3ème jour après l'émergence. 78% de toutes les femelles élevées sur arachides volaient 〉-30 mn, contre 50% pour celles élevées sur haricots verts et arachides, ou soja ‘trempé’, et 35% pour celles élevées sur haricots verts. Seulement 7% des femelles élevées sur haricots verts volaient à la 60ème minute à la fin du test, contre 25% pour les femelles soja ‘trempé’, 33% pour les femelles haricots verts et arachides, et 47% pour celles élevées sur arachides. Les femelles ont été disséquées 34 jours après l'émergence pour déterminer l'importance du corps gras. Les indices de corps gras (Kiritani, 1963) montraient que les femelles élevées sur arachides (1,8) et graines de soja (1,7) ont apparemment un corps gras plus développé que celles élevées sur haricots verts et arachides (1,5), our haricots verts (1,2), pendant le 5ème stade. Ces résultats montrent que l'alimentation pendant le dernier stade larvaire de N. viridula affecte irréversiblement la croissance, la fécondité et l'aptitude au vol des femelles. En estimant que des résultats semblables auraient été obtenus avec des insectes élevés sur ces 4 aliments depuis l'éclosion, haricots verts et arachides constituent le meilleur aliment pour l'élevage de N. viridula. Ce régime fournit une graine mûre, vraisemblablement nécessaire pour l'accumulation d'un corps gras suffisant et une aptitude au vol migratoire, et une plante verte qui fournit les aliments apparement essentiels à l'ovogenèse.
    Notes: Abstract The effects of diet during the fifth stadium on performance of adult N. viridula were determined through comparing growth, fecundity, and duration of tethered flight of insects reared on four axenic diets: fresh green bean, raw-shelled peanut, a combination of the two and soaked soybean seed. Females reared on the combination diet were heavier than those reared on green beans and oviposited more than those reared on peanuts. Three-day-old adult females reared on peanuts flew longer than those reared on green beans. More females reared on diets containing mature seed showed a capacity for extended flight and had larger fat bodies at 34-days postemergence. Thus, inadequate diet during the fifth stadium irreversibly affected growth, development, reproduction and flight capacity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00343462
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  • 7
    Electronic Resource
    Electronic Resource
    Ecology of black beetle Heteronychus arator. Influence of plant species on larval consumption, utilization and growth (1981)
    Springer
    Entomologia experimentalis et applicata 29 (1981), S. 109-116 
    Details
    ISSN: 1570-7458
    Keywords: Heteronychus arator ; Scarabaeidae ; larvae ; consumption ; utilization ; growth ; feeding ; roots ; Paspalum dilatatum ; Lolium perenne ; Trifolium repens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Futteraufnahme, die Futterverwertung und das Wachstum von Drittstadiumlarven von H. arator beim Fressen von Wurzeln von Paspalum dilatatum, Raygras (Lolium perenne) und Weissklee (Trifolium repens) wurden gravimetrisch gemessen. Der durchschnittliche Futterverzehrindex auf Gräsern war 0.65 mg/mg Larve/Woche verglichen mit 0.18 auf Weissklee. Die relative Wachstumsrate auf Paspalum und Raygras was 0.158 und 0.124 mg/mg Larve/Woche verglichen mit 0.043 auf Weissklee, was den geringen Verzehr an Weisskleewurzel widerspiegelt. Die Verwertung der gefressenen Wurzel war 22%, 18% und 24% für Paspalum, Ryagras und Weissklee. Das Fehlen gesicherter Unterschiede in der Futterverwertung der drei Pflanzenarten deutet darauf hin, dass die geringe Wachstumsrate auf Weissklee bloss durch geringe Futteraufnahme verursacht ist. Es wurde gezeigt, dass in Weisskleewurzel Frasinhibitoren für H. arator vorhanden sind. Die erhaltenen Schätzungen für Futteraufnahme durch Scarabaeiden sind die besten Daten für wurzelfressende Arten und liefern eine Basis, um den Einfluss der Weidepflanzen auf H. arator Populationen zu verstehen.
    Notes: Abstract The consumotion, utilization and growth of third-instar larvae of black beetle, Heteronychus arator (F.) feeding on roots of ryegrass (Lolium perenne), paspalum (Paspalum dilatatum) and white clover (Trifolium repens) were studied. Consumption was greater on the grasses than on white clover when assessed by gravimetric methods. Larvae had a higher growth rate on the grasses. Utilization of the roots of the three species was similar indicating that poor growth on white clover is the result of low consumption probably induced by the presence of feeding deterrents in the roots.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00300756
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  • 8
    Electronic Resource
    Electronic Resource
    Do Small Innovating Firms Outperform Non-Innovators? (2000)
    Springer
    Small business economics 14 (2000), S. 195-210 
    Details
    ISSN: 1573-0913
    Keywords: growth ; manufacturing ; performance ; product innovation ; small firms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract The paper considers the relative performance [along a number of parameters] of a sample of 228 small manufacturing firms categorised by level of innovation. Whilst innovators appear no more likely to have experienced some form of sales or employment growth, they are significantly more likely to have grown more. In other words, the innovators' growth rate distributions are highly negatively skewed. With regards to export intensities, profitability and productivity levels, the findings are less clear. On the whole, the results reported here are similar to those of other small firm studies, yet vary markedly from large firm equivalents; suggesting that the nature of the returns to innovation may be contingent, at least in part, upon firm size. Moreover, the high levels of variation in firm performance should caution us against proffering innovative imperatives. If we are to counsel firms to "innovate at all costs", we must be clear about, and clearly demonstrate, the nature of the returns they may reasonably expect and the processes through which these may be optimised.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008100206266
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  • 9
    Electronic Resource
    Electronic Resource
    Effects of rate and timing of nitrogen dressings on grain yield formation of winter wheat (T. aestivum L.) (1980)
    Springer
    Nutrient cycling in agroecosystems 1 (1980), S. 177-190 
    Details
    ISSN: 1573-0867
    Keywords: winter wheat ; nitrogen uptake ; autumn dressing ; split-dressing ; growth ; grain yield ; protein content ; harvest-index
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A field experiment with the winter wheat cultivar Donata was carried out on a fine-textured river clay soil in 1978. The rates of nitrogen dressing ranged from 0 to 160 kg N per ha and were split over from one up to three application times: autumn, early spring and late spring. Total above-ground dry matter and grain dry-weight yields ranged from 9.1 to 13.7 tons per ha and from 4.17 to 6.35 tons per ha, respectively. Late top-dressings increased the harvest-index, whereas an autumn dressing had the opposite effect. Number of culms per m2, grain weight (mg) and grain number per m2 increased from 350 to 430, from 35.5 to 36.8 and from 11 680 to 16 980, respectively, as the nitrogen dosage was raised from 0 to 160 kg N per ha. The linear rate of grain growth ranged from 111 to 172 kg dry matter per ha per day with nitrogen doses from 0 to 160 kg N per ha. Differences in rate of grain growth per unit area were mainly related to number of grains per m2. The association between grain number and grain yield was reflected by a correlation coefficient of 0.97 (n = 32). A higher level of nitrogen dressing enhanced the leaf area index and leaf area duration. However, we could not derive an effect of nitrogen on the duration of grain growth. Total nitrogen yield ranged from 71 to 166 kg N per ha and grain nitrogen yield from 54 to 122 kg N per ha with nitrogen dosages of 0 and 160 kg N per ha, respectively. The nitrogen concentration of the grains varied between 1.3 and 2.0 N. An autumn dressing of 40 kg N per ha generally showed only minor effects on yield and yield components. Top dressings during spring resulted in a higher recovery and efficiency of the applied nitrogen. Therefore, it may be concluded from this experiment and literature that on fertile soils an autumn dressing of nitrogen will not be economical, but split-dressings in spring are very beneficial. In particular, a late nitrogen application during the boot stage increased grain number, harvest-index and grain yield as well as protein concentration of the grain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01053130
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  • 10
    Electronic Resource
    Electronic Resource
    Effect of sodium iodide on growth and chemical composition of lucerne and ryegrass (1982)
    Springer
    Nutrient cycling in agroecosystems 3 (1982), S. 25-36 
    Details
    ISSN: 1573-0867
    Keywords: iodine ; lucerne ; ryegrass ; growth ; chemical composition ; nutrient-solutions ; ammoniacal and nitrate nitrogen ; acidity ; volatilization ; fertilizers ; grazing animals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Growth of lucerne was inhibited by sodium iodide even more than that of ryegrass above a concentration equivalent to 1µg cm−3 of iodine in an applied solution. In sand-culture the extent to which the iodide depressed yield of dry matter depended on the type of nutrient-solution used to stimulate and maintain vigorous growth. In contrast, where the plants were grown in soil the depression was independent of the nutrient-solution used. This difference between solutions is a reflection of the extent to which growing plants can modify pH in the root-zone of a sandy unbuffered substrate and leads to a conclusion that acidity greatly enhances the toxic effect of the iodine. There are reasons for believing that in sunlight iodine may be lost by volatilization even from living plant-tissue. The implication of these findings is discussed in relation to using either iodized fertilizers or iodized salt-blocks in order to maintain iodine in pastoral systems at levels satisfactory for animal-health.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01063407
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  • 11
    Electronic Resource
    Electronic Resource
    Method for culturing mammary epithelial cells in a rat tail collagen gel matrix (1983)
    Springer
    Methods in cell science 8 (1983), S. 31-36 
    Details
    ISSN: 1573-0603
    Keywords: growth ; differentiation ; mammary epithelium ; collagen gel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mammary glands are enzymatically dissociated and the resulting tissue digest enriched for epithelial cells by isopycnic banding on a density gradient of Percoll. The cells are embedded within a rat tail collagen gel matrix and fed with the appropriate medium. Growth and differentiation are superior in such a system when compared to culture on plastic, using identical media.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01834632
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  • 12
    Electronic Resource
    Electronic Resource
    Can strains give adequate information for adaptive bone remodeling? (1984)
    Springer
    Calcified tissue international 36 (1984), S. S118 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Strain ; Remodeling ; Adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary For bone to remodel adaptively, the cells responsible should follow some algorithm. Nine different loading situations and structures are discussed. It seems that either algorithm must be extremely complex, or cells in different structures must follow different algorithms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02406144
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  • 13
    Electronic Resource
    Electronic Resource
    The correlation of the receptor potential with the light induced transient increase in intracellular calcium-concentration measured by absorption change of arsenazo III injected into Limulus ventral nerve photoreceptor cell (1980)
    Springer
    European biophysics journal 6 (1980), S. 191-208 
    Details
    ISSN: 1432-1017
    Keywords: Receptor potential ; Intracellular and extracellular calcium concentration ; Intensity dependence ; Adaptation ; Sensitivity control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract The light-induced membrane voltage response (receptor potential, ReP) and the absorption change of the intracellularly injected calcium indicator arsenazo III (arsenazo response) were recorded simultaneously in Limulus ventral nerve photoreceptor cells. A double pulse technique was applied for stimulation. After pressure injection of the indicator into the cell absorption changes were measured at 646 nm to obtain a measure of the changes of the intracellular calcium ion concentration. 1. The size of the arsenazo response increases with increasing intensity of the light stimulus. The intensity dependence of the size of the arsenazo response δAmax shows almost no correlate with the peak amplitude of the ReP, but correlates rather well with the time integral of the ReP. 2. Decreasing light adaptation (caused by prolongation of the repetition time of the pulse pairs) leads to an increase in size of the arsenazo response. Also here δAmax correlates better with the time integral of the ReP than with its peak amplitude. 3. Lowering the calcium concentration in the superfusate (from 10 mmol/l to ca. 40 Μmol/l) causes after ca. 10 min a drastical diminution of the arsenazo response to values below the noise level, and a less marked reduction in size of the ReP. The falling phase of the ReP is slower. After return to normal calcium concentration the arsenazo response recovers partly in ca. 50 min, while the ReP recovers faster. The results show two opposite correlations between ReP and arsenazo response: Increase in size and duration of the ReP causes a greater transient increase of the intracellular calcium ion concentration. This in turn tends to reduce and shorten the ReP. Which effect dominates obviously depends on the conditions of the experiment: when the calcium concentration in the superfusate is reduced to ca. 40 Μmol/l a slow decrease of the ReP is accompanied by a small increase of the intracellular calcium ion concentration.
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    Adaptation properties of the ERG in the grasshopper, Romalea microptera (1981)
    Springer
    European biophysics journal 7 (1981), S. 205-208 
    Details
    ISSN: 1432-1017
    Keywords: Grasshopper ; Electroretinogram ; Adaptation ; Spectral sensitivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract The grasshopper ERG displays a rapid recovery of responsivity following the onset of a background light. Although observed earlier in skate and frog, this phenomenon has not previously been seen in an invertebrate. Furthermore, a period of hyperresponsivity exists in early dark adaptation and resembles that found in skate and frog. Thus, recovery in the light and hyperresponsivity in the dark seem to be corollaries of each other. Finally, spectral sensitivity of the ERG is determined and two peaks are found: one at 510 nm and the other at 360 nm. The former appears to be a rhodopsin-mediated sensitivity but the latter does not and they are not clearly separated by chromatic adaptation.
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    URL: http://dx.doi.org/10.1007/BF00539180
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    The contribution of pigment transitions to sensitivity changes in the barnacle photoreceptor and the correlation with the prolonged depolarizing afterpotential (1982)
    Springer
    European biophysics journal 8 (1982), S. 161-172 
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    ISSN: 1432-1017
    Keywords: Photoreceptor ; Visual pigment ; Adaptation ; Facilitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract A conditioning light can cause a decrease (adaptation) or an increase (facilitation) in the sensitivity of barnacle photoreceptors, as measured by the amplitude of the late receptor potential (LRP). We show that a net transfer of visual pigment from the rhodopsin (R) to the metarhodopsin (M) state induces a large facilitation whereas the reverse transfer results in a much smaller facilitation or even an adaptation. These effects were not due to the response to the conditioning light but to the pigment reactions. When the conditioning light did not alter the pigment population (i.e., M → M, R → R) it was followed by an intermediate degree of facilitation. These conclusions are correct for cells which have relatively low sensitivity. In sensitive cells, all pigment transitions produce adaptation. LRP facilitation and the prolonged depolarizing afterpotential (PDA) show several common characteristics with respect to pigment transitions: 1.Their magnitude increases with the amount of pigment transferred from R to M. 2. Both are depressed by the M → R transition. 3. Their production is impeded by the M → R transition. 4. The PDA itself is facilitated by the R → M transition and this facilitation decays with a time course comparable to that of LRP facilitation. These results suggest that there may be an underlying process common to LRP facilitation and PDA.
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    Sensitivity changes of photoreceptor cells of Hirudo medicinalis caused by changes in extracellular calcium concentration (1982)
    Springer
    European biophysics journal 8 (1982), S. 173-187 
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    ISSN: 1432-1017
    Keywords: Leech photoreceptors ; Extracellular calcium ; Excitation ; Adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract Extracellular recordings from the vacoule of photoreceptor cells of Hirudo medicinalis L. were performed using microelectrodes. The cells were adapted by white light flashes given at constant intervals (20 s). Response height versus relative intensity curves obtained from the same cell in physiological saline (PS) and in bathing solutions of either a) lowered calcium contents (2 ΜM/1 or less) or b) raised calcium contents (15 mM/1) were compared. The cells' adaptation state in PS was operationally defined by the ratio Q=h A /h S where h A is the response height evoked by the adapting flashes, and h S is the corresponding saturation response height. Sensitivity changes were measured by the half saturation intensity shift. Lowering extracellular calcium resulted in: 1. The response height increased and the shape of the response became more rounded and prolonged. 2. The total resistance between the vacuole and outside decreased from 8.2±1.4 MΩ (n=6) in PS to 4.6±0.4 MΩ (n=5). The resistance was independent of the cells' adaptation state. 3. A change of the cells' sensitivity occured either in direction to light adaptation or in direction to dark adaptation. It depended functionally on the ratio Q: a) if Q was less or equal to about 0.6 the cells' sensitivity increased. b) if Q was greater than 0.6 the cells' sensitivity diminished. Raising extracellular calcium decreased the sensitivity of all cells tested independent of their adaptation states in PS. The results can be interpreted under the assumptions that 1. the sensitivity of leech photoreceptor cells is inversely proportional to the intracellular free calcium concentration and Z. intracellular calcium can interact with extracellular calcium in relatively dark adapted cells whereas in relatively light adapted cells the raise of intracellular free calcium is mainly effected by a release from intracellular stores. It is assumed that a Q value of about 0.6 separates relatively light adapted cells from relatively dark adapted cells.
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    Education funding and regional convergence (2000)
    Springer
    Journal of population economics 13 (2000), S. 403-424 
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    ISSN: 1432-1475
    Keywords: JEL classification: O41 ; F22 ; Key words: Altruism ; education ; growth ; convergence ; capital mobility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Sociology , Economics
    Notes: Abstract. The aim of this paper is to discuss the process of regional convergence within the framework of an overlapping generations model in which the engine of growth is the accumulation of human capital. In particular, we consider different education funding systems and compare their performance in terms of growth rates and pace of convergence between two heterogeneous regions. The analysis suggests that the choice of a particular education system incorporates a possible trade-off between long run growth rate and short run convergence. In such choice, the initial capital stock and the extent of regional human capital discrepancy appear as central variables.
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    URL: http://dx.doi.org/10.1007/s001480050144
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    Growth of bacteria at 100°C and beyond (1981)
    Springer
    Archives of microbiology 129 (1981), S. 127-128 
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    ISSN: 1432-072X
    Keywords: Continuous culture ; Adaptation ; Simulation of hot springs ; Boiling point ; Caldoactive bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Bacillus caldolyticus, a caldoactive bacterium originating from a hot spring at Yellowstone Park, was grown in a defined medium, whose composition resembled that of the pool water. Using a chemostat culture, which simulated the natural conditions, the organism could be adapted to grow at 100°C at a reasonable rate. Under increased pressure growth occurred also at 105° C.
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    Properties of enzymes from bacteria grown in the 70–100°C range (1981)
    Springer
    Archives of microbiology 130 (1981), S. 159-164 
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    ISSN: 1432-072X
    Keywords: Adaptation ; Boiling point ; Caldoactive enzymes ; Stabilization ; Thermostability ; Thermal characteristics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In chemostat cultures of Bacillus caldolyticus, adaptation in a single step from 70–100°C was followed under aerobic and oxygen-limited conditions and was found to proceed more smoothly under the latter circumstances. Variations of the medium (e.g. yeast extract or silicate concentrations) showed that growth at 100°C is in all respects similar to that of cultures at moderate temperatures. Enzyme preparations derived from cultures at 5°C intervals between 70 and 100°C were used to determine the temperature range. For all nine enzymes tested, the optimum temperature was found to be 67°C; the latter was independent of the growth temperature. Differences were found, however, with respect to the maximum temperature of individual enzymes, and three groups, with maxima between 70 and 80°C, 80 and 90°C and 90 and 100°C can be distinguished. Again, there was no correlation with the growth temperature. Stability experiments also revealed that enzymes from the same organism can have different thermal properties: Some were found to be quite thermolabile (e.g. the pyruvate kinase), while others (e.g. hexokinase and glutamate-pyruvate transaminase) exhibited a high thermostability. These properties were not related to the growth temperature within the 70–100°C range, too. Six of the enzymes tested could be stabilized by their respective substrates, but the degree of protection varied for individual enzymes. Three enzymes (acetate kinase, glutamate dehydrogenase and myokinase) could not be stabilized by their substrates. Comparative experiments with the hexokinase suggested, that the thermal integrity of the enzymes is better protected within the cell as compared to the stability of the enzyme preparations.
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    Effects of sodium chloride on the plasma membrane of halotolerant Dunaliella primolecta: an electron spin resonance study (1982)
    Springer
    Archives of microbiology 131 (1982), S. 184-190 
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    ISSN: 1432-072X
    Keywords: Dunaliella primolecta ; Malotolerant ; Adaptation ; Plasma membrane ; ESR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Electron spin resonance spectroscopy was used to monitor the in vivo microviscosity of the plasma membrane and lipid extracts of the salt tolerant alga, Dunaliella primolecta. The fluidity of the plasma membrane decreased as the algae were adapted to and suspended in higher sodium chloride concentrations [2–24% (w/v)]. Both biochemical modification and a physical interaction between Na+ and lipids were implicated. When the microviscosity of the plasma membrane and that of lipid extracts were determined as a function of temperature, two or three lipid phase transformations were observed. There were always transformations at 9–14° C and 39–43° C. These were interpreted as the onset and completion of the lipid phase transition of at least a major lipid component of the membrane, possibly the entire membrane. These transformation temperatures were independent of the salt concentration to which the algae were adapted or suspended. This suggests that D. primolecta exists with some of its membrane in the solid-fluid mixed lipid state. With a NaCl concentration of 8% (w/v) or greater in the growth medium, a third transformation occurred around 20–22° C. It was the result of a lipid-lipid interaction and was not related to adaptation.
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    Photosensory transduction in the flagellated alga, Euglena gracilis (1983)
    Springer
    Archives of microbiology 134 (1983), S. 204-207 
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    ISSN: 1432-072X
    Keywords: Photosensory ; Cations ; pH ; Flagellated ; Algae ; Adaptation ; Euglena gracilis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Euglena were cultured under 3 W m-2 constant white light. In culture medium, cells show immediate and long lasting step-down photophobic responses and photoaccumulation behavior to blue light if dim red light-adapted for 30 min. However, if cells are suspended in buffered, saltcontaining solutions (adaptation buffers), strong step-down photobehavior and photoaccumulation responses are not observed for several hours. These behaviors gradually increase in strength to reach a maximum after 6–12 h; after which a stable response is maintained. The relative rates of appearance and the relative strengths of the responses are influenced by the concentrations of Ca2+ and K+, but not H+ or Na+ ions, in the adaptation buffers. Expression of the stepdown photobehavior thus requires that the cells adapt to the chemical environment in which they are suspended.
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    Ultra-violet mutagenesis of Synechocystis sp. 6701: mutations in chromatic adaptation and phycobilisome assembly (1984)
    Springer
    Archives of microbiology 138 (1984), S. 237-243 
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    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Synechocystis 6701 ; Phycobilisomes ; Ultra-violet ; Mutagenesis ; Assembly ; Chromatic ; Adaptation ; Rods ; Cores
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mutations affecting pigmentation of the cyanobacterium Synechocystis sp. 6701 were induced with ultraviolet light. Two mutants with phycobilisome structural changes were selected for structural studies. One mutant, UV08, was defective in chromatic adaptation and incorporated phycoerythrin into phycobilisomes in white or red light at a level typical of growth in green light. The other mutant, UV16, was defective in phycobilisome assembly: little phycocyanin was made and none was attached to the phycobilisome cores. The cores were completely free of any rod substructures and contained the major core peptides plus the 27,000 Mr linker peptide that attaches rods to the core. Micrographs of the core particles established their structural details. Phycoerythrin in UV 16 was assembled into rod structures that were not associated with core material or phycocyanin. The 30,500 Mr and 31,500 Mr linker peptides were present in the phycoerythrin rods with the 30,500 Mr protein as the major component. Phycobilisome assembly in vivo is discussed in light of this unusual mutant.
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    Theoretical considerations on growth kinetics and physiological adaptation of nutrient-limited phytoplankton (1984)
    Springer
    Archives of microbiology 140 (1984), S. 96-100 
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    ISSN: 1432-072X
    Keywords: Physiology ; Adaptation ; Growth ; Droop ; Monod
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In many experimental ecological studies on phytoplankton species the growth response of an organism to the prevailing environmental conditions have been studied. Curves relating specific growth rate (μ) to the external nutrient concentration (S) have been constructed to compare nutrient-limited growth of different species under steady state conditions. Microorganisms adapt their physiology to a certain limitation in order to optimize growth. Therefore the shape of the μ/S curve is closely related to the way a micoorganism adapts its physiology. To see how physiological adaptation and growth rate are interconnected to each other, both can be related to the internal concentration of the growth-limiting nutrient. How the growth rate is related to the internal nutrient concentration is presented in a mathematical equation. Many phytoplankton species during growth under different nutrient limitations show a linear relationship between μ and the reciprocal value of the internal nutrient content (= Yield). This was originally observed by Droop. The model presented here gives a theoretical explanation of this phenomenon.
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    Natural selection causing microsatellite divergence in wild emmer wheat at the ecologically variable microsite at Ammiad, Israel (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 985-999 
    Details
    ISSN: 1432-2242
    Keywords: Key words Natural selection ; Microecological diversity ; Microsatellites ; Adaptation ; T. dicoccoides ; Wild emmer wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Genetic diversity at 28 microsatellite loci was studied in a natural population of Triticum dicoccoides at the Ammiad microsite, north of the Sea of Galilee, Israel. This microsite was subdivided into four major habitats, North, Valley, Ridge and Karst, and further subdivided into nine subhabitats. The units thus defined showed strong and highly significant differentiation in ecological factors; in particular with respect to cover, proximity and height of rocks, and surface soil moisture after early rains. The results showed that allele distributions at microsatellite loci were nonrandom and associated with habitats. Significant genetic differentiation and variation in repeat number were found among subpopulations in the four major habitats and nine subhabitats. Habitat-specific and -unique alleles and linkage disequilibria were observed in the Karst subpopulation. The subpopulations dwelling in drier habitats and subhabitats showed higher genetic diversities at microsatellite loci. These results suggest that natural selection, presumably through aridity stress, acts upon microsatellite divergence predominantly on noncoding sequences, thereby contributing to differences in fitness.
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    Application of microsatellites in wheat (Triticum aestivum L.) for studying genetic differentiation caused by selection for adaptation and use (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 242-248 
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    ISSN: 1432-2242
    Keywords: Key words DNA markers ; Genetic diversity ; Agroecological area ; Quality ; Adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  For studying genetic differentiation caused by selection for adaptation and end-use, the allele frequencies of 42 microsatellites (MS), representative of the three wheat genomes, were analysed in a total of 60 wheat cultivars. The cultivars originate from three agroecological areas (AEAs) – Germany, Austria and Hungary – and represent equal numbers of ’quality wheats’ and ’feed wheats’ for each country. For the 42 loci, 202 alleles were detected using PAGE and silver staining. The average number of alleles per locus was 4.8, including four monomorphic loci. For 16 loci, null alleles were detected. Cluster analysis clearly differentiated the varieties according to the three AEAs and, within each AEA, into quality wheats from feed wheats. Analysis of variance revealed highly significant differences of distance data between AEAs as well as between quality groups. The correlation between genetic distance (GD) and pedigree data (coefficient of diversity, COD) was r s=0.45. The results have proven the excellent resolving power of MS in varietal differentiation, which arises through breeding under specific environmental conditions, and for different end-use.
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    Patterns and propensities in reproduction and growth of marine fishes (2000)
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    Ecological research 15 (2000), S. 101-106 
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    ISSN: 1440-1703
    Keywords: comparative ecology ; growth ; marine fish ; patterns ; reproduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: A number of strong regularities characterize certain very basic biological parameters in marine fishes. For example, the ovulated eggs of fish usually measure approximately 1 mm in diameter. The small, relatively uniform size of the eggs means that almost all fish larvae experience environmental variability at very similar scales, which itself establishes strong constraints for, and links between reproduction and recruitment. Additional constraints emerge from seawater being a poor medium for respiration, which establishes further linkages between growth and mortality. These constraints have produced strongly convergent features, and thence the patterns in reproduction and growth of marine fishes that are presented.
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    Effects of feeding rate on growth, feed utilizationand body composition of a tropical bagrid catfish (2000)
    Springer
    Aquaculture international 8 (2000), S. 19-29 
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    ISSN: 1573-143X
    Keywords: body composition ; catfish (Mystus nemurus) ; feeding rate ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A 10 week experiment was conducted to determine theeffects of feeding rate on growth, feed utilizationand body composition of the tropical bagrid catfish,Mystus nemurus. Catfish fingerlings with anaverage initial body weight of 12 g were fed apractical diet (36.2% protein, 16.5 kJ/g diet) atrates of 1, 2, 2.5, 3, 3.5, 4 or 5% of their bodyweight (BW) per day in two equal meals. Watertemperature was approximately 29 °C throughoutthe experiment. Percent weight gain increased almostlinearly with increasing feeding rates up to 2.5%BW/day beyond which no significant (P 〉 0.05)improvement in weight gain was observed. The specificgrowth rate of catfish fed rations of 1% BW/day was0.72%/day and this increased significantly to anaverage of 1.39%/day for catfish fed 2.5% BW/day andbeyond. Feed utilization did not differ significantly(P 〉 0.05) between fish fed 1.0 to 2.5%BW/day but decreased when rations were increased to3.0% BW/day and above. Feed efficiency ratio was0.79 for catfish fed 1.0% BW/day compared to a ratioof 0.27 for fish fed at 5% BW/day. Catfish fed 1.0%BW/day had the lowest condition factor, hepato- andviscerosomatic indices, but the highest carcass tobody weight ratio. These fish also had lowerproportions of whole body dry matter, lipid andprotein, carcass dry matter and lipid, and visceraldry matter and lipid than fish in other groups. Therewere no significant differences in either conditionindices or relative body composition of fish fedrations of 2.0 to 5.0% BW/day. Based on the growth,feed efficiency and body composition data obtained, afeeding rate of 2.5% BW per day is recommended forM. nemurus fingerlings raised at 29 °C.
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    Growth and feed utilisation of rainbow trout subjected to changes in feed lipid concentrations (2000)
    Springer
    Aquaculture international 8 (2000), S. 531-542 
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    ISSN: 1573-143X
    Keywords: feed intake ; growth ; protein utilisation ; proximate ; composition ; rainbow trout (Oncorhynchus mykiss)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Rainbow trout Oncorhynchus mykiss grew from 44 to 326 g in 96days when held at ∼12 °C. Fish were fed to satiation twice dailywith either high (L1: 30.8%, L2:31.4%) or lower-lipid feeds (C1: 18.8%,C2: 21.8%). Four feeding treatments were studied.Group C1C2 received feed C1 for 43 days(days 0–43) and C2 thereafter (days 44–96).Groups L1L2, L1C2 andC1L2 were subjected to dietary changes asindicated by the feed designations. After a short period of feedadaptation, fish ingested similar amounts of feed energy i.e., they ateless by weight of the lipid-rich (L) feeds. Feed lipid content did notaffect growth but fish fed L-feed had reduced feed conversion ratio(FCR) compared to fish fed C-feed (0.731 vs. 0.773) during days0–43 (P 〈 0.01). After 96 days,L1L2-fish were lower in body protein(15.8%) than the C1C2-fish (16.8%)(P 〈 0.01). L-feeds also tended to increase percentage lipidand reduce percentage whole body moisture and ash. A higher net proteinutilisation (NPU) was recorded in fish fed L-feeds (43.6%)compared to fish fed C-feeds (38.8%) in days 0–43(P 〈 0.05). This seemed to be the result of a lower proteinintake rather than a protein-sparing effect of feed lipid. Above athreshold value of approximately 6.5 mg protein eaten·g bodywtminus 1·day−1, NPU decreased.
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    Size heterogeneity can reduce aggression and promote growth in Atlantic salmon parr (2000)
    Springer
    Aquaculture international 8 (2000), S. 543-549 
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    ISSN: 1573-143X
    Keywords: aggression ; Atlantic salmon (Salmo salar) ; dominance ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Aggression in groups of 0+ Atlantic salmon (Salmo salar) was monitoredat weekly intervals in two tanks containing 100 fish each. Three 1 + salmonparr were added to one of these. After 5 weeks, fish weights were measuredin both tanks and the conditions reversed. At ten weeks, weights of fish inboth tanks were measured again. In both populations, levels of aggressionamong the smaller fish were significantly lower and growth ratessignificantly higher when the large fish were present. Although the largefish attacked the small ones, the rate at which they did so was an order ofmagnitude lower that the rate at which small fish attacked each other in theabsence of larger conspecifics. This raises the possibility that levels ofaggression among farmed salmon might be reduced by the addition of a fewlarge conspecifics.
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    Allelopathic Effects of Humus Phenolics on Growth and Respiration of Mycorrhizal Fungi (2000)
    Springer
    Journal of chemical ecology 26 (2000), S. 2015-2023 
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    ISSN: 1573-1561
    Keywords: Allelopathy ; growth ; phenolics ; Hebeloma ; Hymenoscyphus ; Picea abies ; Vaccinium myrtillus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Allelopathy due to humus phenolics is a cause of natural regeneration deficiency in subalpine Norway spruce (Picea abies) forests. If inhibition of spruce germination and seedling growth due to allelochemicals is generally accepted, in contrast there is a lack of knowledge about phenolic effects on mycorrhizal fungi. Thus, this work tested effects of a humic solution and its naturally occurring phenolics on the growth and respiration of two mycorrhizal fungi: Hymenoscyphus ericae (symbiont of Vaccinium myrtillus, the main allelochemical-producing plant) and Hebeloma crustuliniforme (symbiont of P. abies, the target plant). Growth and respiration of H. crustuliniforme were inhibited by growth medium with the original humic solution (−6% and −30%), respectively, whereas the same humic solution did not affect growth but decreased respiration of H. ericae (−55%). When naturally occurring phenolics (same chemicals and concentrations in the original humic solution) were added to the growth medium, growth of H. crustuliniforme was not affected, whereas that of H. ericae significantly increased (+10%). We conclude that H. ericae is better adapted to the allelopathic constraints of this forest soil than H. crustuliniforme and that the dominance of V. myrtillus among understory species could be explained in this way.
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    Genotype X environment interaction for bunch yield and its components in the oil palm (Elaeis guineensis, Jacq.) (1983)
    Springer
    Theoretical and applied genetics 64 (1983), S. 133-136 
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    ISSN: 1432-2242
    Keywords: Stability ; Adaptation ; Fitness trait ; Bunch yield ; Oil palm ; Elaeis guineensis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary There were significant differences between hybrids for number of bunches (NB), mean bunch weight (MBW) and fresh fruit bunch yield (FFB). For the hybrid population as a whole, significant hybrid X year (environment) effects were also observed for the two yield components and for yield per se. The linear component of the hybrid X year effect was also significant. There were highly significant and positive correlations between FFB, NB and MBW hybrid means and the regression co-efficients of the hybrid means on the environmental index. There were no significant associations between these means and mean square deviations from regression (s2d) for these traits.
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    URL: http://dx.doi.org/10.1007/BF00272720
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    Genotype x environment interaction in dairy cattle and its role in breeding programmes (1983)
    Springer
    Theoretical and applied genetics 66 (1983), S. 93-99 
    Details
    ISSN: 1432-2242
    Keywords: Lactation ; Milk yield ; Herd production ; Adaptation ; Dairy cattle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Eighty thousand, one hundred and eleven records of the Israeli dairy herdbook for the period of 1973–1977 were studied and examined to determine the existence of Genotype x Environment Interaction (GxE) as affecting milk yield in kg per day between calvings. Various quantitative measures of environment were used while the genotypes were evaluated as the average performance of each sire's daughters in a whole range of environments. When the environment was evaluated as level of production, the relative importance of the interaction was found to be very low. Furthermore, the linear dependence on the interaction of the individual sires with the environments was found to be inconsistent with time, meaning that no justification was found for using specific adaptation patterns of genotypes to these environments. When lactation number and given time periods were used as environments, significant interactions were found between genotypes and environments. Results of the analyses of Genotype x Lactation interaction imply that the interaction values, to a certain degree, confused the differences between the sires when based on first lactation records. We therefore conclude that the need exists to expand the basis of sire evaluation, including the addition of data on successive lactation periods beyond the first one. We maintain that the genetic characteristic for this phenomenon is the “lactations development” of a sire, i.e., the performance of its daughters during the different lactations. The “maturing rhythm” of a sire may be regarded as a dynamic expression of the genetic makeup controlling lactation development. Furthermore, the prospect of selecting sires of bulls for early or late maturing could provide a new tool for the dairy cattle breeder.
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    URL: http://dx.doi.org/10.1007/BF00265180
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    Analysis of the rye chromosome constitution and the amount of telomeric heterochromatin in the widely and narrowly adapted hexaploid triticales (1981)
    Springer
    Theoretical and applied genetics 60 (1981), S. 145-149 
    Details
    ISSN: 1432-2242
    Keywords: Triticale ; Rye ; Hexaploids ; Adaptation ; Chromosomal substitutions ; Modified chromosomes ; Telomeric heterochromatin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Investigations were made on the rye chromosome constitution and on the presence of telomeric heterochromatin in rye chromosomes of the 26 most widely and 24 most narrowly adapted triticale strains. Among widely adapted lines, 22 (85%) had a complete rye genome and four triticales only had chromosomal R-D genome substitutions. Twenty-three (96%) of the 24 most narrowly adapted triticales had substitutions between the chromosomes of the R and D genomes. The most widely adapted triticales accumulated fewer modified rye chromosomes in comparison to narrowly adapted lines. They had from one to three rye chromosomes with heterochromatic deletions: 46% of widely adapted lines had two modified rye chromosomes; 34% had three modified rye chromosomes, and 19% had a single modified rye chromosome. In widely adapted strains, the 1R, 4R, 5R and 6R modified chromosomes were observed; they were present in 80%, 73%, 50% and 11% of the cases, respectively. The most narrowly adapted triticales had from two to four modified rye chromosomes: 58% of the strains had three modified rye chromosomes; 29% had four modified rye chromosomes and 12% had two modified rye chromosomes. The modified 4R and 5R chromosomes were present in all of these lines. The 1R (modified), 6R (modified) and 7R (modified) were found in 83%, 25% and 16%, respectively, of the narrowly adapted strains. Results support the previous observations (Pilch 1980b) that a wide adaptation of hexaploid triticales is associated with the presence of the full potential of rye genome, and that it is independent of the amount of telomeric heterochromatin possessed by rye chromosomes.
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    Response of potato to rock phosphate applied in conjunction with pyrites or superphosphate (1981)
    Springer
    Potato research 24 (1981), S. 183-186 
    Details
    ISSN: 1871-4528
    Keywords: growth ; yield ; fertilizer mixes ; solubilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The growth of potato plants and yield of tubers were poor in plots fertilized with rock phosphate alone but the addition of pyrites so improved its efficacy that it outyielded superphosphate in one season. A mixture of rock phosphate and superphosphate, in equal proportions on a P basis, was found to be 85–93% as effective as suerphosphate in increasing tuber yield.
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    Effects of nickel on the rates of endocytosis, motility, and proliferation inTetrahymena and determinations on the cell content of the metal (1983)
    Springer
    Protoplasma 118 (1983), S. 140-147 
    Details
    ISSN: 1615-6102
    Keywords: Nickel ; Endocytosis ; Motility ; Proliferation ; Cellular nickel content ; Adaptation ; Tetrahymena pyriformis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary At concentrations above 1 mM, nickel has a dose-dependent effect on the rate of food vacuole formation in cells in the growth medium, proteose peptone (PP); total inhibition of endocytosis occurs within 10 minutes in 6mM nickel. However, only a 10 times lower concentration of nickel is tolerated by starved cells in an inorganic salt medium, a difference which may be ascribed to the high binding property of nickel to organic material. In the PP medium, nickel affects cell motility by increasing the rate of movement at a concentration of 1 mM, and by causing immobilization after 30 minutes in 6mM nickel; a spontaneous, partial recovery of cell motility is seen after 3 hours in 6 mM nickel. The effects of nickel on endocytosis and cell motility are reversible after removal of nickel. Cell proliferation continues at a reduced rate in 1 mM nickel, while only 1 1/2 cell doublings are achieved in 3 mM nickel during a 72-hour exposure, and no proliferation occurs in 6mM nickel, where an increasing cell mortality is observed after 12 hours. The cell content of nickel relates initially to the external concentration of the metal; however, cells in 1 mM nickel are capable of maintaining a constant content of the metal, whereas in 3 mM, the rate of accumulation is reduced after 3 hours, and cells in 6mM nickel accumulate the metal at a constant rate. All nickel-treated cells contain small refractive granules, previously proposed as representing an ion-regulating system, and the apparent adaption ofTetrahymena to the effects of nickel may be ascribed to such a regulation of the intracellular concentration of the metal.
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    Generation of jumping motion pattern for a hopping robot using genetic algorithm (2000)
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    Artificial life and robotics 4 (2000), S. 31-36 
    Details
    ISSN: 1614-7456
    Keywords: Genetic algorithm ; Hopping robot ; Adaptation ; Pattern generator
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract This paper describes an application of genetic algorithm to generate a jumping motion pattern for a hopping robot. A central pattern generator is used to generate the motion pattern. The tuning parameters of the central pattern generator are regarded as genes and adjusted by the genetic algorithm, so that the hopping robot can jump continuously to the reference height with the minimum force. To realize online tuning of the parameters, new genetic operations such as few individuals, quick estimation, instant selection, and intentional mutation are introduced. The experimental results demonstrate the effectiveness of the proposed scheme.
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    Metabolism of Poly-β-Hydroxybutyric Acid in Yersinia pseudotuberculosis and Listeria monocytogenes Cultivated at Different Temperatures (2000)
    Springer
    Microbiology 69 (2000), S. 652-654 
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    ISSN: 1608-3237
    Keywords: poly-β-hydroxybutyric acid ; Yersinia pseudotuberculosis ; Listeria monocytogenes ; temperature ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A comparative investigation of the intracellular content of poly-β-hydroxybutyric acid showed that Yersinia pseudotuberculosis strains accumulated, on the average, lower amounts of this reserve substance than Listeria monocytogenes strains. The intracellular pool of poly-β-hydroxybutyric acid was responsible for the growth of the bacteria at low temperatures (4–6°C) in the absence of any exogenous carbon and energy source.
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    On the Nature of the Three-Phase Response of Scenedesmus quadricauda Populations to the Action of Imazalil Sulfate (2000)
    Springer
    Russian journal of plant physiology 47 (2000), S. 772-778 
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    ISSN: 1608-3407
    Keywords: Scenedesmus quadricauda ; growth ; cell size ; photosynthetic activity ; imazalil sulfate ; three-phase dose response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three-phase dose responses of biological systems of different levels of organization are often called “paradoxical” because the biological effects are clearly manifested under low- and high-intensity treatments, but are absent during moderate-strength treatments. In this work, we found anomalous changes in the cell number of a green alga Scenedesmus quadricauda (Turp.) Breb. grown in the presence of the fungicide imazalil sulfate. At low imazalil concentrations (2.5 × 10–9–2.5 × 10–6 M), the slow increase in the cell number as compared to an untreated culture was not related to cell death. As seen by the dynamics of the population structure and cell functional characteristics (photosynthesis, thermal stability of photosynthetic membranes, etc.), the decrease in the growth rate at low concentrations of imazalil (2–10 × 10–9 M) was due to a long-term arrest of cell division in a fraction of the cell population rather than to a decrease in the rate of division. The absence of a toxic effect or even a slight stimulation of culture growth at moderate concentrations (0.05–1.25 × 10–6 M) was due to the resumption of cell division after a temporal cessation. At these concentrations, imazalil induced cell stress and adaptive elevation of cell tolerance to the fungicide (acclimation). Cell death was observed only at a high fungicide content in the medium (6.25 × 10–6 and higher). Thus, the three-phase (bimodal) dose response corresponds to two regimes (steady-states) of cell functioning which differ in cell sensitivity to external stimuli. The low-sensitivity state, which is characteristic of cells that have experienced stress, is likely to be the state known as “hormesis.”
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    Adaptational changes of plastids in the leaves ofLigustrum ovalifolium Hassk. var.aureum at different light intensities (1984)
    Springer
    Protoplasma 122 (1984), S. 132-137 
    Details
    ISSN: 1615-6102
    Keywords: Adaptation ; Light intensity ; Ligustrum ; Plastids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The capacity of adaptation and the range of adjustment to different light conditions in fully expanded mutant leaves were studied on an aurea variety of privet (Ligustrum ovalifolium Hassk. var.aureum). Whenever the light conditions are altered leaves respond immediately. Although adaptational changes in leaf thickness are not possible, the change in colour, as well as changes in pigment concentrations take place within several days. With increasing light intensity there is a marked decline in chlorophyll concentration and the carotenoid yield becomes much higher. Under low light conditions the chlorophyll content is high, while the carotenoid concentration drops significantly. The mutant chloroplasts from green leaves always have a well developed thylakoid system. The only difference between young green leaves (DG1) and older regreened ones (DG2) is in the number of thylakoids per granum (grana in older leaves consist of more thylakoids), while the stacking degree of thylakoids remains about the same (74 and 77% respectively). Depending on the previous light conditions fine structure of plastids in yellow leaves differs considerably. Young yellow leaves (Y0) contain plastids with longitudinal arrays of dilated thylakoids and prothylakoid bodies occasionally. Plastids from primarily green leaves which turned yellow afterwards in strong sunlight (Y1) are characterized by thylakoids densely packed into cup-shaped stacks, or large vesicles originating from dilated thylakoids. The stacking degree of thylakoids in sun exposed yellow leaves (determined only in Y0 leaves) is extremely low and reaches only 29%.
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    Influence of CO2, light and watering on growth of Nostoc flagelliforme mats (2000)
    Springer
    Journal of applied phycology 12 (2000), S. 185-189 
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    ISSN: 1573-5176
    Keywords: blue-green alga ; cyanobacterium ; carbon dioxide ; culture ; growth ; Nostocflagelliforme ; rehydration, watering
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The terrestrial blue-green alga (cyanobacterium), Nostoc flagelliforme, was cultured in air at variouslevels of CO2, light and watering to see theireffects on its growth. The alga showed the highestrelative growth rate at the conditions of highCO2 (1500 ppm), high light regime (219–414μmol m-2s-1) and twice daily watering,but the lowest rate at the conditions of low light(58–114 μmol m-2s-1) and daily twicewatering. Increased watering had little effect ongrowth rate at 350 ppm CO2, but increased byabout 70% at 1500ppm CO2 under high lightconditions. It was concluded that enriched CO2could enhance the growth of N. flagelliformewhen sufficient light and water was supplied.
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    Phenological spread in plants: A result of adaptations to environmental stochasticity? (1980)
    Springer
    Plant ecology 43 (1980), S. 83-86 
    Details
    ISSN: 1573-5052
    Keywords: Adaptation ; Colonization ; Environmental stochasticity ; Phenology ; Weather variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Plant species co-inhabiting a given geographical region often have distinetly different times of flowering. It is shown that such phenological spread, duc to short-term stochastic variation in weather variables, relaxes competition for empty sites to be colonized by diaspores. For sufficiently large spreads stable coexistence becomes possible. The applicability of the proposed hypothesis to the observed instances of phenological spread is discussed and shown to extend beyond that of other current theories.
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    Life history comparisons of Daphnia obtusa from temporary ponds, cultured with a low-quality food (2000)
    Springer
    Aquatic ecology 34 (2000), S. 19-27 
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    ISSN: 1573-5125
    Keywords: adaptation ; fitness ; food quality ; growth ; reproduction ; temporary ponds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Temporary pond Daphnia flourish on relatively poor-quality food, suggesting adaptation to stringent temporary pond conditions. We conducted laboratory life history experiments on populations of Daphnia obtusa from a shaded woodland temporary pond (short hydroperiod, dystrophic) and an open farmland temporary pond (long hydroperiod, eutrophic), and compared a suite of physical/chemical conditions in the ponds to evaluate habitat conditions. We hypothesized that the shaded woodland pond population would be more fit in terms of life history variables for individuals (age and size at first reproduction, mean brood size, mean number of neonates) and populations (generation time, net reproductive rate R 0, and intrinsic reproductive rate r) given a standard, low-quality food (trout chow and yeast). Life history traits of woodland pond animals were mixed, relative to farm pond animals, and consistent with bet-hedging for an unpredictable habitat. Values of life history traits rivaled or exceeded those of other studies using phytoplankton as food, and were influenced by the pond water used for our study. Life histories clearly differ among local and regional temporary pond Daphnia obtusa populations, and should be valuable for examining the relative influences of local selection and metapopulation dynamics on population structure.
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    Responses of Porphyra linearis (Rhodophyta) to environmental factors under controlled culture conditions (2000)
    Springer
    Journal of applied phycology 12 (2000), S. 535-542 
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    ISSN: 1573-5176
    Keywords: desiccation ; growth ; growth model ; inorganic carbon ; nutrients ; photoperiod ; photosynthesis ; pigments ; Porphyra linearis ; PPF ; respiration ; temperature ; water velocity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of environmental parameters on the growthof Porphyra linearis gametophytes was examinedunder controlled conditions, and related to themultilinear regression growth model recently developedfor this seaweed under coastal conditions in theeastern Mediterranean. Growth chambers, a gradienttable, special culture devices and analytical methodswere combined for this culture study.The major factors significantly controlling thegrowth rate of the P. linearis gametophytein glass dishes were: photoperiod, temperature, agein culture, photosynthetic photon flux (PPF), salinityand water dynamics. Maximal growth occurred underdaylength of 12 h, medium temperature (15–20 °C), low PPF (70–140 μmol photon m-2s-1), ambient salinity (30–40 ppt), 1–3 h ofdaily air exposure, and water velocity of 4 cm s-1.Photosynthesis and respiration rates weredominantly affected by daylength and temperature,while the concentration of pigments was dominantlyaffected by PPF and temperature.These conditions correspond well to the optimalnatural growth environment of this local species andare in agreement with the optimum estimated throughthe recently developed outdoor mathematical growthmodel.
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    Differential growth of crayfish Procambarus alleni in relation to hydrological conditions in marl prairie wetlands of Everglades National Park, USA (2000)
    Springer
    Aquatic ecology 34 (2000), S. 389-395 
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    ISSN: 1573-5125
    Keywords: crayfish ; Procambarus alleni ; growth ; Florida Everglades ; hydroperiod
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Environmental conditions influence crustacean growth by affecting molt intervals and incremental increases in length and weight. In the seasonally-flooded marl prairie wetlands of eastern Everglades National Park, U.S.A., hydropattern exerts considerable influence on aquatic primary productivity, and so may influence the availability of food resources for higher trophic levels. The seasonal hydroperiod has been drastically altered by anthropogenic factors, but the impacts on the aquatic community are not well known. We studied whether differences in growth of crayfish Procambarus alleni could be detected in habitats with different hydroperiods. We first described growth patterns based on incremental increases in length and weight of crayfish on a high protein diet in the laboratory. Regression analyses indicated that growth patterns in males and females were similar. Although the intermolt period increased with age, the proportional increases in length and weight were similar through successive molts. The relationship between length and weight of crayfish was best described by a power equation for allometric growth. We then compared growth curves for crayfish subpopulations from different areas of the marl prairie. In habitats with the longest hydroperiods, crayfish weight-at-size was not significantly different from that in laboratory crayfish on the high protein diet. However, weight gain per unit increase in length in short hydroperiod sites was significantly less than in long hydroperiod sites or in the laboratory. These results indicate that crayfish productivity may be associated with hydroperiod in these stressed wetlands, and this may contribute to observed source-sink population regulation.
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    Adrenergic mechanisms of regulation of motor response in early postnatal rats (1984)
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    Bulletin of experimental biology and medicine 98 (1984), S. 1159-1161 
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    ISSN: 1573-8221
    Keywords: motor response ; growth ; catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1007/BF00804282
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    Literature growth in pharmacokinetics (1982)
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    Journal of pharmacokinetics and pharmacodynamics 10 (1982), S. 335-348 
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    ISSN: 1573-8744
    Keywords: pharmacokinetics ; bioavailability ; growth ; literature growth ; logistic function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The literature growth in pharmacokinetics and bioavailability between the years 1964 and 1980 is analyzed. During much of this period, the literature doubled approximately every 1.6 years. However, during the period 1978–1980, little or no growth was observed. During the period 1950–1967, the total chemical literature increased exponentially with a half-life of 8.28 years; between 1968 and 1980, the half-life was 12.4 years. Thus, the pharmacokinetic literature increased at a much more rapid pace than did the total chemical literature in general. The subject of growth is considered in a general context, particularly as influenced by psychological, sociological, political, and economic factors. It is concluded that while mathematical functions may adequately describe past literature trends, they have little if any utility in predicting future trends in specific research areas such as pharmacokinetics.
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    Effects of air emersion on survival and growth of hatchery rearedgreat scallop spat (2000)
    Springer
    Aquaculture international 8 (2000), S. 159-168 
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    ISSN: 1573-143X
    Keywords: emersion ; growth ; Pecten maximus ; scallop spat ; survival ; transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Scallop spat production normally requires transfer between growthsystems. Simulated transport experiments were carried out in April, June,December and February to evaluate effects of transport time on greatscallop (Pecten maximus) spat growth and survival. The spat (1.7–1.8 mm in shell-height and 21–25 µg ash free dry weight [AFDW]) wereheld in moist coffee filters at a temperature of 10 °C for up to 24 h,before being replaced into sieves in rearing tanks at 15 °C. The studyshowed that by increasing air emersion time, survival and growthdecreased. No significant difference in the results between 0 and 4 h of airemersion was found, while the effects after 12 and 24 h differed betweenspat groups. Survival and growth rates showed seasonal differences. Meansurvival was 35–71% in April and 77–99% from June to February. In Junemean growth rates attained were 115–128 µm shell-height and 15–18µg AFDW per day compared with 49–69 µm and 3.8–7.0 µgper day for the other spat groups. Great scallop spat may survive atransfer time of 24 h, but transportation for longer than 12 h is notrecommended if subsequent high survival and growth rates are to beensured.
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    Growth and mortality of the king scallop grown in suspended culture in Malaga, Southern Spain (2000)
    Springer
    Aquaculture international 8 (2000), S. 207-225 
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    ISSN: 1573-143X
    Keywords: growth ; mortality ; Pecten maximus ; suspended culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Growth and mortality of the king scallop, Pecten maximus, werecompared when grown in cages and by ear hanging in suspended culturein Fuengirola, Malaga, in southern Spain. Seed (juveniles) used in theexperiment was collected in September 1997 that had settled on collectorsin April-June, of that year. Culture in suspended cages began in January1998 when the seed measured 42.7 (3.3) mm shell height and ended inFebruary 1999. Significantly faster growth was found at a minimum culturedensity (16 scallops/cage) than at two other densities (24 and 36scallops/cage). Depth (1, 5 and 10 m from the bottom) influenced growth,poorest growth occurred closest to the bottom. Under optimum growingconditions, 16 scallops/cage suspended 10 m from the bottom, scallops grewto 10 cm shell length (legal size) by February 1999.In ear hanging culture, ropes were moored in April (51.3 (4.5) mm),June (58.2 (4.5) mm) and November 1998 (64.3 (4.9) mm).Initially, rapid shell growth was observed in all three cultures.Subsequently, the shells became covered with barnacles, Balanus sp.,that possibly caused total mortality of the April culture and led to highmortalities in the two other cultures.
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    Effects of larger fish and size grading on growth and size variation in fingerling silver perch (2000)
    Springer
    Aquaculture international 8 (2000), S. 391-401 
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    ISSN: 1573-143X
    Keywords: growth ; silver perch (Bidyanus bidyanus) ; size grading ; size variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This study presents two experiments addressing growth and size variation in fingerling silver perch (Bidyanus bidyanus. In the first experiment, fish close to mean population size were raised either in the presence or absence of five larger fish for 60 days. Mean specific growth rate (SGR) and increases in the coefficient of variation and skewness were lower in the presence of larger fish, indicating a negative effect of large fish on the growth of smaller ones. In the second experiment, fingerlings were graded into groups smaller and larger than the median size of the population and raised in size-sorted groups of 60 large or small fish and mixed groups of 30 fish of each size category, for 60 days. There was no difference in mean SGR among groups, nor between the mixed group ad the weighted mean of the small and large groups. Biomass gain was higher in the mixed groups than in the weighted small-and-large groups, probably due to a slightly lower survival in the groups comprised of large fish. The fact that the effect of large fingerlings on the growth of smaller ones was evident in the first, but not the second, experiment may be attributed to higher size disparity between large and small fingerlings in the first experiment.
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    Partial or total replacement of fish meal byplant protein affects gonadal development and plasma17 β-estradiol levels in female Nile tilapia (2000)
    Springer
    Aquaculture international 8 (2000), S. 299-313 
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    ISSN: 1573-143X
    Keywords: 17 β-estradiol ; fish meal ; gonadal development ; growth ; Nile tilapia (Oreochromis niloticus) ; plant proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This study was conducted to evaluate theeffect of plant protein‐based diets on gonadaldevelopment and plasma 17 β-estradiol (E2) levelin female Nile tilapia Oreochromis niloticus.Fish with a mean body weight of 6.7 (0.1) g were fedfour different diets with the same digestible protein(DP) and digestible energy (DE) containing gradedlevels of a mixture of plant ingredients as partial ortotal replacement of fish meal protein for 20 weeks.The control diet (D0) was based on fish meal, twodiets containing 33% (D33) and 66% (D66) of plantprotein, and one diet containing only plant protein(D100). Fish were sampled at 12 and 20 weeks. Nosignificant differences were found in different stagesof oocyte development and plasma E2 levels betweentilapia fed diets D0 and D100 at 12 weeks. Eight weekslater tilapia fed diet D0 showed a higher (P 〈 0.05)level of E2 than the D100 group. This difference andthe reduced proportion of vitellogenic and matureoocytes demonstrated that diets containing only plantprotein are less efficient in terms of tilapia growthand consequently ovarian development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009217310464
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    Growth performance of pink dentex as compared to four other sparids reared in marine cages in Croatia (2000)
    Springer
    Aquaculture international 8 (2000), S. 455-461 
    Details
    ISSN: 1573-143X
    Keywords: floating cages ; growth ; pink dentex (Dentex gibbosus) ; sparids (Dentex dentex, Sparus aurata, Spondyliosoma cantharus, Diplodus puntazzo)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009276204516
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    The effect of photoperiod, tank colour and light intensity on growth of larval haddock (2000)
    Springer
    Aquaculture international 7 (2000), S. 369-382 
    Details
    ISSN: 1573-143X
    Keywords: growth ; haddock (Melanogrammus aeglefinus) ; larvae ; light intensity ; photperiod ; tank colour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In two separate experiments, haddock (Melanogrammus aeglefinus) larvae were raised under different photoperiods (24L : 0D or 15L : 9D), or different combinations of tank colour (black or white) and light intensity (1.1 μmol s−1 m−2 or 18 μmol s−1 m−2). Growth (0.8% day−1 in standard length; 2.9% day−1 in body area) and survival (2%) were not significantly different between photoperiod treatments after 35 days. Larval survival was greater in white versus black tanks after 41 days (2% versus l%, respectively). Growth of larvae was impaired in black tanks at low (1.1 μmol s−1 m−2) light intensity (0.8% day−1 in standard length and 2.2% day−1 in body area versus 1.1% day 21 in standard length and 3.1% day−1 in body area, for all other treatments). Transmission and reflection of light was low in black tanks at low incident light, and there was very little upwelling light. The resultant poor prey to background contrast probably resulted in larvae being unable to consume sufficient food to sustain a level of growth comparable to that in other treatments.
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    URL: http://dx.doi.org/10.1023/A:1009204909992
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    Influence of season, initial size, depth, gear type and stocking density on the growth rates and recovery of sea scallop, Placopecten magellancius, on a farm-based nursery (2000)
    Springer
    Aquaculture international 8 (2000), S. 183-206 
    Details
    ISSN: 1573-143X
    Keywords: bivalve ; fouling ; growth ; Newfoundland ; nursery ; sea scallop (Placopecten magellanicus) ; spat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Hatchery-reared sea scallop (Placopecten magellanicus) spat weremonitored for growth and recovery in three experiments to determine themost suitable system for nursery culture. In Experiment I, four size classesof nursery-sized spat held at two depths from October to July exhibiteddeclining growth rates over the winter period and increased growth ratesin the spring. Overall, season, depth and initial size had a significantinfluence on the absolute and specific growth rates of scallops. Recovery,defined as number of scallops remaining after mortality and loss of spatthrough gear mesh, was influenced by season and initial size, but notdepth. Scallops in the 3.0 mm+ size class had higher growth rates andrecovery than those in the 1.4–1.6 mm, 1.7–1.9 mm and 2.0–2.9 mm sizeclasses. In Experiment II, two gear types containing similar size spat werecompared. Growth rates were significantly higher in 3.0 mm pearl nets thanin 3.0 mm collector bags, although recovery was similar between the twoequipment types. Experiment III, two stocking densities of nursery-sizedspat were compared in collector bags. Neither growth rate nor recoverywere significantly different for the two densities (2600 and 5200spat/collector bag) tested. Overall, these studies indicated that importantparameters for optimizing the growth and recovery of scallops in a farm-based nursery system include season, initial spat size, deployment depthand gear type.
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    URL: http://dx.doi.org/10.1023/A:1009298631346
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    Growth effects in Arctic charr reared in cold water: Feed frequency, access to bottom feeding and stocking density (2000)
    Springer
    Aquaculture international 8 (2000), S. 381-389 
    Details
    ISSN: 1573-143X
    Keywords: Arctic charr (Salvelinus alpinus) ; growth ; low temperature ; stocking density ; time restricted feeding,/kwd〉
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of time restricted feeding, possibility of bottomfeeding and stocking density on the growth of Arctic charr(Salvelinus alpinus L.) were examined in fish held at lowtemperature (〈2 °C). Fish fed for a restricted time (1 h) hadsignificantly (p 〈 0.05) lower specific growth rate (0.15 vs0.32% per day) than those fed the same ration over an extendedtime period (12 h). Increasing stocking densities had a positive andsignificant effect (p 〈 0.05) on growth with SGR increasing from 0.27to 0.52% per day at 2–30 kg m-3. Fish withaccess to feed on the tank floor had a significantly higher (p 〈0.05) growth rate (0.3 vs 0.13% per day) than those without thepossibility to feed from the bottom. When fish were held underconditions without access to the bottom a doubling of the feed rationdid not result in a significant (p 〉 0.05) increase in growth rate(0.13 vs 0.12%percnt; per day).
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    URL: http://dx.doi.org/10.1023/A:1009235130015
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    Effect of high protein rice on nitrogen retention and growth of preschool children on a rice-based diet (1981)
    Springer
    Plant foods for human nutrition 31 (1981), S. 97-108 
    Details
    ISSN: 1573-9104
    Keywords: children ; growth ; high protein rice ; nitrogen retention ; rice-based diet
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effect of high protein milled rices (IR480-5-9 and IR2153-338-3, 10% protein) on the nitrogen retention and growth of preschool Indian children was assessed in two feeding trials in a residential home. The children were offered, ad libitum, a rice-based diet in four meals daily without vitamin and mineral supplement. The children in the experimental group were given the high protein rice; those in the control group were given a local rice (7% protein). The groups had similar percent apparent digestibility and retention of dietary nitrogen. Statistically significant differences in increase in height and weight between the two groups were not consistently observed at the end of 4.5 to 5 months or 1 year. Possible factors contributing to these results are discussed.
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    URL: http://dx.doi.org/10.1007/BF01094034
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  • 56
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    Patterns of trait variation in the diploid wheats (Triticum, Aegilops) and the tetraploid speciesTriticum diccocoides (1983)
    Springer
    Plant systematics and evolution 143 (1983), S. 257-275 
    Details
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Aegilops ; Triticum ; T. diccocoides ; wheat ; Adaptation ; trait variation ; factor analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Eighteen earliness and morphological traits were examined in from 2 to 14 lines each of 10 diploid members of the wheat complex,Triticum-Aegilops, and 15 lines of the tetraploid speciesTriticum diccocoides. In general, earliness traits have the greatest relative between line vs. within line variation of all the traits examined. Within species, earliness traits are the principle set of characters around which evolve between line trait differences, one of the most important oich is leaf dimensions. At the genus level, earliness traits are independent of leaf dimensions and plant height characters. Thus, the pattern of evolution at the genus level is different from that exhibited in each of the species. Biological and evolutionary implications of these findings are discussed.
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    URL: http://dx.doi.org/10.1007/BF00986608
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  • 57
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    Finite Element Simulation of Location- and Time-Dependent Mechanical Behavior of Chondrocytes in Unconfined Compression Tests (2000)
    Springer
    Annals of biomedical engineering 28 (2000), S. 318-330 
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    ISSN: 1573-9686
    Keywords: Biphasic ; Poroelastic ; Cartilage ; Finite element analysis ; Cell mechanics ; Tissue growth ; Adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract Experimental evidence suggests that cells are extremely sensitive to their mechanical environment and react directly to mechanical stimuli. At present, it is technically difficult to measure fluid pressure, stress, and strain in cells, and to determine the time-dependent deformation of chondrocytes. For this reason, there are no data in the published literature that show the dynamic behavior of chondrocytes in articular cartilage. Similarly, the dynamic chondrocyte mechanics have not been calculated using theoretical models that account for the influence of cell volumetric fraction on cartilage mechanical properties. In the present investigation, the location- and time-dependent stress-strain state and fluid pressure distribution in chondrocytes in unconfined compression tests were simulated numerically using a finite element method. The technique involved two basic steps: first, cartilage was approximated as a macroscopically homogenized material and the mechanical behavior of cartilage was obtained using the homogenized model; second, the solution of the time-dependent displacements and fluid pressure fields of the homogenized model was used as the time-dependent boundary conditions for a microscopic submodel to obtain average location- and time-dependent mechanical behavior of cells. Cells and extracellular matrix were assumed to be biphasic materials composed of a fluid phase and a hyperelastic solid phase. The hydraulic permeability was assumed to be deformation dependent and the analysis was performed using a finite deformation approach. Numerical tests were made using configurations similar to those of experiments described in the literature. Our simulations show that the mechanical response of chondrocytes to cartilage loading depends on time, fluid boundary conditions, and the locations of the cells within the specimen. The present results are the first to suggest that chondrocyte deformation in a stress-relaxation type test may exceed the imposed system deformation by a factor of 3–4, that chondrocyte deformations are highly dynamic and do not reach a steady state within about 20 min of steady compression (in an unconfined test), and that cell deformations are very much location dependent. © 2000 Biomedical Engineering Society. PAC00: 8719Rr, 8717Aa, 0270Dh
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    URL: http://dx.doi.org/10.1114/1.271
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    The effects of external potassium and magnesium concentrations on the magnesium and potassium inflow rates and growth of micropropagated cherry rootstocks, “F.12/1” (Prunus avium L.) and “Colt” (Prunus avium L.) × Prunus pseudocerasus L.) (2000)
    Springer
    Plant and soil 225 (2000), S. 73-82 
    Details
    ISSN: 1573-5036
    Keywords: growth ; inflow ; magnesium ; potassium ; (Prunus)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects (and interaction) of two solution concentrations of Mg (50, 500, μM) and two of K (250, 4250 μM) on the growth of micropropagated plants of “F. 12/1” and “Colt” were investigated using a flowing solution culture system. Magnesium inflow and growth of “Colt” and “F. 12/1” were inhibited to a similar extent by an increased concentration of K in the nutrient solution. However, the consequences of this inhibition were different. Reduced inflow of Mg in “F. 12/1” caused Mg deficiency symptoms at high and low concentrations of K, whereas this only occurred with a combination of high K concentration and low Mg concentration in “Colt”. The distribution of dry matter within the plant was significant in determining susceptibility to Mg deficiency. Since “F. 12/1” has a smaller root:shoot ratio than Colt it is unable to sustain the same concentration of Mg in leaves as “Colt” irrespective of external K concentration. The molar ratio of K:Mg in soil solutions should remain 〈8.5:1 in order to ensure maximum growth of “F. 12/1” and “Colt”.
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    Nitrate production in the rhizosphere of Plantago species (1981)
    Springer
    Plant and soil 61 (1981), S. 43-52 
    Details
    ISSN: 1573-5036
    Keywords: Adaptation ; Allelopathy ; Ecophysiology ; Grassland ; Plantago ; Nitrate production ; Nitrate reductase ; Nitrate uptake ; Nitrification ; Nitrifying bacteria ; Rhizosphere ; Root environment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The production of nitrate in an old established dune grassland soil and its uptake by plants was studied by comparing amounts of mineral nitrogen and numbers of nitrifying bacteria in the rhizosphere on the one hand, and on the other accumulated nitrate and levels of nitrate reductase (NaR) of individual plants of three Plantago species,i. e., P. major, P. lanceolata andP. coronopus. For these three Plantago species andP. media basal levels of NaR in the absence of nitrate were determined in plants grown in culture solutions. The basal NaR levels ofP. major andP. media (species occurring on nutrient-rich soils) were significantly higher than those ofP. lanceolata andP. coronopus (species found on nutrient-poor soils). NaR activity increased in the presence of nitrate and was suppressed by ammonium. From the numbers of nitrifying bacteria in the rhizosphere and NaR activity in the leaves it was concluded that nitrate was produced in the root environments of the three Plantago species and that the compound was taken up by the plants. NaR activities and numbers of nitrifying bacteria were higher for individuals ofP. major than for those ofP. lanceolata andP. coronopus. No correlation was found between the ammonium levels and the numbers of nitrifying bacteria in the soil, and no indications of inhibition of nitrifying bacteria in the rhizosphere were obtained. For individuals ofP. lanceolata a correlation was found between the numbers of nitrifying bacteria in the soil and NaR activity in the leaves. The results are discussed in relation to the ecological habitats of the three species.
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    URL: http://dx.doi.org/10.1007/BF02277361
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    Obtention d'un mutant deRhizobium meliloti adapté aux cultures de luzerne en terres acides (1981)
    Springer
    Plant and soil 60 (1981), S. 99-110 
    Details
    ISSN: 1573-5036
    Keywords: Adaptation ; Luzerne ; Mutant ; Rhizobium meliloti ; Terres acides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Resume Un mutant acido-tolérant deR. meliloti a été isolé. Le caractère de résistance en milieu acide n'a pas été obtenu par adaptation sur des milieux de plus en plus acides mais par mutagenèses successives provoquées par la N-méthyl-N'nitroso-N-nitrosoguanidine (NTG) et sélection sur milieu acide de façon à rendre stable le caractère acido-tolérant. Ce mutant acide présente la propriété de se développer plus lentement que la souche sauvage sur milieu pauvre. Ceci ne l'empêche pas de présenter sensiblement la même efficience que cette dernière à pH voisin de la neutralité en milieu synthétique. L'étude comparative de l'efficience de la souche parentale et de la souche mutée sur la luzerne cultivée en terre acide est rendue difficile du fait de la présence de nitrates qui réduit la nodulation et inhibe l'action de la nitrogénase: par épuisement, en effectuant une culture dense de luzerne sur cette terre, il est possible de mettre en évidence ensuite l'activité symbiotique importante à pH 5,9 du mutant par rapport à la souche sauvage.
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    Water relations, ethylene production, and morphological adaptation ofFraxinus pennsylvanica seedlings to flooding (1984)
    Springer
    Plant and soil 77 (1984), S. 183-192 
    Details
    ISSN: 1573-5036
    Keywords: Adaptation ; Adventitious roots ; Ethylene ; Flooding ; Fraxinus pennsylvanica ; Lenticels ; Turgidity ; Water potential ; Water relations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Fraxinus pennsylvanica Marsh. seedlings that were 150 days old adapted well to flooding of soil with stagnant water for 28 days. Early stomatal closure, followed by reopening as well as hypertrophy of lenticels and formation of adventitious roots on submerged portions of stems appeared to be important adaptations for flood tolerance. Leaf water potential (ψ1) was consistently higher in flooded than in unflooded seedlings, indicating higher leaf turgidity in the former. This was the result of (1) early reduction in transpiration associated with stomatal closure, and (2) subsequently increased absorption of water by the newly-formed adventitious roots as stomata reopened and transpiration increased. Waterlogging of soil was followed by large increases in ethylene content of stems, both below and above the level of submersion. Formation of hypertrophied lenticels and adventitious roots on flooded plants was correlated with increased ethylene production. However, the involvement of various compounds other than ethylene in inducing morphological changes in flooded plants is also emphasized.
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    Dynamics of biomass and N accumulation of alfalfa under three N fertilization rates (2000)
    Springer
    Plant and soil 219 (2000), S. 177-185 
    Details
    ISSN: 1573-5036
    Keywords: alfalfa ; growth ; Medicago sativa L. ; nitrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The dynamics of biomass and N accumulation following defoliation of alfalfa and the application of N fertilization has rarely been studied under field conditions, particularly in the seeding year. Our objectives were to determine the effect of N fertilization on the dynamics of biomass and N accumulation during the first regrowth of alfalfa in the seeding year, and to determine if a model describing critical N concentration developed for established stands could be used in the seeding year. In two separate experiments conducted in 1992 and 1993, the biomass and N accumulation of alfalfa grown with three N rates (0, 40 and 80 kg N ha-1) were determined weekly. Maximum shoot growth was reached with 40 kg N ha-1 in 1992, and maximum shoot growth was not reached with the highest N fertilization rate in 1993. Nitrogen fixation, root N reserves and soil inorganic N uptake when no N was applied were, therefore, not sufficient to ensure non-limiting N conditions, particularly when growth rates were the highest between 14 to 21 d after defoliation. Nitrogen fertilization increased shoot biomass accumulation in the first 21 d of regrowth, biomass partitioning to the shoots and shoot and taproot N concentrations. The model parameters of critical N concentration developed by Lemaire et al. (1985) for established stands of alfalfa were not adequate in the seeding year. The N requirements per unit of shoot biomass produced are greater in the seeding year than on established stands, and this was attributed to a greater proportion of leaves in the seeding year.
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    Interaction effects of phosphorus and zinc on photosynthesis, growth and yield of dwarf bean grown in two environments (2000)
    Springer
    Plant and soil 220 (2000), S. 219-228 
    Details
    ISSN: 1573-5036
    Keywords: growth ; light intensity ; Phaseolus vulgaris L. ; phosphorus–zinc interaction ; photosynthesis ; yield ; zinc deficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two experiments were conducted in a factorial combination of three Zn levels (0, 10 and 40 mg Zn kg-1 soil) and two P levels (0 and 200 mg P kg-1 soil). Experiment 1 was carried out during winter in a heated glasshouse, and experiment 2 during summer under a rain shelter. Plants of dwarf bean (Phaseolus vulgaris L., cv. Borlotto nano) were grown in pots filled with sandy soil. In both experiments, leaf Zn concentration was reduced by the addition of P to plants grown at low Zn supply. However, leaf Zn concentration lower than the critical level was observed only during experiment 2, and the main effects of low Zn were reductions of internode length, light use efficiency and maximum photosynthetic rate. In plants with leaf Zn concentration lower than the critical level, saturating irradiance levels fell from ∼1000 μmol m-2 s-1 PPFD to ∼300–400 μmol m-2 s-1 PPFD. Reduction of net photosynthesis was observed from the beginning of flowering and led to decreased seed production.
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    Physiological, morphological, and growth responses ofPlatanus occidentalis seedlings to flooding (1982)
    Springer
    Plant and soil 66 (1982), S. 243-255 
    Details
    ISSN: 1573-5036
    Keywords: Adaptation ; Adventitious roots ; Ethylene ; Flooding ; Growth of seedlings ; Lenticels ; Platanus occidentalis ; Stomatal aperture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Flooding ofPlatanus occidentalis L. seedlings for up to 40 days induced several changes including early stomatal closure, greatly accelerated ethylene production by stems, formation of hypertrophied lenticels and adventitious roots on submerged portions of stems, and marked growth inhibition. Poor adaptation ofPlatanus occidentalis seedlings to soil inundation was shown in stomatal closure during the entire flooding period, inhibition of root elongation and branching, and death of roots. Some adaptation to flooding was indicated by (1) production of hypertrophied lenticels which may assist in exchange of dissolved gases in flood water and in release of toxic compounds, and (2) production of adventitious roots on stems which may increase absorption of water. These adaptations appeared to be associated with greatly stimulated ethylene production in stems of flooded plants. The greater reduction of root growth over shoot growth in flooded seedlings will result in decreased drought tolerance after the flood waters recede. The generally low tolerance to flooding of seedlings of species that are widely rated as highly flood tolerant is emphasized.
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    A comparison of nine species of arbuscular mycorrhizal fungi on the development and nutrition of micropropagated Rubus idaeus L. cv. Glen Prosen (Red Raspberry) (2000)
    Springer
    Plant and soil 225 (2000), S. 53-61 
    Details
    ISSN: 1573-5036
    Keywords: AM fungi ; colonisation ; growth ; mineral nutrition ; red raspberry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Growth, development and nutrient status of micropropagated Rubus idaeus cv. Glen Prosen in response to inoculation with nine species of arbuscular mycorrhizal (AM) fungi from three different genera was investigated. The nine species of AM fungi included, Glomus clarum, G. etunicatum, G. intraradices, Gigaspora rosea, Gi. gigantea, Gi. margarita, Scutellospora calospora, S. heterogama and S. persica. Plant responses to AM fungi varied from growth enhancement to growth depression. Depressive growth effects were specific to Gigaspora species. Furthermore, particular species of AM fungi had unique effects on the mineral status of the raspberry plants. Importance of isolate selection for inoculation of micropropagated raspberry plants is discussed.
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    Deficiency of potassium but not phosphorus enhances root respiration (2000)
    Springer
    Plant growth regulation 32 (2000), S. 77-81 
    Details
    ISSN: 1573-5087
    Keywords: bioenergetics ; growth ; nutrition ; nutrient deficiency ; plant stress ; respiration ; root ; root:shoot ratio ; root respiration ; source-sink relationship ; stress ; stress physiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Root respiration of kohlrabi (Brassica oleraceavar. gongylodes) was measured non-destructivelyin vivo by infrared gas analysis of completeroot systems, using potted plants in sand culture andnutrient solutions, for six weeks under (a) nutrientsufficiency, (b) deficiency of all mineral nutrients,(c) potassium deficiency or (d) phosphorus deficiency.This was to study the adaptation to nutrient stress interms of changes in root growth, root respiration,assimilate allocation and energy requirement fornutrient uptake. Both deficiencies of phosphorus andpotassium increased the root:shoot-ratio. This wasattributed to the plants transferring a largerrelative proportion of assimilates to the roots thanto the shoots relative to nutrient-sufficient plants.Roots of nutrient-sufficient kohlrabi respired 1.7 or7.7 mg CO2 h−1 per g fresh or dry matter, respectively. However, potassiumdeficiency enhanced root respiration to 2.4 mgCO2 h−1 or 12.2 mg CO2 h−1 on a per g fresh or dry weight basis respectively. This originated from an additional2.6 mg glucose g−1 dry matter h−1 allocated to the roots and provided 50 Joule additional energy(150 versus 100 Joule g−1 dry matter h−1)which may become available for the proposedK+:H+ symporter for potassium uptake.
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    Feeding and growth of the pearl oyster Pinctada margaritifera (L.) in Dongonab Bay, Red Sea (1984)
    Springer
    Hydrobiologia 110 (1984), S. 241-245 
    Details
    ISSN: 1573-5117
    Keywords: Sudan ; pearl oyster ; feeding ; growth ; Red Sea ; Sudan
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Plankton samples and gut contents of P. margaritifera were analysed monthly from April 1972 to March 1973. Coscinodiscus sp. was the most ingested food by pearl oysters of all ages. However, food variety increased as the oyster grew older. Experiments confirmed the absence of food selectivity in P. margaritifera. Unlike the young ones, the adult showed reduced growth during summer (July–September), which coincides with its spawning season.
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    Survival and growth of early-instar nymphs of Ephemerella subvaria fed various diets (1984)
    Springer
    Hydrobiologia 119 (1984), S. 227-233 
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    ISSN: 1573-5117
    Keywords: Ephemerella subvaria ; autochthonous ; allochthonous ; algae ; diatoms ; macrophytes ; organic matter ; diet ; growth ; survival
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In two laboratory tests at 15 °C early-instar nymphs of the mayfly, Ephemerella subvaria were kept on different diets and their survival and growth recorded. The diets were either conditioned maple leaf discs; maple leaf disc remnants + Gammarus faecal material; maple leaf disc remnants + Hesperophylax faecal material; a clump of Cladophora strands or periphytic growth on small stones. A control group received no food. In both the tests, nymphs kept on Cladophora showed significantly (P ⩽ 0.05 or P ⩽ 0.01) higher percentage survival than for those on any other diet and the growth of these nymphs was second only to nymphs given periphyton as a diet. Although the nymphs on a diet of periphyton showed significantly (P ⩽ 0.01) higher growth as compared to those on other food sources, the survival percentage of these nymphs was the poorest, presumably because of food limitation. As expected, a diet of maple leaf discs resulted in significantly higher survival and growth of nymphs as compared to the nymphs not given any food. The results clearly demonstrated that autochthonous sources of organic matter can serve as excellent food for stream invertebrates.
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    Hydrostatic pressure and aquatic plant growth: a laboratory study (1984)
    Springer
    Hydrobiologia 111 (1984), S. 193-200 
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    ISSN: 1573-5117
    Keywords: aquatic pressure ; aquatic macrophyte ; growth ; depth distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A method was tested for growing aquatic vascular plants at elevated hydrostatic pressure so that the influence of other factors will not mask the specific plant-pressure interaction. Eighteen species of submersed vascular plants, belonging to twelve families and several distinct growth forms, were subjected to series of hydrostatic pressures including those well in excess of those encountered by the species when growing at its normal depths in lakes. Under no circumstances was the form of the plant altered even at the highest pressures, equivalent to that at a water depth of 23 m. The removal of confounding extraneous factors depends upon controlling competing algae, on raising the pressure in a series of steps, on maintaining the pressure without fluctuations during the growing period, on suiting the light and temperature conditions to the species and maintaining aquasoil air spaces or allowing them to develop. These preliminary data suggest that the level of hydrostatic pressure in the depth distribution of aquatic plants cannot be either a necessary or a sufficient controlling factor.
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    Life-history strategies and production of Tinodes waeneri (L.) (Trichoptera) in Lake Esrom, Denmark (1984)
    Springer
    Hydrobiologia 112 (1984), S. 93-104 
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    ISSN: 1573-5117
    Keywords: life cycles ; flight-periods ; growth ; production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The life cycle and production of Tinodes waeneri (L.) was examined at five shallow littoral localities in Lake Esrom, Denmark, during 1979/80. Five larval instars were demonstrated. The differences in temporal composition of instars indicated three different life cycles. A bivoltine strategy was shown for the most exposed locality which also had the highest average abundance equal to 11 500 ind. m−2. A univoltine population was found in the more sheltered NW part of the lake with an average density of 1 500 ind. m−2. At the three remaining stations the life cycles were partly bivoltine with wintering populations of mixed cohorts and densities between 10 500 and 3 000 ind. m−3. Two distinct flight periods with maxima in June and August were demonstrated for bi- and partly bivoltine populations. Differences in rates of growth and elimination added to the variability in life cycle. Growth rates peaked in August (5.0–7.4% d−1) at an average temperature of 20°C. Estimates of production ranged from 1.9 to 17.5 g AFDW m−2 a−1 with an average of 8.0 g AFDW m−2. The P/B ratios, which were within the expected range for uni- and bivoltine populations of trichopterans, were 5.73 for the bivoltine population and 3.31 for the univoltine population. Estimates of consumption revealed that the populations could be sustained by autochthonous epilithic production in the habitats. Variability in the quality and seasonal availability of food were judged to influence the type of life cycle.
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    Estimation des parametres de croissance (equation de Von Bertalanffy): application aux poissons tropicaux (1984)
    Springer
    Hydrobiologia 114 (1984), S. 13-15 
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    ISSN: 1573-5117
    Keywords: modeling ; growth ; tropical fishes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth parameters of the Von Bertalanffy equation have been computed by two methods for 24 populations of Tilapia in Malagasy lakes. The results obtained by the two technics are compared and the possible reasons of the observed differences are discussed.
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    Mass culture of brackish-water-adapted seaweeds in sewage-enriched seawater I. Productivity and nutrient accumulation (1984)
    Springer
    Hydrobiologia 116-117 (1984), S. 276-281 
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    ISSN: 1573-5117
    Keywords: seaweed ; Enteromorpha ; sewage treatment ; nutrient accumulation ; growth ; effect of salinity ; light and temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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    URL: http://dx.doi.org/10.1007/BF00027684
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    Measuring growth, production, and yield of the giant kelp, Macrocystis pyrifera (1984)
    Springer
    Hydrobiologia 116-117 (1984), S. 321-324 
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    ISSN: 1573-5117
    Keywords: seaweed ; Macrocystis pyrifera ; giant kelp ; yield ; productivity ; growth ; biomass
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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    URL: http://dx.doi.org/10.1007/BF00027695
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    Effects of diesel oil on recolonization of benthic algae (1984)
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    Hydrobiologia 116-117 (1984), S. 383-388 
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    ISSN: 1573-5117
    Keywords: seaweed ; benthic algae ; diesel oil ; growth ; recolonization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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    URL: http://dx.doi.org/10.1007/BF00027706
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    Respiration and plasma membrane ATPase in strawberry stolons (2000)
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    Plant growth regulation 30 (2000), S. 163-170 
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    ISSN: 1573-5087
    Keywords: ATPase ; bioenergetics ; Fragaria ananassa Duch ; growth ; ion transport ; photosynthesis ; proton transport ; respiration ; source-sink ; strawberry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The biochemical, physiological and anatomical properties of strawberry (Fragaria ananassa Duch.) cv. 'Cambridge Favourite' stolons were studied during growth. ATPase activity was measured, in microsomal and plasma membrane fractions, along with chlorophyll determination, in-situ photosynthesis measurements and scanning electron microscopy (SEM) and X-ray microanalysis of stolon cross-sections. Potassium-stimulated ATPase activity and proton-pumping, both together indicating the presence of plasma membrane ATPase, was greatest in the stolon tip, the tissue with the fastest growth and respiratory activity. The enzyme activity and respiration gradient from the tip of the stolon to the base was concomitant with xylem development which was more differentiated in the base than in the tip. These cross-sections also showed 30% greater amounts of calcium and potassium of the cryo-preserved basal part relative to the stolon tip. This gradient existed independent of the presence of daughter plants. A hypothesis is presented which suggests that for the long-distance longitudinal transport of nutrients this gradient between stolon tip and base is likely to be involved in stolon growth.
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    Effects of starvation on growth and reproductive apparatus of two immature freshwater snails Biomphalaria pfeifferi and Biomphalaria glabrata (Gastropoda: Planorbidae) (1984)
    Springer
    Hydrobiologia 109 (1984), S. 165-172 
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    ISSN: 1573-5117
    Keywords: Biomphalaria ; growth ; sexual maturity ; reproductive apparatus ; reproduction ; starvation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Starvation of immature snails of Biomphalaria pfeifferi and B. glabrata results in an arrest of growth and animals remain immature. Spermatogenesis is limited to spermatogonia (B.g.) or spermatocytes 1 (B.p.). The number and the size of oocytes remain inferior to that of controls. Animals show reduced genital tracts. Once feeding is restored, growth is resumed but wet weight and shell diameter do not reach the same level as in controls. Fecundity and gametogenesis do not differ from that in controls. Genital tracts weight is proportional to body weight.
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    The food and growth of pelagic 0+ Alestes nurse (Characidae) from the Blue Nile, near Khartoum (1984)
    Springer
    Hydrobiologia 110 (1984), S. 273-279 
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    ISSN: 1573-5117
    Keywords: Sudan ; Alestes ; growth ; feeding ; Nile
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The food, feeding habits and growth of 0+ Alestes nurse (Rüppel) from the Blue Nile near Khartoum, was investigated. 0+ A. nurse were observed to change their food from phytoplankton and small zooplankton during their pre-metamorphosis stages, to larger zooplankton (Daphnia spp., Chydorus sp.) and insects (larvae, pupae and imagines) during their post-metamorphosis stage. Their growth in length and weight was characterized by two distinct stanzas; during the first stanza, the fish increased in total length at a rate of 0.196 mm mm−1 wk−1, and in wet weight at a rate of 0.430 g g−1 wk−1. These rates were reduced during the second stanza to 0.046 mm mm−1 and 0.080 g g−1 wk−1, respectively. The calculated value of the exponent b in their length-weight relationship suggested that their growth was allometric.
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    Aspects of the biology of the catfish Clarias lazera (Cuv. & Val.) related to its economic cultivation (1984)
    Springer
    Hydrobiologia 110 (1984), S. 295-304 
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    ISSN: 1573-5117
    Keywords: Sudan ; Clarias ; breeding ; maturation ; hormones ; growth ; cultivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The seasonal abundance, population structure, reproduction, feeding, respiratory adaptations and tolerance were studied in the catfish Clarias lazera (Cuv. & Val.) in the reservoir of Jebel Aulia on the White Nile, and in the Green-Belt canals near Khartoum. Continuous monitoring of the ripe, spent and spawning females and immature fish in the population revealed that C. lazera breed synchronously in the autumn in the reservoir and rather sporadically in the canals. Medium-sized females were more fecund than old and young females. Administration of pituitary extract enhanced maturation, induced spawning in mature fish, stimulated body growth, especially in maturing specimens, and produced, as a side-effect, a diuretic response. Mature fish depended on pulmonary respiration for about 45% of the total oxygen requirement. C. lazera fed preferentially on its fry and on decayed proteinaceous food. The suitability of this species for economic cultivation is discussed.
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    Growth of Stylaria lacustris (L.) (Oligochaeta, Naididae) (1984)
    Springer
    Hydrobiologia 115 (1984), S. 105-107 
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    ISSN: 1573-5117
    Keywords: aquatic Oligochaeta ; Naididae ; growth ; experimental
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The peculiarities of the growth in weight and length of Stylaria lacustris (L.) on the basis of observations in experimental vessels are considered. The growth of this species fits a parabolic curve. The equations relating weight to absolute growth rate as well as weight to duration of life are given.
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    The biology of Psammoryctides barbatus (Grube) in English chalk streams (1984)
    Springer
    Hydrobiologia 115 (1984), S. 109-112 
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    ISSN: 1573-5117
    Keywords: aquatic Oligochaeta ; Psammoryctides barbatus ; growth ; cocoon production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The tubificid Psammoryctides barbatus is common in the sediments of English chalk streams. The species is primarily a spring and summer breeder with the most intense period of reproduction from April to June throughout its distribution in the river. Recruitment of juveniles takes place chiefly from June to August and most of the worms attain maturity in the following spring. In culture at 15 °C worms had attained 38 mm within 90 days of hatching and showed early signs of maturity. Growth rates and rates of cocoon production in culture are presented.
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    The effects of light on the growth and development of giant kelp (1984)
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    Hydrobiologia 116-117 (1984), S. 456-462 
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    ISSN: 1573-5117
    Keywords: seaweed ; kelp ; light ; growth ; biomass production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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    URL: http://dx.doi.org/10.1007/BF00027722
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    Morphological and physiological responses of Macrocystis pyrifera to nitrate enrichment (1984)
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    Hydrobiologia 116-117 (1984), S. 471-474 
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    ISSN: 1573-5117
    Keywords: seaweed ; Macrocystis ; Phaeophyta ; growth ; nutrients ; composition ; morphology ; mariculture
    Source: Springer Online Journal Archives 1860-2000
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    URL: http://dx.doi.org/10.1007/BF00027725
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    Preliminary study on the alginate contents of Sargassum spp. in Balibago, Calatagan, Philippines (1984)
    Springer
    Hydrobiologia 116-117 (1984), S. 547-550 
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    ISSN: 1573-5117
    Keywords: seaweed ; Sargassum ; alginate ; growth ; seasonality ; fertility ; yield
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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    URL: http://dx.doi.org/10.1007/BF00027743
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    The life-history, distribution, and production of Chironomus riparius and Glyptotendipes paripes in a prairie pond (1984)
    Springer
    Hydrobiologia 119 (1984), S. 65-72 
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    ISSN: 1573-5117
    Keywords: life-history ; production ; growth ; Chironomus riparius ; Glyptotendipes paripes ; Chironomidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract C. riparius and G. paripes exhibited univoltine life-cycles in Stephenson Pond; pupation, emergence and oviposition occurred mainly during May, and both species overwintered as mature fourth instar larvae. The marjority of larval growth for both species took place during the fourth instar stage (August–October), and growth and production were very low during late May to mid July when only young instars were present. Low production occurred during an interval when sestonic chlorophyll a concentration was very low, and the high production period corresponded to the Aphanizomenon bloom (August) and the autumn diatom pulse. None of the growth and production parameters investigated were correlated with temperature at the mud-water interface. Tube structure and behavior of the larvae indicate that G. paripes larvae are filter-feeders, whereas, C. riparius larvae are deposit-feeders.
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    Stable isotope evidence of benthic microalgae-based growth and secondary production in the suspension feeder Cerastoderma edule (Mollusca, Bivalvia) in the Marennes-Oléron Bay (2000)
    Springer
    Hydrobiologia 440 (2000), S. 317-329 
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    ISSN: 1573-5117
    Keywords: growth ; secondary production ; Cerastoderma edule ; stable isotope ratios ; microphytobenthos ; intertidal ; Marennes-Oléron Bay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The contribution of natural food sources to the growth and secondary production of the suspension feeding bivalve Cerastoderma edule (L.) was estimated under field conditions in the Marennes-Oléron Bay (Atlantic coast, France). Monthly estimates of abundance, biomass and cockle growth were combined with seasonal analyses of δ13C and δ15N ratios of juvenile and adult cockles, together with their potential food sources [i.e. suspended particulate organic matter (POM), microphytobenthos, macroalgae and seagrass] sampled at mid-tide level in a muddy sandflat. Adult cockles grew mainly in spring, whereas juveniles grew in summer and autumn, following spat recruitment in early summer. Total annual production and elimination of cockles were estimated to be 32.5 and 34.7 g AFDW m−2 yr−1. Relative contributions of each year class to production were ca 40, 41, 11 and 6% for 0-group, 1-, 3- and 4-yr-old cockles in 1995, respectively. Quantitative assessment of proportions of food sources to the annual secondary production of cockles was obtained by using a simple carbon isotope-mixing model with microphytobenthos (δ13C = −16.0±0.6‰) and POM (δ13C = −22.2±1.1‰) as end-members. On average, more than 70% of the total annual cockle production originated from microphytobenthos, with a much higher contribution for the 0-group (88%) than for adult cockles (60%). The between-age difference was induced mainly by changes in the availability of food resources (benthic versus planktonic) during the non-synchronous growing seasons of juvenile and adult cockles.
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    A control mechanism of the phytoplankton respiration in a eutrophic reservoir (1980)
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    Hydrobiologia 72 (1980), S. 125-129 
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    ISSN: 1573-5117
    Keywords: Phytoplankton ; respiration ; photosynthesis ; growth ; feedback mechanism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the eutrophic Bautzen reservoir (German Democratic Republic) the compensation light intensities (photosynthesis = respiration of the phytoplankton) have been found to be extremely low if no free carbon dioxide is available. This result is interpreted as a minimization of the cell respiration under CO2-limitation of the photosynthesis.
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    Interactions of feeding rates on growth, food conversion and body composition of the freshwater catfish Mystus vittatus (Bloch) (1981)
    Springer
    Hydrobiologia 78 (1981), S. 25-32 
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    ISSN: 1573-5117
    Keywords: catfish ; feeding rates ; growth ; body composition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Food intake, growth, conversion efficiency and body composition of the non-air breathing catfish Mystus vittatus (Bloch) were studied in relation to different feeding levels. Fish weighing 817.9 ± 104.00 mg was found to consume a maximum of 156.0 mg live Tubifex worm/g day-1. Geometrically derived feeding rates of 6.75, 23.00 and 26.00 mg dry food/g live fish day-1 represent the maintenance, optimum and maximum levels respectively. The SDA increased from 6.75 mg/g day-1 at maintenance to 13.50 mg/g day-1 at maximum feeding rate. Starvation brougt about increase in body water content, while there was concomitant decrease in fat and crude protein.
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    Hydrostatic pressure as the controlling factor in the depth distribution of Eurasian watermilfoil, Myriophyllum spicatum L. (1981)
    Springer
    Hydrobiologia 79 (1981), S. 239-244 
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    ISSN: 1573-5117
    Keywords: aquatic pressure ; depth distribution ; growth ; Myriophyllum ; Watermilfoil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract These experimental studies have shown that this plant will grow successfully at pressures encountered in water at depths as great as 17 m. When there were suitable levels of light, temperature, nutrients and aeration, the plants grown under constant hydrostatic pressure for three weeks showed variations in the measured amounts of new growth but no measure could be associated with the constant increased hydrostatic pressure. Sudden changes in pressure are thought to play a significant role in aquatic plant growth under experimental conditions.
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    Test of Competitive Interactions for Space Between Two Benthic Fish Species, Burbot Lota lota, and Stone Loach Barbatula barbatula (2000)
    Springer
    Environmental biology of fishes 58 (2000), S. 439-446 
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    ISSN: 1573-5133
    Keywords: competition ; substrate ; habitat preferences ; growth ; foraging efficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The substrate preferences, growth rates and foraging efficiency of two small benthic fish species, juvenile burbot, Lota lota, and stone loach, Barbatula barbatula, were compared in combined outdoor mesocosm and indoor laboratory experiments. Both species preferred the same stony substrate when alone, but significant differences in habitat selection were found between the two species under food deprivation and competition conditions. In burbot, preference for the stony habitat was reinforced under food-deprivation conditions and became even stronger when a potential competitor, the stone loach, was present. In contrast, stone loach switched to the gravel substrate when either starving or in the presence of a heterospecific competitor. Growth rates and foraging efficiency of burbot were significantly highest in the stony substrate and decreased with finer substrates. In stone loach, neither growth rates nor foraging efficiency were significantly different among the different substrates. The results provide an example of habitat partitioning by means of different competition styles, with a stenoecious, dominant style of the burbot and an euryoecious, evasive style of stone loach allowing coexistence of two sympatric fish species by graded interactions at an individual level in the littoral zone of a large lake.
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    Habitat selection in the larvae of two species of Zygoptera (Odonata): biotic interactions and abiotic limitation (2000)
    Springer
    Hydrobiologia 427 (2000), S. 167-176 
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    ISSN: 1573-5117
    Keywords: activity patterns ; foraging behaviour ; growth ; oxygen content ; predation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Field and laboratory experiments were set up to obtain data on the reasons for different habitat selection of Enallagma cyathigerum and Platycnemis pennipes. (1) Rearing of larvae in two different ponds showed that while P. pennipes was not able to survive conditions of low oxygen content, 50% of the E. cyathigerum larvae survived. (2) In field predation experiments with sticklebacks and dragonflies as predators, we found that E. cyathigerum suffered highest predation by the fish. In P. pennipes, mortality was highest with Anax imperator. (3) Experiments regarding larval behaviour showed that E. cyathigerum was generally more active and had higher foraging success than P. pennipes. Both species reduced activity in the presence of fish, but E. cyathigerum did so to a minor extent. In contrast to P. pennipes, E. cyathigerum showed escaping behaviour. (4) In the laboratory, the growth of E. cyathigerum was faster than that of P. pennipes.
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    Growth, mortality and reproduction of Sargochromis codringtonii in Lake Kariba, Zimbabwe (2000)
    Springer
    Hydrobiologia 438 (2000), S. 237-244 
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    ISSN: 1573-5117
    Keywords: Sargochromis codringtonii ; growth ; reproduction ; Lake Kariba
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Age determination of Sargochromis codringtonii was undertaken using scalimetry. Marginal scale analysis, used for age validation, indicated that annulus formation occurred in October and November. The possible reasons for this are discussed. S. codringtonii is relatively long-lived, surviving up to 8 years. It is sexually dimorphic with males growing at a faster rate and attaining a larger size than females. It is suggested that the mouth brooding habits of the female fish is one possible reason for sexual dimorphism. A higher total mortality rate (Z) was recorded for females as compared to males. S. codringtonii reproduces throughout the year, but with a peak during the hot wet months. The right ovary is atrophied and the possible significance of this is discussed.
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    URL: http://dx.doi.org/10.1023/A:1004135521127
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    Laboratory culture of Chironomus tentans for use in toxicity testing: optimum initial egg-stocking densities (2000)
    Springer
    Hydrobiologia 438 (2000), S. 251-256 
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    ISSN: 1573-5117
    Keywords: Chironomus tentans ; culture ; toxicity testing ; growth ; emergence ; density
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The midge Chironomus tentans Fabricius is a commonly used freshwater invertebrate in sediment toxicity tests. Rigorous laboratory culturing techniques are needed to provide organisms of uniform quality and known age for use in testing and for the continuation of the culture itself. This study was conducted to determine the effect of initial culture stocking density on: (1) post-hatch (larval) dry weight, body length and head-capsule width at 10 and 20 days; (2) time to emergence; (3) number and sex of emergent adults; (4) number of larvae and pupae at test termination (day 42 post hatch); and (5) adult dry weight. Three egg stocking densities were used 690 (1.1 eggs cm−2), 1043 (1.7 eggs cm−2) and 1463 (2.4 eggs cm−2). Mean weight of larvae at 10 days in high density tanks (0.13 mg/organism) was significantly higher (P=0.003) than both the medium and low density tanks (0.10 and 0.09 mg/organism, respectively). No significant differences between the three stocking densities were observed for the body length or head-capsule width at either 10 or 20 days post-hatch. Although not statistically significant, larval dry weight decreased with increased stocking density at day 20. A significantly (P=0.02) greater number of females (173±28) emerged from the low stocking density compared to both the medium and high stocking densities (123±45 and 118±54, respectively). Peak adult emergence for the low and medium stocking densities occurred between days 22 and 25 post-hatch, whereas peak adult emergence occurred between days 30 and 33 for the high stocking density. Survival relative to the initial number of eggs stocked was significantly greater (P=0.007) in the low density treatment compared to that in either the medium or the high density treatments. Mean adult weight exhibited an inverse relationship with initial stocking densities. At test end, there was not a significant difference in the mean number of organisms surviving and emerging in the three density levels. The central tendency for number of organisms surviving for all three treatments was 504 organisms per tank (0.82 organisms cm−2). The results of this experiment suggest that an optimal egg stocking density of 1.0 egg cm−2 (∼600 eggs/tank) be used with the feeding rate identified. This would ensure uniform larvae at the appropriate developmental stage (2nd–3rd instar) needed for toxicological research/testing (e.g. 10 days post-hatch), as well as producing sufficient emergence of males and females for future culture establishment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004187505198
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  • 93
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    Effects of eyestalk ablation on growth and food conversion efficiency of the freshwater prawn Macrobrachium lanchesteri (de Man) (1981)
    Springer
    Hydrobiologia 77 (1981), S. 77-80 
    Details
    ISSN: 1573-5117
    Keywords: Macrobrachium ; eyestalk ablation ; growth ; Conversion of food
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Bilateral eyestalk ablation in the freshwater prawn Macrobrachium lanchesteri results in high mortality, while unilateral eyestalk ablated prawns exhibited a high survival rate. There was marked increase in the growth of bilateral eyestalk-ablated prawns (47.70 mg/prawn) as compared to those that were unilaterally ablated (19.19 mg/prawn).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00006391
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  • 94
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    Growth and mineral nutrition of two Chlorococcalean algae (1981)
    Springer
    Hydrobiologia 79 (1981), S. 15-20 
    Details
    ISSN: 1573-5117
    Keywords: mineral nutrition ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of composition of the medium and pH on the growth of Pediastrum duplex Meyen and Dictyosphaerium pulchellum Wood was studied. Both species showed preference to alkaline conditions. The ammonium nitrate grown colonies of D. pulchellum lacked mucilage and showed a more compact form, resembling D. pulchellum var. minitum Deflandre. From this it appears that D. pulchellum var. minitum is a nutritional variant of the species and not a stable variety.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00005816
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  • 95
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    Cannibalistic phenomena in salamandra salamandra larvae in certain water bodies and under experimental conditions (1980)
    Springer
    Hydrobiologia 75 (1980), S. 123-128 
    Details
    ISSN: 1573-5117
    Keywords: Salamandra ; Urodela ; metamorphosis ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Salamandra salamandra larvae originating from a single batch (layed by one female) were raised at different temperatures and on ion-rich or distilled water. Temperature, but not the presence or absence of ions affected growth. Larvae originating from one batch or from several batches born on the same day, were kept without food for long periods of several months in order to observe cannibalistic predation under such conditions. This phenomenon is known in natural populations of salamanders inhabitating either rain pools in rocks or permanent springs poor in aquatic life. It was found that cannibalism increased under experimental conditions proportionally to the increase in size between the larvae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00007425
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  • 96
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    Growth, condition and gonad development of bream (Abramis brama L.) in relation to its feeding conditions in Tjeukemeer (1982)
    Springer
    Hydrobiologia 95 (1982), S. 311-320 
    Details
    ISSN: 1573-5117
    Keywords: bream ; growth ; condition ; fecundity ; zooplankton ; chironomids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The bream (Abramis brama L.) population of Tjeukemeer was studied for three successive years. The growth, condition, gonad development, diet and feeding conditions of the fish are described. Food competition for two years with the then abundant young planktivorous smelt (Osmerus eperlanus) and perch (Perca fluviatilis) resulted in a decreased growth rate, condition and gonad development of the larger bream. The biomass of chironomids was too small in relation to that of the zooplankton to be important for the bream population, although they were eaten more efficiently.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00044492
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  • 97
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    Biology of the Sand Smelt, Atherina presbyter (Teleostei: Atherinidae), Off the Canary Islands (central-east Atlantic) (2000)
    Springer
    Environmental biology of fishes 59 (2000), S. 91-97 
    Details
    ISSN: 1573-5133
    Keywords: age ; growth ; reproduction ; mortality ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Atherina presbyter is a common fish off the Canary Islands. Age, growth, reproduction, and mortality of the species are studied based on sampling carried out from July 1995 to June 1996. The parameters of the total length–total weight relationship are: a=0.004521, and b=3.0771. Otoliths age readings indicate that the sampled population consists of four age groups (0–III years). The von Bertalanffy growth parameters for all individuals are: L∞=122 mm total length, k=0.79 year−1, and t0=−0.21 years. Individuals grow quickly in their immature first year, attaining approximately 60% of their maximum length. After the first year, the annual growth rate drops rapidly, because the energy is probably diverted to reproduction. It is a gonochoristic species with no evidence of sexual dimorphism. The gonad is present as a single diffuse testis in males and as a single discrete ovary in females. The overall ratio of males to females is not significantly different from 1:1. The reproductive period of the species is protacted (February to June). The peak of the reproductive effort occurs in April–May. The size at first maturity is 68 mm. The population is being heavily exploited.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007643732673
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  • 98
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    Effects of Group Membership and Size Distribution within a Group on Growth Rates of Juvenile Sablefish Anoplopoma fimbria (2000)
    Springer
    Environmental biology of fishes 59 (2000), S. 199-209 
    Details
    ISSN: 1573-5133
    Keywords: fish behavior ; schooling ; size disparity ; density ; growth ; food availability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Group membership can confer both advantages and disadvantages to growth in juvenile fishes. The balance between costs and benefits of social interactions can shift depending on such factors as the composition of the group (density and size disparity) and the availability of food. We examined the effect of these factors on absolute growth and growth depensation in juvenile sablefish, Anoplopoma fimbria. Increasing density and increasing size disparity had little influence on absolute growth rates of juvenile sablefish and the effects of these social factors were not modified by ration level. In experiments testing density effects, absolute growth did not differ among groups of 1, 3, or 10 fish held at high rations, but at low rations single fish exhibited a different pattern of size-dependent growth compared to fish in groups. In experiments testing disparity effects, absolute growth did not differ between groups with an even size distribution and groups with a mixed size distribution. The relative size of an individual within a group, i.e., small, medium, or large, also did not modify growth, despite evidence of higher chasing behavior in mixed size distributions. Although the growth of small fish was not diminished in the presence of large fish, negative impacts of size disparity were expressed in high levels of cannibalism, which occurred in 42% of groups with a mixed size distribution. Significant growth depensation over time occurred in the density experiment, but not in the size disparity experiment, possibly due to the shorter duration of the latter experiment. We suggest that growth depensation was generated by individual variability in growth capacity rather than social effects on growth rates. Schooling behavior, measured by group cohesion indices, increased with fish size and was higher in groups with an even vs. a mixed size distribution. These results for sablefish are consistent with other schooling species in which growth variability is determined by exploitative competition and/or genetic variability in growth capacity rather than interference competition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007659903444
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  • 99
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    Predator/prey interactions: A link between the individual level and both higher and lower level effects of toxicants in aquatic ecosystems (2000)
    Springer
    Journal of aquatic ecosystem stress and recovery 7 (2000), S. 145-153 
    Details
    ISSN: 1573-5141
    Keywords: behavior ; grass shrimp ; growth ; longevity ; mummichog ; neurotransmitter ; predator ; prey ; serotonin ; top-down
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Behavior can demonstrate linkages ofcontaminant effects at different levels oforganization from the biochemical/cellular to theorganism, population, and community levels.Mummichogs, Fundulus heteroclitus, from acontaminated area were previously found to havereduced condition, growth, and longevity, comparedwith conspecifics from clean sites. Thispopulation-level observation may be due to theirimpaired predator/prey behavior, which is associatedwith altered levels of serotonin in their brains. Theyare slow, less able to capture live food, and eat muchnon-nutritious detritus, which may contribute to theirdecreased growth and condition. They are also lessable to avoid being captured by blue crabs, which canalso contribute to their reduced life span andsize-structure. Grass shrimp, Palaemonetespugio, a major prey species, are not behaviorallyimpaired at this polluted site, but are more numerousand larger in size than at the reference site,probably due to reduced mummichog predation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009923414208
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  • 100
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    Effects of dietary carnitine and lipid on growth and body composition of hybrid striped bass (Morone chrysops ♀× M. saxatilis ♂) (2000)
    Springer
    Fish physiology and biochemistry 22 (2000), S. 297-302 
    Details
    ISSN: 1573-5168
    Keywords: Carnitine ; diet ; growth ; hybrid striped bass ; lipid ; Morone ; nutrition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A study was undertaken to investigate the effects of graded dietary levels and different types of carnitine on hybrid striped bass (Morone chrysops ♀ × M. saxatilis ♂ %) fed different levels of lipid. An incomplete factorial design was utilized in which diets containing lipid at either 5 or 10% were supplemented with l-carnitine at 0, 500, or 1000 mg kg−1 diet, dl-carnitine at 1000 mg kg−1 diet, or carnitine chloride to provide 1000 mg carnitine kg−1 diet. Juvenile hybrid striped bass (3.3 g fish−1) were stocked into individual 38-l aquaria connected as a brackish water (6‰), recirculating system and fed each diet in triplicate for 9 weeks. Supplementation of the diet with 1000 mg carnitine kg−1 increased muscle carnitine from 35.5 to 47.7 μg g−1 tissue. Carnitine supplementation did not result in increased weight gain regardless of carnitine level or type; however, weight gain showed a significant (p〈0.05) response to dietary lipid with fish fed diets containing 10% lipid growing 34% more than fish fed diets with 5% lipid. The hepatosomatic index also was unaffected by diet, but the intraperitoneal fat (IPF) ratio was significantly elevated (5.1 vs 3.2%) in fish fed diets with 10% lipid compared to those fed diets with 5% lipid. Fish fed diets containing 1000 mg carnitine kg−1 had increased IPF ratio values at 4.7% compared to 3.9% for fish fed the basal diet. Liver lipid also was responsive to dietary treatment, increasing from 6.7 to 8.8% of wet weight as dietary lipid increased from 5 to 10%. The relative quantities of triglycerides, free fatty acids and phospholipids in muscle and liver were not influenced by carnitine level, carnitine type or dietary lipid level. Supplementation of carnitine does not appear to be beneficial to hybrid striped bass based on either growth performance or body composition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007843223107
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