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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    European journal of nutrition 36 (1997), S. 299-302 
    ISSN: 1436-6215
    Keywords: Energy retention ; protein retention ; fat retention ; growth ; body composition ; broilers ; Energieansatz ; Proteinansatz ; Fettansatz ; Wachstum ; Körperzusammensetzung ; Broiler
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Mit steigender Aufnahme erhöht sich der Körperfettgehalt und der Körperproteingehalt nimmt ab. Es wird oft angenommen, daß jede Zunahme im Ansatz mit mehr Fett und weniger Protein verbunden ist. Experimentelle Ergebnisse widerlegen jedoch diese Annahme. In zwei Experimenten mit männlichen Broilerhühnern wurden die Tiere auf einem Niveau von 60 % und 100 % der empfohlenen Energieaufnahme gefüttert. Die Körperzusammensetzung bei 1500 g zeigte, wie erwartet, daß sich bei steigenden Aufnahmen der Körperfettgchalt vergrößert und der Körperproteingehalt abnimmt. Fettund Proteinansatz waren linear mit der totalen Energieretention (ER) korreliert. Das bedeutet, daß jede Zunahme im Ansatz den gleichen Protein- und Fettgehalt besitzt. Wenn der Fettansatz gleich Null ist wird nur Protein, etwa 50 % des maximalen Ansatzes, retiniert. Wenn ER=O ist, wird Protein angesetzt und Fett mobilisiert. Energie-und N-Bilanzuntersuchungen bestätigen die konstante Zusammensetzung jeder Vergrößerung des Ansatzes. Die Ergebnisse beider Experimente zeigen, daß die ER aus zwei Komponenten besteht: einem basalen konstanten täglichen Proteinansatz und einer variablen zusätzlichen ER, die hauptsächlich aus Fett besteht. Der basale Proteinansatz beträgt etwa 50 % des maximalen Ansatzes. Mit steigenden Energieaufnahmen wird der basale Proteinansatz mit einer zusätzlichen Menge von Protein und Fett im konstanten Verhältnis ergänzt.
    Notes: Summary With increasing intakes the body fat content increases and that of protein decreases. It is most often assumed that this is brought about because each increment in retention contains more fat and less protein. Experimental results, however, showed that this explanation is not true. In two experiments male broiler chickens were fed at levels between 60 and 100 % of recommended energy intake. Body composition at 1500 g showed, as expected, that with increasing intakes body fat content increased and protein content decreased. Both fat and protein retention per day were linearly related to total energy retention (ER). This means that each increment in retention has the same protein and fat content. At zero fat retention only protein was retained, about 50 % of maximal retention. At zero ER protein was retained and fat mobilized. Energy and N balance experiments confirmed the constant composition of each increment in retention. The results of both experiments show that total ER consisted of two components: a basic constant daily protein retention and a variable additional ER, mainly consisting of fat. The basic protein retention is about half of maximal retention. With increasing energy intakes the basic protein retention is combined with an additional amount of protein and fat in a constant ratio.
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  • 2
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    European journal of nutrition 36 (1997), S. 332-335 
    ISSN: 1436-6215
    Keywords: Nutrient intake ; protein metabolism ; protein synthesis ; growth ; energy expenditures ; Nährstoffaufnahme ; Proteinstoffwechsel ; Proteinsynthese ; Wachstum ; Energieaufwand
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Eine Zunahme von fettfreiem Gewebe tritt auf, wenn die Proteinsynthese größer ist als der Proteinabbau. Obwohl während des Wachstums von der Geburt bis zur Reife die absoluten Proteinsynthese- und -abbauraten ansteigen, nehmen dagegen die fraktionellen Raten ab. Bcide Prozesse reagieren auf die Nährstoffaufnahme. Es gibt aber deutliche Unterschiede zwischen den verschiedenen Geweben. Protein, Kohlenhydrate und Fett können den Proteinansatz bei unreifen Tieren und Kindern stimulieren. Die zugrundeliegenden Mechanismen und die Energieaufwendungen scheinen jedoch unterschiedlich zu sein.
    Notes: Summary Lean tissue growth occurs when the rate of protein synthesis exceeds the rate of protein breakdown. Althoughabsolute rates of protein synthesis and breakdown rise during growth from birth to maturityfractional rates fall. Both these processes are sensitive to nutrient intake but responses to feeding vary greatly amongst different tissues. Protein, carbohydrate and fat can all stimulate body protein accretion in immature animals and in children but the mechanisms by which they do so, and the energy expenditures involved, seem to be different.
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  • 3
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    Empirical economics 24 (1999), S. 23-44 
    ISSN: 1435-8921
    Keywords: Key words: Cointegration ; convergence ; growth ; Kalman filter ; JEL classifications: C22 ; O47 ; O57
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract. Augmented Dickey Fuller (ADF) and Kalman filter convergence tests are applied to annual GDPs per head to 16 industrialised countries from 1890 to 1989. Results favour convergence towards the US with a structural break following the Second World War. Estimates suggest that steady-states were higher after the war and that speeds of convergence are different across countries. The Kalman filter method dismissed the no convergence hypothesis more often than its ADF counterpart. This could explain the apparent contradiction in earlier empirical work on similar data sets (cross-section methods tended to favour convergence while time series methods were unable to dismiss the no convergence hypothesis.)
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  • 4
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    Entomologia experimentalis et applicata 80 (1996), S. 141-144 
    ISSN: 1570-7458
    Keywords: Polygonia c-album ; Nymphalidae ; host-plant selection ; growth ; size
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 5
    ISSN: 1570-7458
    Keywords: amylase inhibitor ; red kidney bean ; hard red winter wheat ; growth ; insects ; beetles ; plant resistance ; stored products ; protease inhibitor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Insect α-amylase inhibiting and/or growth inhibiting activities of proteinaceous inhibitors from red kidney bean (Phaseolus vulgaris) and hard red winter wheat (Triticum aestivum) were examined. The bean inhibitor was most effectivein vitro against α-amylases from the red flour beetle (Tribolium castaneum) and the confused flour beetle (T. confusum), followed by those from the rice weevil (Sitophilus oryzae) and yellow mealworm (Tenebrio molitor). The insect enzymes were from two- to 50-fold more susceptible than human salivary α-amylase. When the inhibitors were added at a 1% level to a wheat flour plus germ diet, the growth of red flour beetle larvae was slowed relative to that of the control group of larvae, with the bean inhibitor being more effective than the wheat inhibitor. Development of both the red flour beetle and flat grain beetle (Cryptolestes pusillus) was delayed by 1% bean inhibitor, but development of the sawtoothed grain beetle (Oryzaephilus surinamensis) and lesser grain borer (Rhyzopertha dominica) was not affected by either the bean or wheat inhibitor at the 1% level. Rice weevil adults fed a diet containing 1% bean or wheat inhibitor exhibited more mortality than weevils fed the control diet. When the wheat amylase inhibitor was combined with a cysteine protease inhibitor, E-64, and fed to red flour beetle larvae, a reduction in the growth rate and an increase in the time required for adult eclosion occurred relative to larvae fed either of the inhibitors separately. The bean inhibitor was just as effective alone as when it was combined with the protease inhibitor. These results demonstrate that plant inhibitors of insect digestive enzymes act as growth inhibitors of insects and possibly as plant defense proteins, and open the way to the use of the genes of these inhibitors for genetically improving the resistance of cereals to storage pests.
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  • 6
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    Entomologia experimentalis et applicata 79 (1996), S. 335-344 
    ISSN: 1570-7458
    Keywords: alkaloid ; developmental time ; early instars ; growth ; Manduca sexta ; molting duration ; phenolics ; plant-herbivore interactions ; thermal regime
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To understand the mechanisms underlying plant-insect herbivore interactions, it is necessary to examine the simultaneous effects of temperature, food quality and larval age. We examined the simultaneous effects of three allelochemicals (tomatine, rutin and chlorogenic acid) on the performance of first and second instar Manduca sexta larvae under two representative thermal regimes 21 : 10°C and 26 : 15°C for spring and summer, respectively. Thermal regime and allelochemicals interacted to influence the time from egg hatch to ecdysis to the third instar. On average, it took about half as much time to reach the third instar at 26 : 15°C as it did at 21 : 10°C. Separately, tomatine and rutin had a negative effect on developmental time from egg hatch to the third instar, but their simutaneous effects were not additive. Chlorogenic acid significantly reduced the negative effect of tomatine. The magnitude of the allelochemical effect was larger at the cooler thermal regime compared to the warmer regime. For instance, chlorogenic acid by itself had no effect at the 26 : 15°C regime, but at the 21 : 10°C regime it significantly shortened total developmental time. The effect of chlorogenic acid on stadium duration was distinctly different for the two instars. Chlorogenic acid shortened stadium duration of first instar larvae. However, depending on thermal regime and the presence of tomatine, chlorogenic acid had a negative, positive or neutral effect on stadium duration of second instar larvae. Molting duration of second instar larvae was shortened by a half day at the warmer thermal regime but was not affected by the allelochemicals. Final larval weight was influenced by rutin and chlorogenic acid. Caterpillars fed diets containing 20 μmoles of rutin were on average 10% lighter than those fed plain diet, whereas those fed diets containing 20 μmoles of chlorogenic adic were on average 7% heavier. However, the effect of chlorogenic acid depended on thermal regime. Overall, our results indicated that: 1) temperature and food quality can interact to influence insect performance and 2) these effects are influenced by larval age.
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  • 7
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    Entomologia experimentalis et applicata 80 (1996), S. 443-451 
    ISSN: 1570-7458
    Keywords: beta-carboline alkaloid ; Trichoplusia ni ; harmane ; harmaline ; amitriptyline ; imipramine ; monoamine oxidase inhibitor ; tricyclics ; growth ; feeding behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In this study we investigated the effects of two naturally occurring beta-carboline alkaloids and two synthetic tricyclic antidepressants on the growth and food consumption of fifth instar larvae of the cabbage looper, Trichoplusia ni Hübner (Lepidoptera: Noctuidae). In artificial diets at high concentrations (3,000 ppm), harmane, amitriptyline, and imipramine reduce growth and feeding; harmane reduced feeding consistently at a lower concentration (200 ppm). In animals other than insects, beta-carboline alkaloids inhibit monoamine oxidase (MAO) activity and thus affect rates of disposition of serotonin and other monoamine neurotransmitters. Because brain serotonin levels are associated with variation in rates of carbohydrate and protein intake in insects, the effects of beta-carboline alkaloid ingestion on dietary self-selection behavior were examined. Choosing between diets lacking carbohydrate but containing protein and diets lacking protein but containing carbohydrate, larvae consumed a greater proportion of diet containing protein but lacking carbohydrate in the presence of harmane than in its absence. These results are consistent with beta-carboline alkaloid-mediated persistence of serotonin in the brain due to MAO inhibition. Alternatively, these results could reflect alkaloid-mediated peripheral inhibition of sucrose taste receptors influencing ingestive behaviors. That beta-carboline alkaloid ingestion is associated with changes in feeding behavior is consistent with a possible defensive role for these compounds in plant foliage.
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  • 8
    ISSN: 1570-7458
    Keywords: insect endocrinology ; ecdysone ; juvenile hormone ; reproduction ; growth ; inhibin ; oostatin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The first insect folliculostatic peptide was isolated from vitellogenic ovaries of the mosquitoAedes aegypti. This decapeptide directly inhibits trypsin biosynthesis in the gut, and indirectly ovarian development. The factor was named Trypsin Modulating Oostatic Factor or TMOF by its discoverers. From the fleshfly Neobellieria bullata 2 folliculostatins have been isolated, the hexapeptide Neb-TMOF and the 19-mer Neb-colloostatin. The available data suggest that at least 2 of the 3 folliculostatins originate from matrix (like) proteins present in the ovary, a hitherto unknown source of hormones. Furthermore, one of the folliculostatins (Neb-TMOF) is a potent inhibitor of ecdysone biosynthesis by larval ring glands of fleshflies. The discovery of the dipteran folliculostatins, which do not show any resemblance to inhibins of vertebrates, may significantly contribute to a better understanding of the hormonal control of growth in insects and perhaps, in other animals as well. None of the 3 folliculostatins is blocked at its N- or C-terminus. This, in combination with the pleiotropy of their effects and the narrow species specificity make such peptides prime candidates for, testing their potential in insect pest control by means of molecular biological methods.
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  • 9
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    Entomologia experimentalis et applicata 53 (1989), S. 257-265 
    ISSN: 1570-7458
    Keywords: Antifeedant ; insecticide ; bisabolangelone ; analog ; feeding ; growth ; molting ; mortality ; sesquiterpenoid ; development ; phago-stimulant ; Pieris brassicae L. ; Lepidoptera ; Pieridae ; Angelica silvestris L. ; Umbelliferae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Bisabolangelone und drei Analoge wurden unter Laboratoriumsbedingungen auf ihre frasshemmende Wirkung in Raupen von Pieris brassicae L. (Lepidoptera: Pieridae) geprüft. Die Resultate von Zweifach-Wahlversuchen zeigten, dass sowohl die frasshemmende als auch die insektizide Wirkung von Bisabolangelone in den Analogen stark reduziert ist oder ganz verloren ging. Weitere Untersuchungen mit niedrigen Bisabolangelone-Dosen zeigten, dass das Fehlen von wohlschmeckender Nahrung zu einer drastischen Reduktion der Nahrungsaufnahme und des Wachstums der Raupen sowie zur Verhinderung der Häutung und zu hoher Mortalität führt. Deformationen, wie sie von bisabolangelone-behandelten Vorratsschädlingen gemeldet wurden, konnten bei P. brassicae nicht beobachtet werden.
    Notes: Abstract Bisabolangelone and three analogs were assayed, under laboratory conditions, for their antifeedant activity against Pieris brassicae L. (Lepidoptera: Pieridae) larvae. The results of dual-choice studies revealed that the potent antifeedant activity of bisabolangelone is greatly reduced or lost in the analogs. Insecticidal activity observed in the former was not detected either. Further studies using the lower rates of bisabolangelone showed that the absence of a preferable food resulted in a drastic reduction in feeding and growth, and produced high mortality and inhibition of molting. No developmental deformities reported in stored product insects treated with bisabolangelone were observed in P. brassicae during our studies.
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  • 10
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    Acta applicandae mathematicae 9 (1987), S. 219-237 
    ISSN: 1572-9036
    Keywords: 34A34 ; 34D99 ; 90A16 ; Nonlinear differential equations ; stability ; growth ; economic dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract This paper analyses the implications of persistent growth upon the stability properties of dynamic models. Besides the traditional concept of asymptotic stability, new stability criteria-strong/weak absolute, strong/weak relative, strong/weak logarithmic stability-are introduced, and global stability conditions for satisfying these criteria are stated for general first-order autonomous differential equations. The conflict between rapidity of growth and the degree of stability is demonstrated. Economic applications of the stability theorems are illustrated within the growth models of Harrod and Solow.
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  • 11
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    Cellular and molecular life sciences 41 (1985), S. 1621-1621 
    ISSN: 1420-9071
    Keywords: Chlorella ; cadmium ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Growth of 14 strains from fiveChlorella species is rather insensitive towards cadmium. One strain (211-1a) ofC. saccharophila, however, was found to have a sensitivity towards this toxic heavy metal about 100 times higher than that of the other strains ofC. saccharophila.
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  • 12
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    Cellular and molecular life sciences 42 (1986), S. 1170-1173 
    ISSN: 1420-9071
    Keywords: Lampreys ; Geotria australis ; ammocoetes ; larval life ; growth ; metamorphosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The average duration of larval life in the anadromous lamprey,Geotria australis (the sole representative of the Geotriidae) is estimated as 41/4 years. Compared with other lampreys, the ammocoetes ofG. australis have a slow growth rate, increase in length during the year preceding metamorphosis and typically enter metamorphosis at a small mean length (〈100 mm) and weight (〈1.2 g).
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  • 13
    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.
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  • 14
    ISSN: 1570-7458
    Keywords: Homoptera ; Aphididae ; Acyrthosiphon pisum ; Medicago sativa ; resistance ; amino acids ; sucrose ; phloem sap ; artificial diet ; ingestion ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Sur des milieux holidiques se différenciant par leur concentration en acides aminés ou en saccharose ou par leur spectre en acides aminés et copiant la sève de deux variétés de luzerne (sensible et résistante) nous avons étudié différents paramètres biologiques d'un biotype d'Acyrthosiphon pisum Harris afin de mieux comprendre les mécanismes de résistance à ce puceron. Que ce soit pour le reproduction et la survie des adultes ou pour la croissance et le développment larvaire, nous montrons l'influence spécifique de la concentration en saccharose et en acides aminés ainsi que celle du spectre en acides aminés des régimes artificiels. Ces différences de performances de A. pisum peuvent en partie être expliquées par les différences d'ingestion. Néanmoins pour des rapport saccharose/acides aminés identiques et pour des niveaux d'ingestion égaux, il existe selon les milieux de grandes différences de taux de reproduction et donc d'efficacités métaboliques. Les milieux copiant la sève de variétés sensible et résistante permettent jusqu'à présent d'expliquer une partie des observations faites sur végétal, mais démontrent que l'ignorance de certains facteurs phagostimulants présents dans la plante empêche une interprétation complète des effets observés.
    Notes: Abstract In order to understand the mechanisms of resistance of two lucerne cultivars (susceptible ‘Resistador’ and resistant ‘Lahontan’ clones) to a French biotype of Acyrthosiphon pisum Harris, several biological parameters of this aphid were investigated on sap-copied holidic diets differing either by their amino acid or sucrose concentrations or by the relative proportions of some amino acids. We recorded the quantitative influence of nutrient levels and amino acid profiles on adult survival and reproduction, as well as on larval growth and development. The differences in A. pisum performances on artificial diets may partly by explained by variable ingestion rates, but also by differences in metabolic efficiency of the ingested nutrients, which greatly depends on amino acid composition. Although holidic diet experiments partially confirm the biological assays of resistance on plants, they also point out a lack in our understanding of the factors present in the sap which are involved in phagostimulation in vivo, thus preventing a complete interpretation of observed resistance.
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  • 15
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    Entomologia experimentalis et applicata 35 (1984), S. 75-81 
    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.
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  • 16
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    Entomologia experimentalis et applicata 41 (1986), S. 121-133 
    ISSN: 1570-7458
    Keywords: Ips typographus ; bark beetle ; Scolytidae ; intra-specific larval competition ; growth ; simulation model ; breeding pattern
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Konkurrenz zwischen Larven des Borkenkäfers Ips typographus L. in Rundhölzern von Picea abies Karsten wurde im Laboratorium studiert. Um die Annahme zu testen, dass die Mortalität bei Borkenkäferlarven hauptsächlich von Futterkonkurrenz stammt, wurden die Parameter dieses Vorgangs geschätzt, die Zahl der Überlebenden vorausgesagt und verglichen mit der tatsächlichen Zahl Überlebender in jedem Rundholz. Die erforderlichen Voraussagen wurden mit dem Simulationsmodell von De Jong & Saarenmaa (1985) gemacht. In diesem Modell wird angenommen, dass die Larven Futter aufnehmen, in dem sie sich in der zweidimensionalen Rindenschicht bewegen und dass sie sterben oder sich vorzeitig in untergewichtige Käfer verwandeln, wenn sie in ein Gebiet gelangen, dessen Futter erschöpft ist. Es wurde geschlossen, dass der wichtigste Aspekt der Larvenbewegung im Hinblick aufs Überleben das gegenseitige Ausweichen ist. Die Muster der Larvengänge, wie sie aus einem Muttergang aufgrund gegenseitigen Ausweichens entstehen, wurden berechnet; sie stimmten sehr gut überein mit den beobachteten Mustern. Das Wachstum und das Überleben wurden in separaten Versuchen untersucht. Es wurde gezeigt, dass vorzeitiger Entwicklungsabschluss als Folge von Nahrungsknappheit eintritt. Das Überleben hängt davon ab, ob die Larve genug Futter zum Verpuppen erhalten hat. Dass die Larve eine bestimmte Grösse erreicht (Wachstum), war proportional zur Bewegung über eine bestimmte Distanz in der Rindenschicht. Unter den Versuchsbedingungen nahm das potentielle Trockengewicht der Puppen um 0,08 mg zu mit jedem mm Larvengang. Die minimale zur Verpuppung erforderliche Futtermenge war 20 mm Ganglänge, was proportional zu 1,6 mg Puppentrockengewicht ist. Aus diesen Resultaten wird geschlossen, dass Futterkonkurrenz die hauptsächliche Mortalitätsursache unter Larven von I. typographus in Rundhölzern im Laboratorium ist. Zudem wurde das Simulationsmodell erfolgreich überprüft; deshalb scheint es, dass Futterkonkurrenz entsprechend der vorigen Hypothese erfolgt. Die Annahme scheint vertretbar, dass dieser letzte Schluss auch für I. typographus unter natürlicheren Bedingungen zutrifft.
    Notes: Abstract A series of laboratory experiments were conducted to provide parameters for a simulation model for Ips typographus L. (Coleoptera, Scolytidae). This model illustrates larval competition and predicts brood survival in bolts. Brood survival depended upon larvae attaining a weight of at least 1.6 mg dry weight. The pattern of larval foraging in a bolt is hypothesized to be regulated by mutual avoidance among larvae. An analytical solution is presented for the construction of the pattern of larval paths originating from a single maternal gallery.
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  • 17
    ISSN: 1570-7458
    Keywords: Syrphidae ; Metasyrphus corollae ; cereal aphid ; Sitobion avenae ; quantification ; field populations ; biomass ; voracity ; growth ; development ; kill rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Le taux de mortalité de S. avenae provoqué par les larves de M. corollae a été mesuré au laboratoire pour évaluer l'impact de ce prédateur sur les populations de ce puceron dans la nature. L'évolution du poids des larves et de la biomasse de pucerons tués a été suivie tous les jours dans des conditions de température et humidité constantes. Un taux moyen de mortalité a été déterminé pour chaque stade larvaire du prédateur, il a servi à déduire les niveaux de mortalité quotidienne dans les champs.
    Notes: Abstract The rate of kill of cereal aphids by larvae of Metasyrphus corollae (F.) (Diptera: Syrphidae) was measured in the laboratory with the aim of assessing the impact of this predator on field populations of cereal aphids. Daily measurements were taken of changes in both the larval weight and the biomass of aphids killed by M. corollae in conditions of constant temperature and humidity. A mean relative kill rate was defined and calculated for each larval instar of the predator from which estimates of field daily rates of kill can be made.
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  • 18
    ISSN: 1570-7458
    Keywords: Coccinellidae ; Harmonia axyridis ; Semiadalia undecimnotata ; Aphids ; Acyrthosiphon pisum ; Pyralidae ; Anagasta kuehniella ; growth ; reproduction ; breeding ; natural prey ; unnatural prey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary Aphidophagous coccinellids Harmonia axyridis and Semiadalia undecimnotata were reared on eggs of the pyralid moth, Anagasta kuehniella during three generations previously killed by exposure to ultra violet radiation. Incidentally, these eggs are used for the mass production of Trichogramma. For H. axyridis larvae, this prey has the same nutritional value as the aphid Acyrthosiphon pisum (control). In adults, it causes an increase in reproductive activity which persisted during three generations. Decreased egg fertility is compensated for by stimulated oviposition. However, regardless of generations, the number of larvae produced per female per day remained equal to or became larger than the control. When the adults are transferred to aphid prey after 15 days of oviposition on the substitution food, a high level of fecundity is maintained and egg fertility improved, particulary during the last two generations. In S. undecimnotata, a specific aphid predator, preying on substitute prey is associated with prolonged pre-imaginal development and increased mortality, the latter affecting up to 50% of the larvae during the third generation. In adults, it induces a deterioration of the reproductive capacities (fecundity, fertility) which however seemed to improve during the third generation. Substitute prey has negative effect on these adults. At present, only H. axyridis might be considered for temporary mass production, as suggested by the results obtained at the end of the first generation.
    Notes: Résumé Les coccinelles aphidiphages Harmonia axyridis Pallas et Semiadalia undecimnotata Schneider (Coccinellidae) ont été élevées pendant trois générations à l'aide d'oeufs d'Anagasta kuehniella Zell. (Pyralidae) tués par une exposition à un rayonnement ultraviolet. Chez la première espèce, cette proie de substitution présente une valuer alimentaire comparable si ce n'est pas supérieure à celle du puceron Acyrthosiphon pisum (Harris). Ces résultats permettent d'envisager, dès à présent, une production massive dans ces conditions trophiques. La mise en place d'un élevage continu dépend de l'évolution sur un grand nombre de générations de certains paramètres biologiques notamment de la fertilité des femelles. Chez la seconde espèce, une telle application paraît impossible pour l'instant.
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  • 19
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    Entomologia experimentalis et applicata 29 (1981), S. 109-116 
    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.
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  • 20
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    Entomologia experimentalis et applicata 48 (1988), S. 225-232 
    ISSN: 1570-7458
    Keywords: Avena macrostachya ; Hordeum bogdani ; resistance ; Rhopalosiphum padi ; growth ; excretion ; amino acids ; leaf anatomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumè Lors d'examens systématiques antérieurs, Avena macrostachya (Bal. ex Coss. & Dur.) et Hordeum bogdani (Wil.) ont présenté une résistance élevée au puceron Rhopalosiphum padi (L.). Lorsqu'ils avaient un choix comprenant de l'avoine et de l'orge cultivés, les pucerons ailés ont atterri en nombres moins importants sur les espèces sauvages. Les résultats étaient cependant variables dans le complexe avoine. La production de nymphes et le poids des adultes étaient plus élevés sur espèces cultivées, ainsi que la durée du développement était plus longue sur les espèces sauvages. A partir du troisième stade, l'excrétion de miellat a été significativement plus faible sur les espèces résistantes. En général, le miellat y contenait moins de 1% d'acides aminés bien que sur H. vulgare il en contînt 3,5%. Les pourcentages d'acides aminés libres du miellat étaient semblables sur toutes les plantes (5,2–7,6%), à l'exception de H. vulgare sur lequel les pucerons excrétaient 22% des taux ingérés. Les acides aminés excrétés en fortes quantités sur les différentes plantes, comprenaient l'asparagine, l'acide γ-aminobutyrique, l'acide glutamique et la glycine. Des coupes de tissus n'ont révélé aucun obstacle mécanique clair à la pénétration des stylets. Les possibilités d'utiliser ces espèces sauvages comme source de résistance aux pucerons dans la sélection de l'avoine et de l'orge ont été examinées.
    Notes: Abstract In previous screening tests the two wild crop relatives Avena macrostachya (Bal., ex Coss. et Dur.) and Hordeum bogdani (Wil.) demonstrated a high degree of resistance to the aphid Rhopalosiphum padi (L.). In a choice situation using wild and cultivated oats and barley, alate aphids settled in lower numbers on the wild species. The results were, however, variable in the Avena combination. Nymph production was significantly higher, development time shorter and adult weight higher on the cultivated varieties. From the third instar and onwards the excretion of honeydew was significantly lower on the resistant plants. In general the honeydew contained less than 1% free amino acids although excreta from H. vulgare contained 3.5%. The percentage of free amino acids found in the honeydew was similar for all plant species (5.2–7.6%) except for H. vulgare, on which the aphids excreted 22% of the amounts ingested. Amino acids excreted in high proportions on all plants included asparagine, γ-aminobutyric acid, glutamic acid, and glycine. Tissue sectioning did not reveal any obvious mechanical barriers to stylet penetration. The potential use of these wild species as sources for aphid resistance breeding in oats and barley is considered.
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  • 21
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    European journal of nutrition 36 (1997), S. 205-213 
    ISSN: 1436-6215
    Keywords: Frying ; growth ; liver lipids ; lipaemia ; olive oil ; pregnancy ; rat ; Fritierung ; Wachstum ; Leberfett ; Olivenöl ; Schwangerschaft ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Um Informartionen über den Zusammenhang zwischen der Aufnahme von Fett, das zum Fritieren benutzt wurde, und dem Fetthaushalt während Perioden starken Körperaufbaus zu haben, wurde der Einfluß der Aufnahme von frischem Olivenöl (Gehalt polarer Verbindungen, 2 %; Ölsäure 78,9 mg/100 mg Öl, und Linolsäure 7 mg/100 mg Öl) und von Olivenöl, das 15 mal in Folge für das Fritieren von Kartoffeln benutzt worden war (Gehalt polarer Verbindungen 9 %; Ölsäure 75,8 mg/100mg Öl und Linolsäure 6,2 mg/100mg Öl) während der Gravidität, untersucht. Dazu wurden trächtige Wistar Ratten in zwei Gruppen geteilt, die beide eine isokalorische Diät bekamen, deren Fettanteil 15 % von frischem (unbenutztem) (P1) bzw. fritiertem (benutztem) (P2) Olivenöl stammte mit nicht trächtigen Ratten verglichen. Die Gravidität erhöhte (p〈0,01) die Futteraufnahme, das Körpergewicht, die Gewichtszunahmen und die Futterverwertung. Die Ölqualität beeinflußte dagegen diese Parameter nicht. Während der Gravidität stiegen die Serumwerte der Triglyceride (TG) (p〈0,01) und des Cholesterins (TC) (p〈0,05) an, während die der Phosphatide (PH) sanken (p〈0,01). Ein signifikanter Effekt der Ölqualität und eine Wechselwirkung zwischen Gravidität und Öl wurde für TG und PH festgestellt. Das Gewicht und der Fettgehalt der Leber der trächtigen Ratten stiegen signifikant an (p.〈0.05), Leber TC, TG und PH stiegen während der Gravidität (ungefähr um das 3-fache der Ausgangswerte), aber es traten keine signifikanten Unterschiede zwischen der Aufnahme von benutztem und nicht benutztem Öl (P2 vs P1) auf. Die Ergebnisse zeigen, daß die Aufnahme von leicht verdorbenem Olivenöl als alleinige Fettquelle der Nahrung keine besonderen Folgen für die Gravidität hat, was die Gewichtszunahme der Mütter und der Feten, die Lipämie und die Zusammensetzung des Leberfetts betrifft.
    Notes: Summary The effect of the consumption of unused olive oil (polar content, 2 %; oleic acid, 78.9 mg/100 mg oil, and linoleic acid 7 mg/100 mg oil) and olive oil used discontinuously for frying potatoes 15 times (polar content, 9 %; oleic acid, 75.8 mg/100 mg oil and linoleic acid 6.2 mg/100 mg oil) was studied in pregnant rats with the aim of better understanding the relationship between the consumption of fat used in frying and lipid metabolism during periods of intense anabolism. Trials were performed in pregnant Wistar rats, divided into 2 groups and fed isocaloric diets in which the fat content (15 % wt/wt) consisted of unused olive oil (P1) or oil previously used for frying (P2), and the results were compared with those of nonpregnant rats fed unused olive oil (NP1) and olive oil used for frying (NP2). Pregnancy increased (p〈0.01) food intake, body weight, weight gain, and food efficiency ratio (P2 vs NP2 and P1 vs NP1, respectively), but the treatment of oil included in the diets did not alter these parameters. Gestation significantly increased the serum triglyceride (TG) (p〈0.01) and total cholesterol (TC) (p〈0.05) concentrations and diminished that of phospholipids (PH) (p〈0.01). A significant effect of the type of oil consumed and a pregnancy x oil interaction on Tg and PH levels was observed. The weight of the liver and its fat content increased significantly (p〈0.05) as a result of pregnancy. Liver TC, TG, and PH increased (approximately 3 times the original values) during gestation, but no significant differences due to the intake of used or unused oil (P2 vs P1) were observed. The results indicate that the consumption of moderately altered olive oil, as the sole source of fat, does not alter the effect of pregnancy on the mothers' weight gain, lipaemia, and hepatic fat composition to any important degree.
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  • 22
    ISSN: 1436-6215
    Keywords: Body composition ; fat ; growth ; somatotropin ; pig ; Körperzusammensetzung ; Fett ; Wachstum ; Somatotropin -Schwein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung An 78 männlichen Kastraten und weiblichen Schweinen der Kreuzung Pietrain x (Deutsches Edelschwein x Deutsche Landrasse) wurden Untersuchungen zum Einfluß einer porcinen Somatotropin (pST)-Behandlung während des Wachstums auf die chemische Körperzusammensetzung der Tiere, das Adipozyten-Wachstum und das Fettsäure-Profil des Rückenspecks untersucht. Die intramuskulären Injektionen (1 oder 3 mg pST) wurden täglich ab durchschnittlich 65 kg Lebendgewicht bis zum Schlachten verabreicht. Nach der pST-Behandlung wurden bei den Kastraten in allen untersuchten Merkmalen signifikante Unterschiede festgestellt, während sich bei den weiblichen Tieren nur leichte Reaktionen zeigten. Das pST verursachte eine Zunahme des Wasserund Proteingehaltes bei gleichzeitiger Reduzierung des Lipidgehaltes besonders in den fettreichen Körperteilen der Tiere. Im Rückenspeck war der Gehalt an ungesättigten Fettsäuren erhöht und der Fettzelldurchmesser erniedrigt.
    Notes: Summary Seventy eight growing-finishing pigs (male castrates and females) of the cross-breed Pietrain x (Large White x German Landrace) were used to investigate the effects of pST treatment on the chemical composition of the body, the growth of adipocytes, and the fatty acid profile of the backfat. Intramuscular injections (1 or 3 mg pST) were administered daily from an average weight of 65 kg up to slaughter. After pST treatment significant changes in all studied characteristics were observed in barrows, whereas the females exhibited very small responses. The pST caused an increase of water and protein contents and a simultaneous decrease of lipid content especially in body parts rich in fat. Furthermore, the proportion of unsaturated fatty acids increased and the fat cell diameter decreased in the backfat.
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  • 23
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    Journal of productivity analysis 8 (1997), S. 293-310 
    ISSN: 1573-0441
    Keywords: growth ; USagriculture ; externalities ; spill-overs ; public R and D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract Growth in U.S. agriculture is linked to the non-farm economy through domestic terms of trade and factor market adjustments. With almost stable input growth, the relatively large contributions from growth in Total Factor Productivity (TFP) are passed on to intermediate and final consumers in the form of declining real prices for primary farm products. The resulting net growth in the real value of farm output (GDP) is relatively low (0.25% per annum). The decomposition of TFP suggests that public agricultural stock of knowledge and infrastructure are “robustly” associated with TFP growth, while spill-overs from private agricultural and economy wide research and development (R and D) are positive but, relatively small.
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  • 24
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    Nutrient cycling in agroecosystems 16 (1988), S. 217-226 
    ISSN: 1573-0867
    Keywords: Potassium fertilization ; grain sorghum ; savanna soil ; yield ; growth ; varietal difference ; Nigeria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Field trials were conducted at Samaru over a three-year period (1980–82) to study the yield, growth and nutrient concentration of three grain sorghum varieties (L. 187, SK5912 and FFBL) in relation to potassium fertilization in a savanna soil. Potassium application rates were 0, 25, 50 and 75 kg K ha−1. Year × potassium interactions were not significant although there were significant variety × K interactions. The highest grain yields for var. L.187, SK5912 and FFBL occurred from the application of 25, 50 and 75 kg K ha−1 respectively. Straw yield was generally increased by K application, which also promoted tillering and hastened flowering in grain sorghum. Although grain weight per head, head number per m2, grain number and 1000-grain weight were unaffected by this nutrient, weight per head was reduced by 22.8 per cent. K application enhanced N concentration of sorghum plants but caused decline in P concentration. The highest K rate gave the highest K concentration in each of the three varieties at 7 weeks after planting. Optimum K requirement of grain sorghum would seem to be between 25 and 50 kg K ha−1.
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  • 25
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    Nutrient cycling in agroecosystems 11 (1987), S. 245-266 
    ISSN: 1573-0867
    Keywords: model ; growth ; root/shoot ratio ; nutrients ; light ; winter wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The mathematical analysis presented in this paper of plant growth is based on the assumption that the influence of deficiencies in the major root nutrients of water, N, P and K is to reduce the fraction of the plant mass devoted to photosynthesis by increasing the root fraction, thereby diminishing the rate of growth of the total plant. A reciprocal phenomenon occurs with deficiency of light. Using literature data on the influence of environmental conditions on plant growth and in particular on the root/shoot ratio, the relevant rate expressions are derived in a simple form and appear to be generally similar for a wide range of plants during their vegetative phase of growth.
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  • 26
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    Nutrient cycling in agroecosystems 11 (1987), S. 267-281 
    ISSN: 1573-0867
    Keywords: model ; growth ; root ; soil exploration ; grain fill ; winter wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In the first part of this paper a model is derived for the exploration of the soil by roots in a growing crop with particular reference to cereals. The distribution of root density with depth is related to the growth of the above-ground parts and to the varying demand these place on the roots modified by the changing texture and nutrient status of the soil with depth. In the second part of the paper the growth of cereal seeds is modelled by being related to the photosynthetic capacity of the plant and the duration of its life following anthesis. The death of the plant is considered to be a consequence of the parasitic action of the seeds.
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  • 27
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    Nutrient cycling in agroecosystems 1 (1980), S. 177-190 
    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.
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  • 28
    ISSN: 1573-0867
    Keywords: Zea mays L. ; nitrogen fertilization ; plant density ; yield components ; growth ; micronutrient nutrition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Growth and yield components in field-grown maize (Zea mays L.) were enhanced by nitrogen fertilization ranging from 50 to 200 kg N ha−1. Ear diameter, kernel depth, grain: stover ratio, number of ears plant−1, plant height and dry matter production increased as N fertilization rate was increased up to 100 or 150 kg N ha−1. Tasselling in maize was hastened by N fertilization. Increasing plant density from 25000 to 75000 plants ha−1 increased plant height, dry matter production and delayed tasseling but reduced ear diameter, kernel depth, grain: stover ratio and number of ears plant−1. Increased N supply and plant density had no influence on the concentrations of Mn, Zn, Cu, and Fe in ear leaf; except that Mn concentration increased as N fertilization rate was increased up to 150 kg N ha−1. Nitrogen × plant density interactions on the concentrations of the micronutrients in maize ear leaf were not significant.
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    Nutrient cycling in agroecosystems 3 (1982), S. 25-36 
    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.
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  • 30
    ISSN: 1573-0603
    Keywords: growth ; differentiation ; mammary epithelium ; collagen gel
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    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.
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  • 31
    ISSN: 1573-0832
    Keywords: mosquito pathogen ; growth ; sporulation ; temperature ; pH ; salinity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The New Zealand strain of Tolypocladium cylindrosporum was cultured on Sabouraud dextrose agar medium under varying regimes of growth conditions. The isolate exhibited good tolerances to temperature (4–35 °C), pH (3–10) and salinity (0–7% NaCl). Optimal vegetative growth and sporulation were recorded between a temperature range of 20–30° C, pH of 5–6 and a salinity level of 0–2% NaCl. The North American isolate of the fungus showed similar tolerances, while the European isolate was less tolerant.
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  • 32
    ISSN: 1572-977X
    Keywords: Avicennia alba ; growth ; internodal sequences ; mangrove age determination ; Rhizophora apiculata ; Sonneratia caseolaris ; Thailand
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The occurrence of periodic changes in the length of the internodes of the seedlings of SE Asian mangrove species (Rhizophora apiculata, Avicennia alba, and Sonneratia caseolaris) growing in the Pak Phanang estuary (Nakhon Si Thammarat, SE Thailand) was confirmed. The annual nature of these periodic changes was verified through comparisons with the observed average number of internodes produced by plants tagged for one year. The cycles in the sequence of internodal length of the seedlings had an average (± SE) period of 16.0 ± 0.78 internodes for Avicennia alba, 25.0 ± 1.2 internodes for Sonneratia caseolaris, and 8.29 ± 0.40 internodes for Rhizophora apiculata. These values are remarkably close to, and not significantly different (t‐test, P 〉 0.05) from the average (± SE) annual number of internodes of 17.6 ± 0.8 for Avicennia alba, 28.8 ± 2.1 for Sonneratia caseolaris, and 8.03 ± 0.36 for Rhizophora apiculata produced in a year by tagged plants. In addition, the average (± SE) growth of the tagged plants was 0.39 ± 0.018 cm day-1 for Avicennia alba, 0.24 ± 0.015 cm day-1 for Sonneratia caseolaris, and 0.091 ± 0.0036 cm day-1 for Rhizophora apiculata. These estimates were very close to those (0.45 ± 0.06 cm day-1 for Avicennia alba, 0.32 ± 0.01 cm day-1 for Sonneratia caseolaris, and 0.13 ± 0.005 cm day-1 for Rhizophora apiculata) derived as the product of the mean number of internodes produced per day, calculated from the inferred number of internodes produced per year, and the mean length of the internodes of the plants. These findings indicate that the use of regular, annual changes in the length of the internodes of mangrove seedlings can be used reliably to determine their age and to estimate their growth rate.
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  • 33
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    Cellular and molecular life sciences 41 (1985), S. 353-354 
    ISSN: 1420-9071
    Keywords: Teleost fish, freshwater ; muscle, white myotomal ; myotomal muscle ; muscle fibers ; fish size ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dynamics of increase of white myotomal muscle fibers of four species of freshwater teleosts (Salmo gairdneri, Pimephales notatus, Esox masquinongy andE. americanus vermiculatus) from three families (Salmonidae, Cyprinidae, Esocidae) representing a variety of maximum attainable sizes and growth rates, have been investigated. There are at least three major differences in these dynamics, and there appears to be an association between the ability of a fish species to attain large size (and grow fast) and its ability to recruit new fibers into this predominant tissue of the myotomal mass.
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  • 34
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    Cellular and molecular life sciences 44 (1988), S. 776-777 
    ISSN: 1420-9071
    Keywords: Fourier analysis ; growth ; selection ; size ; shape
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fourier analysis of videodigitised outlines of mouse vertebrae from two stocks, a pseudo-longitudinal series of mice aged 25–60 days and one selected for large or small body size over many generations shows that the shape changes due to normal growth are not similar to those produced by selection for body size.
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  • 35
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    Aquatic sciences 51 (1989), S. 296-305 
    ISSN: 1420-9055
    Keywords: Arctic char ; growth ; maturation ; reoligotrophication ; Lake Walenstadt
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Within one decade the yield in arctic char fishery of Lake Walenstadt (Switzerland) has dropped from 1.7 kg · ha−1 to 0.7 kg · ha−1. In the same period growth decreased by about 15%. The fish considered as “degenerated dwarfed chars” by fishermen are supposed to mature in very young ages. The change of the growth pattern can be related to reoligotrophication of the lake and impoverishments of the food source. Compared to other arctic char populations in Switzerland maturation takes place at least one year later.
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  • 36
    ISSN: 1420-9071
    Keywords: Serratia marcescens ; growth ; prodigiosin ; prodigiosin condensing enzyme ; secondary metabolites
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    Topics: Biology , Medicine
    Notes: Summary Prodigiosin condensing enzyme (PCE) activities were present inSerratia marcescens wild type 08, mutants OF, WF and 9-3-3. Their specific activities exhibited different maxima and at different times during the late log phase or the early stationary phase of cell growth. The levels of prodigiosin and its precursors also showed a significant increase at this period. The results support that prodigiosin and/or its precursors are secondary metabolites. The ubiquity of the PCE activity in mutants deficient in prodigiosin biosynthesis suggest that this particular enzyme may also be present in non-pigmented clinical isolates.
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  • 37
    ISSN: 1420-9071
    Keywords: Alternating high magnetic fields ; eddy current ; magnetic flux concentration ; Caenorhabditis elegans ; growth ; reproduction ; behavior
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    Topics: Biology , Medicine
    Notes: Abstract Here we describe a device for testing possible influences of high magnetic fields on biological processes, by which alternating-current magnetic stimuli as high as 1.7 T can be administered. Experiments with a simple multicellular organism, the nematodeCaenorhabditis elegans, revealed that intermittent exposure to the magnetic fields modestly inhibited the animal's reproduction as well as its post-embryonic development, and caused a marked but transient derangement in its locomotory behavior. Available evidence indicates that alternating high magnetic fields can elicit both chronic and acute biological effects, but that the effects may be well tolerated or compensated for by the living organism.
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  • 38
    ISSN: 1432-1939
    Keywords: Key words Agrostis canina ; CO2 vents ; photosynthesis ; lignification ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The aim of this study was to characterise growth and photosynthetic capacity in plants adapted to long-term contrasting atmospheric CO2 concentrations (C a). Seeds of Agrostis canina L. ssp. monteluccii were collected from a natural CO2 transect in central-western Italy and plants grown in controlled environment chambers at both ambient and elevated CO2 (350 and 700 μmol mol−1) in nutrient-rich soil. Seasonal mean C a at the source of the plant material ranged from 610 to 451 μmol CO2 mol−1, derived from C4 leaf stable carbon isotope discrimination (δ13C). Under chamber conditions, CO2 enrichment stimulated the growth of all populations. However, plants originating from elevated C a exhibited higher initial relative growth rates (RGRs) irrespective of chamber CO2 concentrations and a positive relationship was found between RGR and C a at the seed source. Seed weight was positively correlated with C a, but differences in seed weight were found to explain no more than 34% of the variation in RGRs at elevated CO2. Longer-term experiments (over 98 days) on two populations originating from the extremes of the transect (451 and 610 μmol CO2 mol−1) indicated that differences in growth between populations were maintained when plants were grown at both 350 and 700 μmol CO2 mol−1. Analysis of leaf material revealed an increase in the cell wall fraction (CWF) in plants grown at elevated CO2, with plants originating from high C a exhibiting constitutively lower levels but a variable response in terms of the degree of lignification. In vivo gas exchange measurements revealed no significant differences in light and CO2 saturated rates of photosynthesis and carboxylation efficiency between populations or with CO2 treatment. Moreover, SDS-PAGE/ LISA quantification of leaf ribulose bisphosphate carboxylase/oxygenase (Rubisco) showed no difference in Rubisco content between populations or CO2 treatments. These findings suggest that long-term adaptation to growth at elevated CO2 may be associated with a potential for increased growth, but this does not appear to be linked with differences in the intrinsic capacity for photosynthesis.
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  • 39
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    Oecologia 71 (1987), S. 486-490 
    ISSN: 1432-1939
    Keywords: Helianthemum ; growth ; flowering ; age ; drought response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The hills of the Negev highlands, west of Sede Boqer, are typically covered by various half-shrub communities, including the deciduous species of Helianthemum vesicarium Boiss., an Irano-Turanian element that grows only on north facing slopes, and H. ventosum Boiss., a Saharo-Arabian element which grows on both slopes but mainly on those facing south. Upon irrigation, plants of H. vesicarium preserve their natural rhythm of activity during winter and remain deciduous throughout the summer. On the other hand, under a similar irrigation treatment, the growth and flowering season of H. ventosum is modified and is extended well into the summer. Thus, H. ventosum shows a high phenological plasticity, while H. vesicarium seems to be very conservative. The different response of the two species to an improved water regime may partly explain the differences in their natural habitats: H. vesicarium on the more humid north facing slopes and H. ventosum mostly on the more arid and extreme south facing ones. Plants of both species which grow near boulders attain larger sizes and denser stands than those on the slopes. Age analysis based on xylem ring counts of 859 plants of the two natural populations showed that the plants did not exceed 14 years and most of them reached the age of some 5 years only. In general more seedlings are established during rainy year-clusters than during dry ones. However, no direct correlation between seedling establishment and the annual rainfall of specific years could be found. The rapid turnover of plants in the stands of both species of Helianthemum resembles the behavior of desert annuals rather than that of most desert shrubs.
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  • 40
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    Journal of population economics 9 (1996), S. 415-428 
    ISSN: 1432-1475
    Keywords: H42 ; J 13 ; O 11 ; Fertility ; growth ; public education and health
    Source: Springer Online Journal Archives 1860-2000
    Topics: Sociology , Economics
    Notes: Abstract This paper considers the implications of the financing of government services to children when fertility decisions are endogenously determined. In particular, it is shown that when the services are financed by taxation, the equilibrium outcome is biased away from the socially preferred result. The bias results in higher fertility rates and lower economic growth rates than the efficient social optimum. This arises because each household internalizes the benefits, but not the costs of the tax-financed services. We consider alternative methods of financing the public provision of services and find that a combination of taxation and vouchers can eliminate the bias in the equilibrium outcome.
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  • 41
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    Journal of population economics 11 (1998), S. 273-291 
    ISSN: 1432-1475
    Keywords: JEL classification: F22 ; O3 ; J61 ; Key words: Immigration ; assimilation ; growth ; diversity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Sociology , Economics
    Notes: Abstract. This paper analyzes the welfare effects of immigration and its subsequent effect on ethnic diversity in a model featuring human capital spillovers which depend on the degree of ethnic heterogeneity, variation rates of time preference across individuals and endogenous levels of immigration and assimilation. In the model, an increase in ethnic diversity reduces the spillovers effect for the majority. Nonetheless, immigration can be welfare improving for the majority ethnic group even if it increases the degree of diversity as long as it raises the average human capital level and/or growth rate by increasing the proportion of people with low rates of time preference. However, if an economy is too homogenous, it will not be able to attract immigrants. Finally, if the level of immigration is not too high, then immigration also raises the net benefits to assimilation which leads to a more homogenous economy.
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  • 42
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    Journal of population economics 11 (1998), S. 517-534 
    ISSN: 1432-1475
    Keywords: Key words: Fertility ; mortality ; growth ; JEL classification: J13 ; O41
    Source: Springer Online Journal Archives 1860-2000
    Topics: Sociology , Economics
    Notes: Abstract. Economic and demographic outcomes are determined jointly in a choice-theoretic model of fertility, mortality and capital accumulation. There is an endogenous population of reproductive agents who belong to dynastic families of overlapping generations connected through altruism. In addition to choosing savings and births, parents may reduce (infant) deaths by incurring expenditures on health-care which is also provided by the government. A generalised production technology accounts for long-run endogenous growth with short-run transitional dynamics. The analysis yields testable time series and cross-section implications which accord with the empirical evidence on the relationship between demography and development.
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  • 43
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    Journal of population economics 9 (1996), S. 415-428 
    ISSN: 1432-1475
    Keywords: Key words: Fertility ; growth ; public education and health
    Source: Springer Online Journal Archives 1860-2000
    Topics: Sociology , Economics
    Notes: Abstract. This paper considers the implications of the financing of government services to children when fertility decisions are endogenously determined. In particular, it is shown that when the services are financed by taxation, the equilibrium outcome is biased away from the socially preferred result. The bias results in higher fertility rates and lower economic growth rates than the efficient social optimum. This arises because each household internalizes the benefits, but not the costs of the tax-financed services. We consider alternative methods of financing the public provision of services and find that a combination of taxation and vouchers can eliminate the bias in the equilibrium outcome. JEL classification: H42, J13, O11
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  • 44
    ISSN: 1432-072X
    Keywords: Key words Protein phosphorylation ; ATP-Pi exchange ; Light-harvesting complexes ; Reaction center ; Photosynthesis ; Photomorphogenesis ; Membrane ; growth ; Polypeptide insertion ; Phospho-amino esters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Membranes of Rhodobacter capsulatus strain U43 (pTX35) showed qualitatively very similar phosphorylation patterns under in vitro and in vivo conditions. In vitro, it was irrelevant whether the phosphate source was orthophosphate or ATP. Inhibitors of electron transport did not inhibit light-harvesting complex I (LHIα) (B870) polypeptide phosphorylation, except for o-phenanthroline, which was strongly inhibitory. Redox conditions regulated the amount of protein phosphorylated; external redox potentials between +200 and +300 mV promoted the reaction. Phosphorylation was inhibited by uncouplers such as carbonyl cyanide m-chlorophenyl hydrazone and nigericin plus valinomycin plus potassium ions. Inhibitors of the H+-ATPase were also inhibitory when the phosphate source was [32P]Pi or [γ-32P]ATP. From these results, it was concluded that an operative reaction center, a coupled membrane, and external redox potentials higher than +200 mV are required for optimum LHIα phosphorylation. We also demonstrated that phosphorylation of LHIα polypeptide occurs before insertion into the membrane and that phosphate is preferentially incorporated into specific domains within the cytoplasmic membrane. Intracytoplasmic membranes, identified here as light membranes, were found to contain a dephosphorylated LHIα polypeptide.
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  • 45
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    Invertebrate neuroscience 1 (1995), S. 199-206 
    ISSN: 1439-1104
    Keywords: phospholipase C ; inositol phosphate ; invertebrate vision ; olfaction ; growth ; differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: abstract Phosphatidylinositol-specific phospholipase C (PLC) is a family of enzymes that occupy a pivotal role in one of the largest classes of cellular signaling pathways known. Mammalian PLC enzymes have been divided into four major classes and a variety of subclasses based on their structural characteristics and immunological differences. There have been five invertebrate PLC-encoding genes cloned thus far and these fall within three of the four major classes used in categorizing mammalian PLC. Four of these invertebrate genes have been cloned fromDrosophila melanogaster and one is fromArtemia, a brine shrimp. Structural characteristics of the invertebrate enzymes include the presence of highly conserved Box X and Box Y domains found in major types of mammalian PLC as well as novel features. Two of the invertebrate PLC genes encode multiple splice-variant subtypes which is a newly emerging level of diversity observed in mammalian enzymes. Studies of the invertebrate PLCs have contributed to the identification of the physiological functions of individual isozymes. These identified roles include cellular processes such as phototransduction, olfaction, cell growth and differentiation.
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  • 46
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    Journal of thermal analysis and calorimetry 52 (1998), S. 537-542 
    ISSN: 1572-8943
    Keywords: fractals ; growth ; nucleation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The author presents a model based on multi-step nucleation for the heterogeneous decompositions described by nucleation and growth phenomena, taking into account the fractal nature of the nuclei.
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  • 47
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    Aquaculture international 6 (1998), S. 1-17 
    ISSN: 1573-143X
    Keywords: Atlantic salmon (Salmo salar) ; Condition factor ; feeding regimes ; growth ; proximate composition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of different feeding methods on growth and slaughter traits of Atlantic salmon, Salmo salar, have been examined. Swimming activity associated with feeding was greatest amongst fish fed using automatic feeders, intermediate amongst those fed predetermined rations by hand, and least in groups of fish fed to satiation twice per day. Fish fed to satiation ate more and grew faster than did those provided with rations predicted to support high rates of growth, but the fish fed to satiation had higher feed:gain ratios than those given predetermined rations as two meals per day. The muscle tissues of the fish fed to satiation had higher lipid (%) and lower moisture (%) contents than did those of the fish fed the predetermined rations, but differences in muscle composition could be accounted for by differences in the size of the fish. Lipid was positively, and moisture negatively, correlated with fish size, whereas per cent protein and dress-out losses were little influenced by fish size and feeding regime. The fish fed to satiation were slightly heavier for a given length than those in the other groups. There was, however, no evidence that the largest fish had the highest condition factor, nor could condition factor be used to predict per cent lipid in the muscle tissue. Size variation increased in all groups of fish, and this was, in part, due to the cessation of growth of maturing individuals. Size variation was, however, most marked in the groups fed using automatic feeders, suggesting that interindividual competition for food was greatest amongst these fish.
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  • 48
    ISSN: 1573-143X
    Keywords: bighead carp (Aristichthys nobilis) ; growth ; Laguna Lake ; salinity tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Bighead carp (Aristichthys nobilis Oshima) fry of various ages (11, 18, and 35 days post-hatch) were exposed to the low salinities encountered during the annual intrusion of seawater in Laguna Lake, Philippines. Practical indices of salinity tolerance assessed the effect of a 96 h direct exposure to low salinities (0–16‰). Mean (MST) and median survival times (MST50) of fry decreased as salinity of rearing medium increased. Younger fry were less able to tolerate exposure to these salinities than their older cohorts. Median lethal salinity after 96 h (MLS) revealed higher tolerance among 35–day old fry (7.6‰) than 11 (2.3‰) and 18–day old fry (6.0‰), demonstrating that survival in saline water depends on their age at initial exposure to low salinities. Mean body weight of 18–day old fry reared in 0 and 2‰ for 3 and 4 weeks was higher than for those reared in 4 and 6‰ for the same period. Growth over these periods was inversely related with the range of salinities tested. These results demonstrate that, despite their known stenohalinity, bighead carp fry possess some degree of osmoregulatory capability, allowing them to survive and grow in lakes subjected periodically to saltwater inflow.
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  • 49
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    Aquaculture international 7 (1999), S. 287-293 
    ISSN: 1573-143X
    Keywords: bone mineralization ; calcium requirement ; feed efficiency ; growth ; semi-purified diet ; tiger puffer (Takifugu rubripes)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Juvenile tiger puffer (Takifugu rubripes) were fed semi-purified diets with graded levels (0–0.40%) of calcium (Ca) supplements for 8 weeks at a temperature of 23.0–25.5 °C. At the end of the feeding experiment, average final body weight increased with increasing dietary Ca levels. A diet without Ca supplement resulted in poor average final body weight and 0.05% dietary Ca supplement could not significantly improve the growth. However, supplemental Ca levels of 0.10–0.40% significantly increased growth. Dietary Ca supplements of 0.10% or more also improved the feed efficiency in tiger puffer. Ca and phosphorus contents of the bone were independent of dietary Ca supplements. However, 0.40% Ca in the diet decreased the zinc and manganese contents of bone. Results indicated that supplemental Ca levels of 0.10–0.20% in a semi-purified diet were required to maintain normal growth, feed utilization and bone mineralization of tiger puffer.
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  • 50
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    Molecular and cellular biochemistry 146 (1995), S. 63-69 
    ISSN: 1573-4919
    Keywords: rice bran oil ; growth ; plasma lipids ; fatty acids ; lipoproteins
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    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The effects of feeding two levels of rice bran oil (RBO) on the growth, lipid parameters, and fatty acid composition of the plasma and liver of rats (Wistar strain) were compared with those produced on animals which had been fed the same levels of peanut oil (PNO). The control animals were fed synthetic diets containing 5 and 20% peanut oil (PNO) and the experimental groups were fed similar diets, containing the same level of rice bran oil (RBO). There was no significant difference with respect to the organ weights between the control and the experimental groups. In general, groups fed 20% oil gained more weight than groups fed 5% oil. The animals which received rice bran oil in their diet had, in general, comparatively lower levels of cholesterol, triglycerides and phospholipids. On the other hand, animals receiving 20% rice bran oil in their diet, showed an increase of 20% in high density lipoproteins (HDL-C), within 18 weeks (p〈0.05), when compared to the animals fed with peanut oil. Similarly, low density lipoprotein cholesterol (LDL-C) and very low density lipoprotein cholesterol (VLDL-C) were lower in RBO-fed groups, than in the PNO-fed groups. There was, however, no significant differences in the cholesterol/phospholipid (C/P) ratio of the two groups. Analysis of plasma and of liver fatty acids indicated, in a general way, the type of fat consumed. There were no significant difference in the P/S ratio, nor any in the oleic/linoleic, oleic/stearic, palmitoleic/palmitic, oleic/palmitic, and oleic/palmitoleic ratios. Furthermore, levels of saturated (SAFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids were identical in both the groups. Thus, our results suggest that feeding a high level of rice bran oil (RBO) has no deleterious effect on the growth and blood lipid profile of rats.
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  • 51
    ISSN: 1573-4919
    Keywords: NADH oxidase ; plasma membranes ; growth ; retinol ; retinoids ; HeLa cells
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    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Several retinoids, both natural and synthetic, were evaluated for their ability to modulate NADH oxidase activity of plasma membranes of cultured HeLa cells and the growth of HeLa cells in culture. Both NADH oxidase activity and the growth of cells were inhibited by the naturally-occurring retinoids all trans-retinoic acid (tretinoin) and retinol as well as by the synthetic retinoids, trans-acitretin, 13-cis-acitretin, etretinate and arotonoid ethylester (Ro 13-6298). For all retinoids tested, inhibition of NADH oxidase activity and inhibition of growth were correlated closely. With tretinoin, etretinate and arotonoid ethylester, NADH oxidase activity and cell growth were inhibited in parallel in proportion to the logarithm of retinoid concentration over the range of concentrations 10-8 to 10-5 M. Approximately 70% inhibition of both NADH oxidase activity and growth was reached at 10 µM. With retinol, trans-acitretin and 13-cis-acitretin, inhibition of NADH oxidase activity and growth also were correlated but maximum inhibition of both was about 40% at 10 µM. The possibility is suggested that inhibition of the plasma membrane NADH oxidase activity by retinoids may be related to their mechanism of inhibition of growth of HeLa cells in culture. (Mol Cell Biochem 166: 101-109, 1997)
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  • 52
    ISSN: 1573-4919
    Keywords: heart ; postnatal development ; sarcoplasmic reticulum ; phospholamban ; calcium transport ; spontaneously hypertensive rats ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract This comparative study investigates the relationship between sarcoplasmic reticulum (SR) calcium(Ca2+)-ATPase transport activity and phospholamban (PLB) phosphorylation in whole cardiac homogenates of spo`ntaneously hypertensive rats (SHR) and their parent, normotensive Wistar Kyoto (WKY) strain during early postnatal development at days 1, 3, 6, 12 and at day 40 to ascertain any difference in SR Ca2+ handling before the onset of hypertension. At day 1, the rate of homogenate oxalate-supported Ca2+ uptake was significantly higher in SHR than in WKY (0.25 ± 0.02 vs 0.12 ± 0.01 nmoles Ca2+/mg wet ventricular weight/min, respectively; p 〈 0.001). This interstrain difference disappeared with further developmental increase in SR Ca2+ transport. Western Blot analysis and a semiquantitative ELISA did not reveal any difference in the amount of immunoreactive PLB (per mg of total tissue protein) between strains at any of the ages studied. In addition, levels of phosphorylated PLB formed in vitro in the presence of radiolabelled ATP and catalytic (C) subunit of protein kinase A did not differ between SHR and WKY at days 1, 3, 6 and 12. At day 40, C subunit-catalyzed formation of 32P-PLB was reduced by 66% (p 〈 0.001) in SHR when compared to age-matched WKY In the early postnatal period between day 1 and 12 SR Ca2+-transport values were linearly related to the respective 32P-PLB levels of both SHR and WKY rats. The results indicate that cardiac SR of SHR can sequester Ca2+ at a much higher rate immediately after birth compared to WKY rats. The disappearance of this interstrain difference with further development suggests that some endogenous neuroendocrine or nutritional factor(s) from the hypertensive mother may exert an influence upon the developing heart in utero resulting in a transiently advanced maturation of the SR Ca2+ transport function in SHR pups at the time of birth.
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  • 53
    ISSN: 1573-4919
    Keywords: NADH oxidase ; protein disulfide-thiol interchange ; dipyridyl-dithio substrates ; plasma membrane ; auxin ; 2,4-dichlorophenoxyacetic acid ; growth ; plant (Glycine max)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Dipyridyl-dithio substrates were cleaved by isolated vesicles of plasma membranes prepared from etiolated hypocotyls of soybean. The cleavage was stimulated by auxins at physiological concentrations. The substrates utilized were principally 2,2′-dithiodippyrine (DTP) and 6,6′-dithiodinicotinic acid (DTNA). The DTP generated 2 moles of 2-pyridinethione whereas the 6,6′-dithiodinicotinic acid generated 2 moles of 6-nicotinylthionine. Both products absorbed at 340 nm. The auxin herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D) stimulated the activity approximately 2-fold to a maximum at about 10 μM. Concentrations of 2,4-D greater than 100 μM inhibited the activity. Indole-3-acetic acid stimulated the activity as well. The growth-inactive auxin, 2,3-dichlorophenoxyacetic acid (2,3-D), was without effect. DTNA cleavage correlated with oxidation of NADH and reduction of protein disulfide bonds reported earlier in terms of location at the external plasma membrane surface, absolute specific activity, pH dependence and auxin specificity. The dipyridyl-dithio substrates provide, for the first time, a direct measure of the disulfide-thiol interchange activity of the protein previously measured only indirectly as an auxin-dependent ability of isolated plasma membrane vesicles to restore activity to scrambled and inactive RNase.
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  • 54
    ISSN: 1573-4919
    Keywords: annexin V ; cardiac myocyte ; growth ; hypertrophy ; heart
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Recently it was shown that annexin V is the most prominent member of the annexin family in the adult heart [1]. Amongst others, annexin V has been suggested to play a role in developmental processes. The aim of the present study was to explore whether in the heart annexin V content and localization change during maturational and hypertrophic growth, in order to obtain indications that annexin V is involved in cardiac growth processes. First, in the intact rat heart annexin V content and localization were studied during perinatal development. It was clearly demonstrated that annexin V content in total heart transiently increased in the first week after birth, from 0.79 ± 0.06 µg/mg protein at l day before birth to a peak value of 1.24 ± 0.08 µg/mg protein 6 days after birth, whereafter annexin V protein levels declined to a value of 0.70 ± 0.06 µg/mg protein at 84 days after birth (p 〈 0.05). Differences in annexin V content were also observed between myocytes isolated from neonatal and adult hearts [0.81 ± 0.09 and 0.17 ± 0.08 µg/mg protein, respectively (p 〈 0.05)]. Moreover, during cardiac maturational growth the subcellular localization of annexin V might change from a cytoplasmic to a more prominent sarcolemmal localization. Second, in vivo hypertrophy induced by aortic coarctation resulted in a marked degree of hypertrophy (22% increase in ventricular weight), but was not associated with a change in annexin V localization or content. The quantitative results obtained with intact hypertrophic rat hearts are supported by findings in neonatal ventricular myocytes, in which hypertrophy was induced by phenylephrine (10-5 M). In the latter model no changes in annexin V content could be observed either. In conclusion, the marked alterations in annexin V content during the maturational growth in the heart suggest a possible involvement of this protein in this process. In contrast, the absence of changes in annexin V content and localization in hypertrophied hearts compared to age matched control hearts suggests that annexin V does not play a crucial role in the maintenance of the hypertrophic phenotype of the cardiac muscle cell. This notion is supported by observations in phenylephrine-induced hypertrophied neonatal cardiomyocytes.
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  • 55
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    Aquarium sciences and conservation 2 (1998), S. 9-19 
    ISSN: 1573-1448
    Keywords: Barbus tetrazona ; nutrition ; dietary requirement-phosphorus ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of increasing dietary concentrations of phosphorus on growth, feeding efficiency and body composition were studied in the tiger barb (Barbus tetrazona) (Bleeker, 1855). Juvenile tiger barbs (initial weight 0.33 ± 0.02 g) were fed purified diets containing graded levels of KH2PO4 to provide 0.17–1.57% available dietary phosphorus for 8 weeks in freshwater glass aquaria. The weight gain, feeding efficiency and mineral composition of the whole body and bone were significantly (p〈0.05) affected by dietary phosphorus. Growth response data calculated by broken line analysis showed that the minimum dietary phosphorus level required for maximum growth was 0.52%. The carcass protein, fat and ash contents but not moisture were affected by various dietary phosphorus levels. Fish fed a low-phosphorus diet had high body crude fat.
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  • 56
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    Journal of chemical ecology 12 (1986), S. 713-728 
    ISSN: 1573-1561
    Keywords: Alkaloids ; phenolics ; feeding trials ; digestibility ; growth ; Lespedeza cuneata ; Penstemon digitalis ; Microtus pennsylvanicus ; Microtus ochrogaster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Lespedeza cuneata contains high levels of phenolics and is a common food plant of the meadow vole (Microtus pennsylvanicus);Penstemon digitalis contains substantial quantities of alkaloids and is a common food plant of meadow voles and prairie voles (M. ochrogaster). We investigated the palatability of these plants and the effects of their secondary compounds on the digestion efficiencies and growth of both species of voles. Voles ate very little of either plant when alternative food was present. Phenolics and alkaloids were extracted from the plants, incorporated into separate artificial diets, and fed to weanling voles for three weeks.Lespedeza phenolics reduced the growth of meadow voles but not prairie voles throughout the feeding trial. These compounds disrupted digestion, reducing protein digestibility by more than half.Penstemon alkaloids lowered only the initial growth rates of prairie voles and had no significant effect on meadow voles. Prairie voles tended to increase food consumption rates on bothLespedeza andPenstemon diets. This response offset some of the decrease in digested protein intake in the first case, and offset the increased metabolic cost of processing the diet in the latter case. Our results indicate that althoughLespedeza phenolics andPenstemon alkaloids do influence consumption and digestibility of artificial diets, they do not greatly reduce the performance (i.e., growth or survival) of voles when consumed at levels generally observed for wild voles. However, these compounds probably do place an upper limit on the amount of freshLespedeza andPenstemon that can be consumed and contribute to the generalist feeding strategy of voles.
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  • 57
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    Journal of chemical ecology 13 (1987), S. 39-46 
    ISSN: 1573-1561
    Keywords: Solanum ; glycoalkaloid ; Leptinotarsa decemlineata ; protein ; growth ; Coleoptera ; Chrysomelidae ; α-tomatine ; α-solamarine ; β-solamarine ; α-solamine ; α-chacomine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Growth of larvae of the Colorado potato beetle,Leptinotarsa decemlineata (Say), as measured by weight gain, was determined when larvae were reared on synthetic diets containing measured quantities of protein and one of fiveSolanum glycoalkaloids. Data were analyzed to determine if growth was affected by these two aspects of phytochemical variation independently, or if there was a significant interaction component in larval weight gain to simultaneous variation in protein and glycoalkaloid concentration. For four of the five glycoalkaloids examined, a bivariate regression model without interaction accurately accounted for growth ofL. decemlineata larvae. For alpha-tomatine, however, a regression model with the addition of a (protein × glycoalkaloid) interaction term more accurately accounted for larval growth. The influence of this interaction was less than either protein or glycoalkaloid concentration alone. The variation in protein concentration accounted for most of the variation in larval growth, and high protein concentrations could more than offset the effect of high concentration of any of the five glycoalkaloids.
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  • 58
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    Journal of chemical ecology 25 (1999), S. 1455-1479 
    ISSN: 1573-1561
    Keywords: Turnera ulmifolia ; Euptoieta hegesia ; cyanogenesis ; Anolis sagrei ; tritrophic interactions ; host range ; sequestration ; growth ; development ; oviposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We examine the effects of the cyanogenesis polymorphism in Turnera ulmifolia on larvae, pupae, and adults of Euptoieta hegesia, the most damaging herbivore of T. ulmifolia in terms of tissue loss per unit time. We provide evidence that female E. hegesia do not show preference for host plants on the basis of their cyanogenesis level but do prefer T. ulmifolia over equally cyanogenic, closely related secondary host-plant species (Passiflora sp.). Similarly, cyanogenesis in T. ulmifolia has little effect on the food preference, growth, or development of the larvae. The potential host range of E. hegesia is limited, even within the genus Turnera, but this does not appear to be due to host-plant cyanogenesis. Pupae suffer very high mortality levels in the wild that are not associated with host-plant cyanogenesis, although our studies indicate that larvae are capable of sequestering cyanogenic glycosides from their host plants and possibly of synthesizing these or similar compounds. We provide evidence that the presence of sequestered cyanogenic compounds in the larvae protects them from terrestrial-based predators such as Anolis lizards
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  • 59
    ISSN: 1573-2932
    Keywords: Fish populations ; perch ; roach ; growth ; reproduction ; water chemistry ; acidification ; recover
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    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Acid-induced fish damage in small lakes in southern Finland was studied in a fish status survey of eighty lakes from 1985–1987. Later, twenty of these lakes were selected for further monitoring. A sampling of these lakes from 1988–1989 showed that the decrease in some perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) populations still continued. The results from the same lakes in 1992 showed that successful reproduction had taken place with many of the perch populations that had been close to extinction in 1985. In contrast, no signs of recovery in the roach populations were detected. The explanation for the appearance of new cohorts of perch could have been the decrease in acid deposition but the exceptional hydrological conditions of winters in the early 1990s may also have affected them. The different responses of the perch and roach populations were interpreted as a consequence of the different sensitivity of these two species to acidification. Even a slight improvement in the water quality has resulted in the appearance of strong new year-classes of perch, but not of roach. Therefore, more improvement in water quality is needed until a sensitive species like roach can reproduce again.
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  • 60
    ISSN: 1573-3297
    Keywords: genes ; environment ; development ; growth ; twins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Models of developmental continuity and change in quantitative phenotypes may be tested using longitudinal data from twins. We illustrate a procedure for establishing the power and required sample sizes for detecting developmental transmission against an alternative common-factor hypothesis. We explore the general effects of different heritabilities, different fidelities of environmental and genetic developmental transmission, and varying numbers of occasions of measurement. In addition, a constraint of wide application is postulated for the action of the environment; either environmental effects are transmitted (learned) and occasion specific or they exert a constant influence which is not transmitted (learned). While the situations we examine are necessarily restricted here, our explorations of power show that, providing that we measure on at least four occasions, it is easy to detect developmental transmission with workable sample sizes.
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  • 61
    ISSN: 1573-3297
    Keywords: anorexia ; maturity ; feed intake ; growth ; chickens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Long-term selection for low juvenile body weight has resulted in a line of chickens where sexual maturity is retarded or prevented because of anorexia.Ad libitum-fed pullets which had not commenced egg production by 240 days of age were randomly assigned to be force-fed or fedad libitum. Increasing food intake via force-feeding caused a significantly greater proportion of females to commence egg production than was noted forad libitum-fed controls. Moreover, of those pullets that commenced lay, age at onset was significantly earlier in those force-fed than in those fedad libitum.
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  • 62
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    Water, air & soil pollution 85 (1995), S. 1461-1466 
    ISSN: 1573-2932
    Keywords: ozone ; wheat ; Triticum aestivum ; growth ; senescence ; biomass partitioning ; photosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract In closed-chamber fumigation experiments dry matter partitioning and chlorophyll fluorescence of wheat were studied, analysing the effects of ozone during different stages of plant development. Ozone causes enhanced leaf senescence, leading to a loss of green leaf area and, consequently to a decreased supply of assimilates, affecting (in increasing order of severeness) stem, ear and grain productivity because of reduced storage pools for translocation. Leaves of plants before shooting stage were most sensitive but the lack of green leaf area after ear emergence had the most pronounced effects on grain yield. Measurements of photochemical capacity showed that evidence for negative ozone effects could be found in changes of chlorophyll fluorescence parameters in leaf sections not yet showing visible ozone injury. Negative effects on photosynthesis were more distinct with increasing accumulated ozone dose, with increasing age of leaf tissue and with increasing ozone sensitivity of the cultivar. The changes in chlorophyll fluorescence are most likely to be explained by a decreased pool size of plastoquinones caused by ozone.
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  • 63
    ISSN: 1573-3017
    Keywords: Tubifex tubifex ; sediment bioassay ; hormesis ; growth ; reproduction ; egestion rates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Toxicity assessment based on sediment chronic bioassays with the aquatic worm Tubifex tubifex was performed at ten contaminated sites in the industrial area of Bilbao (Northern Spain). One control and three reference sites were also included. Tubifex bioassay measures both survival and reproduction impairment. These endpoints have been contrasted and discussed in relation to somatic growth and both individual and total biomass of cocoons. Survival was only affected at one site which was heavily contaminated by organic compounds, mainly PAHs. A group of four severely ecotoxic sediments was characterised by a drastic reduction in number and size of cocoons, and adult somatic growth. In other group of sediments, some significant increases were found for these variables. It is suggested that these increases represent an effect of hormesis. An index of reproductive effort was used to integrate the relationship between somatic growth and reproduction. Values of reproductive effort at the test sediments were lower than those at the control sediment, suggesting a conservative strategy of oligochaete worms which consisted in an investment into somatic line (growth) at the expenses of offspring. Rates of food consumption which were estimated from egestion rates, were low at the contaminated sites. This fact could be related to the low production levels found at these sites and may reflect avoidance feeding behaviour of the oligochaete worms within the sediments. At some reference sites, high production could have resulted from high nutritional quality of sediments, or to an hormetic effect due to low concentration of some chemicals. Results are discussed in relation to toxicity data from sediment three-brood bioassay with Daphnia magna Straus performed separately on the same sediments.
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  • 64
    ISSN: 1573-4935
    Keywords: muscle ; growth ; adrenergic agents ; clenbuterol ; propranolol
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The effect of propranolol on clenbuterol-induced changes in muscle fibre size and protein content were studied. Propranolol did not inhibit the ability of clenbuterol to stimulate protein accretion but reduced the increase in muscle fibre size. The compositional and physical characteristics of clenbuterol-induced muscle growth thus appeared to be separated by propranolol.
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  • 65
    ISSN: 1432-0878
    Keywords: Key words: Aesthetasc ; Chemoreception ; Dendrite Blue crab ; growth ; Olfaction ; Salinity adaptation ; Sensilla ; Callinectes sapidus (Crustacea)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The aesthetasc sensilla of the euryhaline blue crab, Callinectes sapidus, are innervated by the dendrites of from 40 to 160 bipolar chemosensory neurons. Each dendrite forms two cilia within the basal portion of the sensillum, and these subsequently branch yielding approximately 10 outer dendritic segments per neuron. Auxiliary cells surround the inner dendritic segments and also ensheathe the outer dendritic segments up to the terminus of the ”constricted region” (a zone in which there is a slight narrowing of the aesthetasc). Crystal violet staining suggesting access of odor stimuli is limited to that portion of the sensillum distal to the constricted region. In freshwater-acclimated blue crabs the length and level of branching in the dendrites extending beyond the constricted region is significantly reduced relative to that of seawater-acclimated animals (mean lengths: 150 µm versus 517 µm, respectively). After transfer of freshwater-acclimated crabs to seawater there is a rapid increase in length of the outer dendritic segments, reaching 60% of that for seawater-acclimated crabs by 48 h. A similar time course for regrowth is seen for seawater-acclimated crabs in which the outer dendritic segments have been osmotically ablated. Conversely, with rapid transfer of seawater-acclimated animals to lower salinities, there is a correspondingly rapid reduction in length of the outer dendritic segments. The reduced length of the outer dendritic segments in freshwater-acclimated animals may reflect the effective distance over which an appropriate osmotic/ionic microenvironment for neural function can be maintained within the aesthetasc.
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  • 66
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    Potato research 24 (1981), S. 183-186 
    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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  • 67
    ISSN: 1871-4528
    Keywords: sprouts ; food reserves ; growth ; branching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Zusammenfassung Der Verlauf des Keimwachstums wurde mit Knollen, die in verschiedenen Abständen vom keimenden Auge verletzt waren. untersucht. Die Inkubation erfolgte bei 12°C im Dunkeln in feuchtem ‘University of California’ Kompost. Obwohl die Steigerung des Keimtrockengewichtes mit der Zunahme an verfügbarem Knollensubstrat erhöht wurde, hatte die Verletzung noch einen zusätzlichen steigernden Einfluss, sowohl auf das Keimtrockengewicht als auch auf das Längenwachstum, das noch stärker gefördert wurde (Abb. 1). Wahrscheinlich sind sowohl das Ausmass der Verletzung als auch der Abstand der Verletzung vom Keim wichtig in bezug auf den Wachstumseinfluss. Der Einfluss der Grösse der Knollenstücke auf das Keimwachstum wurde ebenfalls untersucht. Zusätzlich zu der positiven Wirkung des steigenden Knollenstückgewichtes auf die Erhöhung des Keimtrockengewichtes zeigte sich noch ein weiterer Einfluss durch eine Vergrösserung des Knollenstückdurchmessers (Abb. 2). Wurden die Knollenstücke in Kompost gepflanzt, zeigte sich in bezug auf das Längenwachstum sowohl der Haupt-als auch der Seitentriebe ein umgekehrtes Verhältnis zum Frischgewicht der Knollenstücke, aber ein positives zum Durchmesser der Knollenstücke bei konstantem Frischgewicht (Abb. 3). Die Zahl der Seitentriebe pro Auge war mit dem Frischgewicht der Knollenstücke positiv korreliert.
    Abstract: Résumé La cinétique de la croissance du germe a été étudiée à l'aide de tubercules blessés à différentes distances des yeux, en maintenant des explantats à 12°C et à l'obscurité, dans un compost humide mis au point à l'Université de Californie. Bien que l'accumulation de matière sèche dans le germe ait été stimulée par l'augmentation du substrat assimilable provenant des gros explantats, la blessure a provoqué un effet cumulatif sur la teneur en matière sèche du germe et, de façon plus conséquente, sur son élongation (fig. 1). Il semble que l'importance de la blessure ainsi que sa distance par rapport à l'oeil jouent un rôle déterminant sur le dégré de réponse du germe. Des expériences ont également été réalisées sur des fragments de tubercules pour déterminer l'effet de la dimension de l'explantat sur la croissance du germe. En plus de l'effet positif sur la teneur en matière sèche, dû à l'augmentation du poids de l'explantat, on a observé un effet favorable lorsque le diamètre de ce dernier était plus élevé (fig. 2). Après plantation dans le compost, le taux d'élongation du germe principal et des germes ramifiés tendait à être inversé par rapport au poids frais de l'expplantat mais restait positif par rapport à son diamètre, à poids frais égal (fig. 3). Le nombre de ramifications par oeil était en relation directe avec le poinds frais de l'explantat.
    Notes: Summary Sprout dry weight accumulation was stimulated by an increase in the amount of tuber substrate available. Wounding had an additional promotory effect on both dry weight accumulation and extension growth. Sprout dry weight accumulation from tuber cores of the same fresh weight was enhanced by an increase in the diameter of the core when samples were planted either in perlite or UC compost. In compost, elongation rates of both main and branch sprouts were inversely related to core fresh weight but positively related to core diameter when fresh weight was kept constant. The number of branch sprouts per eye was positively related to core fresh weight.
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  • 68
    ISSN: 1871-4528
    Keywords: Solanum tuberosum L. ; temperature stress ; growth ; nutrient deficiency ; tuber analysis ; tuber size ; glasshouse ; growth room
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary To determine calcium fertility and high temperature effects on internal brown spot development in potato, cv. Russet Burbank plants were fertilised with Hoagland's nutrient solution with or without calcium. Prevalence and severity of internal brown spot were greatest in tubers receiving no calcium fertilisation during growth. Internal brown spot was evident as early as tuber initiation. A high growth medium temperature (32°C) at tuber maturity with a lack of calcium increased internal brown spot incidence and severity. No tubers subjected to the high temperature and fertilised with calcium developed internal brown spot. Peel calcium concentration of tubers receiving no calcium fertilisation was lower (0.5–0.8 g/kg) than tubers receiving calcium (1.2–1.9 g/kg). Medullary tissue calcium concentration was similar under both calcium regimes. Calcium availability during early tuber growth was an influential factor in internal brown spot development, however high temperature effects may not be discounted in exacerbating the disorder.
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  • 69
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    Plant systematics and evolution 165 (1989), S. 227-237 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Eucalyptus ; Eudesmieae ; Floral morphology ; calyx ; corolla ; operculum ; growth ; allometry ; convergence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In theEudesmieae B eucalypts and inEucalyptus caesia, the perianth of the mature flower consists of a single, anatomically continuous, opercular structure that is crowned by the tips of the original free and separate calycine and corolline whorls. Ontogenetic and comparative evidence supports the hypothesis that this operculum is mostly corolline in composition, and that the calycine parts have been elevated distally onto the dorsal surface. In theEudesmieae B eucalypts this condition appears to be due to precocious initiation of the corolline primordia, followed by expansion and continuity of their growth centres which incorporates the areas at or below the base of the still differentiating calycine whorl. InEucalyptus caesia the corolline primordia are not precocious, but a similar situation is effected by a seemingly retarded increase in receptacle diameter relative to lateral expansion of the corolline growth centre(s). In these two examples the same final perianth form apparently derives from two different sets of growth processes which, nonetheless, result in the same allometric relationships within the developing flower. Although identical at maturity, the operculum form in these two taxa is best described in terms of convergence, rather than homology.
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    Plant systematics and evolution 196 (1995), S. 195-206 
    ISSN: 1615-6110
    Keywords: Pteridophyta ; Dryopteridaceae ; Dryopteris filix-mas ; Clonal gametophytes ; growth ; reproduction ; genetic and environmental effects ; phenotypic plasticity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Artificially formed clonal gametophytes ofDryopteris filix-mas (L.)Schott were able to grow and reproduce, although growth rates, proportions of hermaphrodites and reproductive efforts were low. Variable density and nutrient levels appeared to affect gametophytic life histories and they continued to influence the viability of the developing sporophyte generation. Differences between populations and sporophytes were discovered in life histories. Hermaphroditic gametophytes were considerably larger and possessed higher viability than did males. Clear differences between clones in the level of phenotypic plasticity in gametophyte size were observed. No neighbor effect on gametophyte sex expression was detected with the densities and nutrient levels used.
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    Aquatic ecology 19 (1985), S. 179-181 
    ISSN: 1573-5125
    Keywords: zebra mussels ; polystyrene ; settlement ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth of settled and metamorphosed larvae of the zebra mussel (Dreissena polymorpha) is clearly retarded when polystyrene plates are used as a substrate compared with the growth of those forms attached to PVC plates. Possibly, low molecular weight compounds are released into the aquatic environment by the polystyrene and these materials may have a strongly adverse effect upon the growth of young zebra mussels. There is no difference in colonization of young mussels between PVC and polystyrene plates if these plates are sufficiently overgrown with bacteria and algae.
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  • 72
    ISSN: 1573-5176
    Keywords: Debromolaurinterol ; growth ; Laurencia ; laurinterol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth of Laurencia okamurae and the content of laurinterol and debromolaurinterol were influenced by various factors. Temperature influenced growth raere te with a maximum at 25°C, regardless of daylength. Maturity depended on temperature rather than daylength; the plants grew without maturing at 15°C, while the plants matured within two weeks at 25°C. The plants were able to grow at salinities of 14–50‰ with maximum growth at 26‰. The salinities growth rash;50‰te reduced with decreasing concentration of nitrate below 1.2 × 10-3 M, and of total phosphate below 7.5× 10-8 M. Bromide concentration had no effect on growth, and the plants grew without bromide. Variation in temperature between 15–25°C and daylength produced no obvious change in laurinterol and debromolaurinterol contents. On the other hand, an increase in salinity led to an increase for both. The plants cultured in a completely artificial medium, modified ASP12NTA, showed a marked drop in their content of these metabolites. An increase in concentrations of nitrate, total phosphate or bromide did not restore the content.
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  • 73
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    Journal of applied phycology 10 (1998), S. 547-554 
    ISSN: 1573-5176
    Keywords: herbicide ; green alga ; growth ; nutrients ; photosynthesis ; it Protosiphon botryoides ; respiration ; Thiobencarb
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of the herbicide thiobencarb (Saturn) were tested on the growth and physiology of the chlorophyte Protosiphon botryoides isolated from an Egyptian paddy. Assays were conducted using 16-day batch cultures. Chlorophyll and dry weight biomass yields were significantly reduced at 2–3 mg L-1 thiobencarb, and dark respiration increased and protein decreased significantly at 3 mg L-1. Reductions in exponential specific growth rate (μ) were generally small, but in some cases significant. Thiobencarb also slightly, but significantly, reduced the 77 K fluorescence parameter Fv/Fm, an indicator of maximum photosynthetic efficiency. No consistent dose-dependent changes occurred in chlorophyll per unit dry weight, total carbohydrate or gross photosynthetic capacity. Whereas half of the added thiobencarb was recovered from control (uninoculated) medium, it was largely absent from cells and culture medium after sixteen days, indicating biodegradation by the alga or associated bacteria. P. botryoides recovered fully within sixteen days following subculture in thiobencarb-free medium. Independently varying phosphate and nitrate nine-fold had no clear effect on the sensitivity of P. botryoides to thiobencarb.
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  • 74
    ISSN: 1573-5176
    Keywords: agar ; Gracilaria tenuistipitata ; growth ; salinity ; seawater pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Acclimation responses of the red alga Gracilaria tenuistipitata var. liui collected on the northwest coast of Philippines were determined in laboratory setups and outdoor cultivation tanks in Haifa, Israel. Growth under laboratory conditions was influenced by all three variables studied, namely, temperature (20 or 30 °C), salinity (20, 30 or39‰) and seawater pH (6.5, 7.0, 8.0 or ≥ 9.0). In 250 mL flasks lacking pH control growth was influenced by temperature only at 20 ‰, whereas at 39 ‰, growth rates were similar at 20 or 30 °C. In 500 mL cylinders in which pH was controlled, growth rates were significantly different at a pH of 6.5 and 7.0 for all salinities, with maximal rates occurring in 39 ‰. At pH 8.0, and above, growth rates between salinities were similar and reduced to approximately 50% at a pH of 9.0 compared to rates at a pH of 6.5. Photosynthesis responses generally resembled growth responses both, in 250 mL and 500 mL cultures. In 40-L outdoor tanks, weekly growth and agar yields were apparently enhanced by increasing light intensities (up to full sunlight) and nutrient concentrations (up to 0.2 mM PO3 2- and 2.0 mM NH4 +), and rates averaged four times higher than rates determined in the smaller flask cultures. This study shows broad salinity tolerance of G. tenuistipitata var. liui and its ability to sustain growth rates that are among the highest measured for Gracilaria spp. in outdoor cultures.
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  • 75
    ISSN: 1573-5125
    Keywords: growth ; Azolla ; eutrophication ; mercury ; India
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth ofAzolla was stimulated in different water bodies in Burdwan. It depended on the PO4−P contents of the media. Biomass, chlorophyll and tissue phosphorus content ofAzolla were positively correlated with PO4−P of the different water bodies while chlorophyll content of the fern was positively correlated with conductivity. We concluded that the water bodies of Burdwan can be utilised as sites for large scale multiplication ofAzolla for fertilization purposes in rice cultivation, despite the presence of mercury.
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  • 76
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    Journal of applied phycology 9 (1997), S. 19-24 
    ISSN: 1573-5176
    Keywords: Chaetoceros ; growth ; neutral lipid ; total lipid ; nitrogen deprivation ; Nile Red
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chaetoceros muelleri (Schütt) was cultured on a thermal gradient plate, subjected to two media types with a range of specific conductances, and evaluated for growth and neutral lipid accumulation. Growth was measured directly by daily changes in cell numbers and indirectly by changes in optical density at 750 nm. C. muelleri exhibited a growth rate of at least two doublings day-1 over broad temperature (20 to 35 °C) and conductance ranges (10 to over 60 mS cm-1) and the optimum growth rate approached 4.0 doublings day-1 at 30 °C and a conductance of 25 mS cm-1. Intracellular neutral lipid storage was evaluated with fluorometry and epifluorescent microscopy using the fluorochrome Nile Red. Gravimetric analysis revealed a total lipid content in nitrogen-depleted cultures of C. muelleri of over 400 mg L-1, five to seven times that observed in nitrogen-replete cultures. Based on its high growth rate, tolerance to a broad range of temperatures and specific conductances, and large quantity of intracellular lipid, C. muelleri may have potential for exploitation as a renewable precursor to liquid fuels or as a lipid source.
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  • 77
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    Journal of applied phycology 9 (1997), S. 437-444 
    ISSN: 1573-5176
    Keywords: Haematococcus pluvialis ; experimental design ; optimization ; culture medium ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A central composite rotatable design was used to examine the effects of five components of the medium on the growth of Haematococcus pluvialis in batch culture. The medium components considered were: sodium acetate,potassium nitrate, major elements, trace elements and vitamins. Within the range of the concentrations tested, a moderate concentration of the major elements significantly enhanced algal growth, both in terms of specific growth rate and cell dry weight, whereas the vitamins had no significant effect. Based on the response surface contour plots and the results of numerical analyses, the optimal nutrient concentrations for growth in terms of specific growth rate were 0.51 g L-1 sodium acetate, 0.25 g L-1 potassium nitrate, 0.63 mL L-1 of the major element stock solution and 0.2 mL L-1 of the trace element stock solution. The optimal nutrient concentrations for biomass production were 1.64 g L-1 sodium acetate, 0.37 g L-1potassium nitrate, 2.52 mL L-1 of the major element stock solution and 0.03 mL L-1 of the trace element stock solution.
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  • 78
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    Journal of applied phycology 9 (1997), S. 551-558 
    ISSN: 1573-5176
    Keywords: Spirulina ; Arthrospira ; growth ; salinity ; quantum yield ; nutrient status ; Chitu ; Ethiopia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Spirulina platensis (=Arthrospira fusiformis) was isolated from Lake Chitu, a soda crater lake in the Ethiopian Rift Valley, where it formsa dense and almost unialgal population. Growth experiments were run in turbidostats under constant light, to assess growth response and tolerance to salinity, as well as to the component anions. Salinity was tested over the range 13–88 g L-1 using additions of NaHCO3, NaCl or Na2SO4. A maximum specific growth rate (µmax d-1) of 2.14 was achieved at the lowest salinity, but quantum yield (Φ%) was highest between 33 to 51 g L-1. Increasing salinity of the medium reduced the specific growth rate (µ) to a minimum of 0.33 d-1, and Φ to 〈 0.5%. Growth response in terms of µ and Φ was best in HCO 3 - , less in Cl-, and least in SO 4 2- series. Cultures showed obvious differences in cellular morphology, pigment, nitrogen and phosphorus contents in response to treatment with the different anions. Results indicate that the species has a wide range of tolerance to salinity from NaHCO3. Some degree of tolerance is also shown to high concentrations of Cl- and SO 4 2 , but with an overall lower performance of cells in terms of growth rate, light utilization efficiency, and nutrient status to cells grown in high HCO 3 - concentrations and the same levels of salinity and light.
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  • 79
    ISSN: 1573-5125
    Keywords: eutrophication ; feeding ; growth ; Mytilus edulis ; validation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract EMMY is an ecophysiological model of the growth and reproduction of a single mussel (Mytilus edulis L.). It contains feedback loops in the uptake and metabolism of food and in the partitioning of carbon and nitrogen to the internal state variables somatic tissue, storage, organic shell matrix and gametes. In this paper EMMY is used to simulate individual mussel growth in a series of mesocosm experiments with different inorganic nutrient loads (N and P). The experiments explore the impact of eutrophication reduction scenarios on mussel growth under defined and controlled conditions. In earlier studies EMMY was calibrated using expert knowledge on growth and reproduction during a period of 5 years. The resulting calibrated model was validated for system inputs and observations of three ecosystems with significantly different food and silt concentrations. EMMY reproduced the mussel growth sufficiently accurate in ecosystems with moderate or high food concentrations. In this study EMMY was adapted in order to cope with low food concentrations, then recalibrated (using the original calibration data and procedure) and applied without further calibration to 3 replicated mesocosm experiments. The EMMY simulations in this study show the ecophysiological response of mussels to different food (phytoplankton and detritus) concentrations. It is concluded that the mussels can adapt to significantly reduced food concentrations, due to inorganic nutrient load reduction, and still maintain growth.
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  • 80
    ISSN: 1573-5176
    Keywords: cyanobacteria ; blue-green algae ; biosynthesis ; growth ; gamma linolenic acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The total lipid and fatty acid content ofSpirulina platensis UTEX 1928 was 7.2 and 2.2% respectively of cellular dry weight under controlled conditions supporting high growth rates. With increases in irradiance from 170 to 870 μmol photon m−2 s−1, growth rate increased, total lipid decreased, and fatty acid composition was unaffected. At 1411 μmol photon m−2 s−1, total lipid increased slightly and percent composition of the fatty acid gamma linolenic acid increased. Growth and total lipid content ofS. platensis were affected by changes in growth temperature from 25 to 38 °C. With increased growth rate, total lipid content increased. This suggests that the storage of carbon increases at temperatures supporting high growth rates. The degree of saturation increased with temperature. Although the percent composition of gamma linolenic acid was higher at lower growth temperature, production was still primarily a function of growth rate. The effect of temperature on fatty acid content and degree of saturation was of secondary importance. Nitrogen starvation increased total lipid content but decreased fatty acid content as a percentage of dry weight; composition of the fatty acids was unaffected. N-starvation appeared to suspend synthesis of long chain fatty acids inS. platensis, suggesting that some other compound stores fixed carbon when nitrogen is limiting. It was concluded that fatty acid production inS. platensis is maximized by optimizing culture conditions for growth.
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  • 81
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    Journal of applied phycology 8 (1996), S. 421-430 
    ISSN: 1573-5176
    Keywords: Gracilaria gracilis ; suspended cultivation ; vegetative propagation ; South Africa ; yield ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Rope rafts were used to evaluate the growth of localGracilaria gracilis at Saldanha Bay, on the west coast of South Africa, over four years. The plants were grown on horizontally-suspended ropes or netting lines. Relative Growth Rates (RGR) of plants on ropes with low stocking weights often exceeded 10% d−1 in (austral) summer, and fell to between 6 and 7.5% d−1 in winter. Commercial-style lines of plastic netting stocked at 400 g m−1 and placed 0.75 m apart yielded a mean of about 2 kg m−2 30 d−1, with a mean RGR of about 5% d−1 over a two-year period. Various methods of improving yields were tested, including attaching floats to individual lines and optimising stocking weight. In Saldanha Bay in late summer, warm, oligotrophic water can severely reduce growth. Growth was optimised by growing the plants as close as possible to the surface (0.2 m), where water motion, and by implication, nutrient uptake, are higher. Agar content and gel strength generally remained high all year round. The potential for commercial production is evaluated in the light of these results.
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  • 82
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    International journal of anthropology 1 (1986), S. 107-112 
    ISSN: 1824-3096
    Keywords: growth ; shape and size ; Spanish population
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    Topics: Biology
    Notes: Abstract In this work the analogies and differences in shape and size between a rural school population (6–14 aged) of the Lozoya-Somosierra region (Madrid) and several recent and past Spanish populations from different environments have been studied. The results show the growth trend as well as the influences of ecological and socioeconomical factors.
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  • 83
    ISSN: 1573-0778
    Keywords: batch culture ; conditioned medium ; growth ; hybridoma ; inoculum ; protein productivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Apart from gas concentrations, temperature, and pH, generally only the initial conditions can be manipulated in batch culture. Inoculum size and initial conditioned medium concentration represent two important considerations for optimal batch production. Two hybridoma cell lines were used to assess the impact of these initial conditions on population growth and monoclonal antibody productivity in suspension batch culture. Varying initial cell concentration over the range of 1.0 × 105 cells mL-1 to 3.0 × 105 cells mL-1 did not affect maximum product titre or maximum volumetric cell-hours attained. Initial percent of conditioned medium up to 40 percent strongly impacted on population growth and productivity, with initial levels of 30 to 40% conditioned medium reducing or eliminating lag phase and increasing average viable cell density. However, specific productivity and product titre declined with increasing initial percent conditioned medium, even on a per volume of fresh medium basis. Glutamine and glucose depletion or ammonia toxicity could cause depressed product titres when conditioned medium is used. Glutamine and glucose levels can easily be replenished in conditioned medium at minimal cost, and ammonia can be removed. Specific productivity was higher during cyclic batch operating mode than during batch operating mode. This may be because cyclic batch operating mode results in an incidental volume of conditioned medium at the beginning of each cycle. A two stage, cyclic-batch/batch operating mode can be employed to fully utilize medium and maximize product titre.
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  • 84
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    Journal of applied phycology 11 (1999), S. 293-299 
    ISSN: 1573-5176
    Keywords: organismic determinants ; Gracilaria gracilis ; Rhodophyta ; regeneration ; growth ; mariculture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth of Gracilaria gracilis (Stackhouse) Steentoft, Irvine et Farnham was examined by studying the effect of organismic determinants such as thallus length, position along the thallus and branching. Knowledge of these factors is essential in order to increase production from suspended seaweed rafts seeded with vegetative G. gracilis fragments. Seeding netlons with seaweed material freshly collected from subtidal populations provided up to 30% higher relative growth rates than seaweed maintained on the netlons for successive months. Initial seedstock length greatly affected growth rates and yields such that 30-cm thalli fragments resulted in growth rates 14% higher than for 10-cm fragments. This difference is suggested to be due to the higher contribution to overall biomass by growth of lateral branches. Comparisons of the growth of apical and basal fragments suggest that growth takes place over the entire length of the thallus, but that the apex contributes more to overall elongation than does the proximal part. The removal of apical meristems resulted in an enhanced branching frequency with production of four times as many branches as intact fragments. Evidence is also provided for extensive morphological differentiation following long periods of rapid growth. These thalli have very high frequency of branching, are hollow due to the disintegration of medullary cells and are considered to be completely senescent. These factors have implications for the successful cultivation of G. gracilis on commercial mariculture systems.
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  • 85
    ISSN: 1573-5125
    Keywords: Marenzelleria ; Polychaetes ; macrozoobenthos ; abundance ; biomass ; population dynamics ; growth ; secondary production ; Baltic Sea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The propagation of an immigrant from North America, viz. the spionid Marenzelleria cf. viridis in the Darss-Zingst Bodden (DZB) (southern Baltic Sea), was studied at three stations from March 1992 to December 1995. Highest mean abundances (over 28 000 ind. m-2) and wet weights (400 g m-2) were recorded at station 2 in 1994. The spionid also reached its highest dominances in terms of biomass (40 to 90%) at this station, which was selected for the population dynamics, growth and secondary production studies. The spionid has a life span of about 3 years, and many individuals achieved sexual maturity after one year. Their growth curve is steepest during the first year of life, during which the animals grow to a length of about 180 segments. However, growth depression was observed during the ripening of the gametes in April, May and June. Secondary production was in the region of 55 to 85 g AFDW m-2 y-1. Productivity (P/B) varied considerably from generation to generation, ranging between 0 and 4.8 with an average between 1.2 and 1.6.
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  • 86
    ISSN: 1573-5176
    Keywords: Rhodophyceae ; Calliblepharis jubata ; growth ; carrageenan
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    Topics: Biology
    Notes: Abstract Study of the seasonal variation in the quality and content of iota carrageenan inCalliblepharis jubata from the Normandy coast of France shows that seasonal fluctuation of the environment affects the growth and chemical composition of this red alga. Growth increases during winter, when there is little synthesis of carrageenan and floridean starch is accumulated. When inorganic nitrogen content decreases, growth also decreases and stops (May to August); with high light intensity, the metabolism is oriented towards a synthesis of parietal carrageenans to the detriment of the reserve products such as floridean starch.
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  • 87
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    Journal of applied phycology 8 (1996), S. 87-103 
    ISSN: 1573-5176
    Keywords: Ascophyllum nodosum ; growth ; harvesting effects ; reproduction ; season ; survival
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Although populations ofAscophyllum nodosum are harvested commercially, little is known about the effects on demographic vital rates (growth, reproduction, survival). This study examines the effects of harvesting season and harvesting intensity on growth, reproduction and mortality of intact fronds in four size classes and in fronds truncated by the harvest. Knowledge of size-specific vital rates was used to evaluate the response of the population to harvesting. Harvesting season and harvesting intensity did not exert a significant effect on growth. Growth in plots not subject to harvesting was less than in harvested plots. No major differences in growth, reproduction and survival between intact and severed fronds emerged. The number of fronds attaining reproduction was enhanced by increased harvesting intensity and by cutting in summer. Harvesting did not seem to induce breakage, and breakage appeared higher in the uncut plots. Most harvesting treatments did not influence survivorship and survivorship was similar among all size classes. Growth rates were inversely related to sizes of fronds. Assessment of variation across size classes yielded more accurate estimates of growth rates than those of previously used methods. Accurate size class specific-growth rates will be a useful criterion when regulating intervals between harvests. Furthermore, assessment of size-specific vital rates allows identification of the frond size classes most relevant to the preservation of resources. Because of their fast growth rates and abundance, fronds in class 1, and, to a lesser extent, class 2, are responsible for most of the population regrowth after harvest. In contrast, classes 3 and 4 contribute little to recovery. This finding provides a strong basis for a harvesting strategy that targets the largest fronds.
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  • 88
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    Cytotechnology 20 (1996), S. 13-22 
    ISSN: 1573-0778
    Keywords: insect tissue culture ; cell-specific lines ; survival ; growth ; cell differentiation ; applications
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Conclusion Current methods of insect cell culture have produced a limited variety of cell types in an ever expanding list of insect cell lines. In developing midgut epithelial cell lines, we found that traditional methods in insect cell culture failed to provide healthy cells from mature tissues. Examination of mammalian cell culture literature for this particular cell type provided the insight required to successfully develop a cell-specific line (Baines et al., 1994). The potential applications for cell-specific lines from insects are numerous. This paper is a compilation of ideas that will hopefully enable other researchers to develop additional cell-specific lines.
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  • 89
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    Aquatic ecology 21 (1987), S. 141-147 
    ISSN: 1573-5125
    Keywords: Phaeocystis pouchetii ; P.globosa ; temperature tolerances ; colony shapes ; growth
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    Topics: Biology
    Notes: Abstract An Arctic clone ofPhaeocystis pouchetii LAGERHEIM was compared toPhaeocystis globosa SCHERFFEL isolated from the southern North Sea with regard to temperature tolerance and colony shapes. Already youngP.pouchetii colonies (〈100 μm) show the typical distribution of the cells in groups, separated from each other by wide zones of cell-free mucilage; the maximum colony size is ca 2 mm in diameter.P.pouchetii colonies form clouds with bubble-like vesicles, spherical colony-shapes are seldom found.P.globosa colonies are spherical up to a size of 2 mm; the cells are distributed homogeneously over the periphery of the colonies. A ‘pouchetii’-like distribution of cells never occurs either in the spherical young colonies or in the pear-shaped old colonies (size up to 8 mm). A development from the colony shape of the ‘globosa’-type to the ‘pouchetii’-type or vice versa was never found. Therefore the colony shape has to be considered a constant distinctive character. Single cells ofP.pouchetii andP.globosa cannot be separated from each other by using the light microscope; this also holds for the flagellates and the non-motile cells.P.pouchetii grows well between 0°C and 14°C,P.globosa between 4°C and 22°C, respectively. Because of the distinctive differences in the morphology of the colonies and the differences in temperature tolerances we propose thatPhaeocystis globosa should no longer be considered conspecific withPhaeocystis pouchetii.
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  • 90
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    Journal of applied phycology 11 (1999), S. 551-558 
    ISSN: 1573-5176
    Keywords: Nodularia ; growth ; hepatotoxin production ; nodularin ; salinity ; irradiance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The objective of this work was to determine the influence of total dissolved solids/salinity (TDS mgL-1) on growth and biomass specific rates of nodularin (hepatotoxin) production by Nodularia spumigena 001E isolated from Lake Alexandrina, South Australia. Maximum biomass yield (dry matter, chlorophyll a and particulate organic carbon/POC) at 80 μmol photon m-2 s-1 was recorded at 3300 mg TDS L-1 and decreased at salinities above or below this value (p 〈 0.05). The maximum biomass yield (dry matter and chlorophyll a) at 30 μmol m-2 s-1 occurred at a higher salinity of 9900 mg TDS L-1. Cultures grown at 80 μmol m-2 s-1, at a TDS〉 6600 mg L-1, had significantly (p 〈 0.05) lower nodularin content (ml-1 medium) than cultures grown at the same salinities at 30 μmolm-2 s-1. The maximum total toxin concentration (mL-1 medium) occurred at 9900 and 3300 mg TDS L-1 at 30 μmol m-2 s-1and 80 μmol m-2 s-1 respectively. Toxin per unit biomass, expressed as dry matter, chlorophyll a and POC was similar for cultures grown at 30 μmol m-2 s-1 or 80 μmol m-2s-1 at salinities 〈 6600 mg TDS L-1. At salinities 〉 9900 mg TDS L-1 the toxin content per unit biomass decreased at both irradiances, however, cultures grown at 30 μmol m-2s-1 had a higher toxin content than those grown at 80 μmol m-2 s-1. The results indicate that not only do changes in irradiance and salinity directly influence growth and toxin production but that changes in irradiance affected the influence of salinity.
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  • 91
    ISSN: 1573-5125
    Keywords: Marenzelleria cf. viridis ; Polychaetes ; food limitation ; food selection ; growth ; gut passage time ; food quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phytoplankton 〈 20 µm was a principal dietary component of the larvae of Marenzelleria cf. viridis. Maximum ingested particle size increased as animal size increased, reaching a maximum diameter of 80 µm for larvae with 6 to 10 setigers. The larvae started ingesting particulate matter at the 1-setiger stage and were able selectively to ingest phytoplankton and polystyrene particles of various sizes. Larvae in the 6 to 10-setiger size group did not differ from those in the 11 to 17-setiger size group in respect of size selectivity for polystyrene particles. The gut passage time for Chlorella vulgaris was ≥ 20 min. The ingestion rate was limited by food concentrations even at concentrations much higher than those encountered in the natural biotope, saturation being reached at a concentration of 28.5 times 106 cells ml-1 (117.7 mg C l-1. The low maximum filtration rate of only 1.19 µl ind.-1 h-1 indicates that the filtering capacity of the larvae is low. The larvae are still capable of food uptake at 1 °C. Further experiments demonstrated that larval growth and survival were strongly dependent on both food concentration and quality. Larval growth was food-limited under biotope conditions of the Darss–Zingst Boddens and even more so under Baltic Sea conditions. The results indicate that Marenzelleria cf. viridis is a species adapted to eutrophic conditions prevailing in brackish waters.
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  • 92
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    Aquatic ecology 32 (1998), S. 261-279 
    ISSN: 1573-5125
    Keywords: phosphorus ; fatty acid ; growth ; life history ; food limitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Evidence suggests that marine and freshwater zooplankton generally experience food levels above subsistence values in terms of carbon. However, the quality of this food may be poor due to an insufficiency of other essential nutrients. In this review, we examine recent progress in three main areas of food quality research: (1) elemental (especially P) limitation, (2) digestion resistance, and (3) biochemical (especially fatty acids) limitation. We evaluate laboratory and field evidence in each of these areas, look at new evidence about the life history implications of the elemental limitation hypothesis, and suggest future avenues for research. From a rather large number of seemingly heterogeneous studies, a single consistent picture of food quality emerges: both P and essential fatty acids are predicted to be important dietary factors, but at different places and times. Nevertheless, despite an abundance of valuable laboratory studies, our knowledge of food quality limitation in the field is still poor.
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  • 93
    ISSN: 1573-5176
    Keywords: microalgae ; temperature ; growth ; total lipids ; fatty acids ; tropical mariculture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of temperature from 10 °C to 35 °C on the growth, total lipid content, and fatty acid composition of three species of tropical marine microalgae, Isochrysis sp., Nitzschia closterium, N. paleacea (formerly frustulum), and the Tahitian Isochrysis sp. (T.ISO), was investigated. Cultures of N. closterium, Isochrysis sp. and T.ISO grew very slowly at 35 °C, while N. closterium did not grow at temperatures higher than 30 °C or lower than 20 °C. N. paleacea was low-temperature tolerant, with cells growing slowly at 10 °C. N. paleacea produced the highest percentage of lipids at 10 °C, while the other species produced maximum amounts of lipid at 20 °C. None of the species maintained high levels of polyunsaturated fatty acids (PUFAs) at high growth temperature and there was a significant inverse relationship between the percentage of PUFAs and temperature for N. paleacea. A curved relationship was found between temperature and percentage of PUFA for N. closterium and tropical Isochrysis sp., with the maximum production of PUFA at 25 °C and 20 °C, respectively. The two Nitzschia species produced higher levels of the essential fatty acid eicosapentaenoic acid [20:5(n-3)] at lower growth temperatures, but the two Isochrysis species had little change in percentage of 20:5(n-3) with temperature. Only T.ISO had the highest percentage of 22:6(n-3) at lowest growth temperature (11.4% total fatty acids at 10 °C).
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  • 94
    ISSN: 1573-5176
    Keywords: Lyngbya wollei ; paralytic shellfish poisons ; growth ; toxin production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Collections of Lyngbya wollei were taken from Guntersville Reservoir, Alabama, over a period of three years. Healthy filaments were isolated and transferred to agar plates of Z-8 and LM6E media. Unialgal isolates were cultured for the study of growth and paralytic shellfish poison (PSP) production. Filaments were extracted and the toxins were detected using high performance liquid chromatography (HPLC) with post column oxidation followed by fluorescence detection. HPLC profiles show that laboratory cultures of L. wollei produced decarbamoyl gonyautoxin 2 and 3, plus several other PSP like toxins whose structures are under investigation. At 26 °C and a light intensity of 11 or 22 µmol m-2 s-1 optimum production of both biomass and toxins occurred. A decrease or increase in temperature or light flux caused a reduction in dry weight or toxicity. Compared to control levels, lower PO4-P and NO3-N and higher calcium levels gave rise to higher biomass and toxicity. Lower calcium, calcium- or PO4-P deficient medium and high NO3-N or PO4-P caused a large decrease in dry weight and toxicity.
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  • 95
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    Bulletin of experimental biology and medicine 103 (1987), S. 699-703 
    ISSN: 1573-8221
    Keywords: capillary ; colchicine ; proliferation ; cornea ; growth
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    Topics: Biology , Medicine
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  • 96
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    Bulletin of experimental biology and medicine 98 (1984), S. 1159-1161 
    ISSN: 1573-8221
    Keywords: motor response ; growth ; catecholamines
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    Topics: Biology , Medicine
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  • 97
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    Journal of pharmacokinetics and pharmacodynamics 10 (1982), S. 335-348 
    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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  • 98
    ISSN: 1573-8477
    Keywords: amphibian ; body size ; clonal ; genetic compatibility ; growth ; hybridogenesis ; local adaptation ; metamorphosis ; Rana esculenta ; tadpole
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Hybridogenetic species possess a hybrid genome: half is clonally inherited (hemiclonal reproduction) while the other half is obtained each generation by sexual reproduction with a parental species. We addressed the question of whether different hemiclones of the hybridogenetic water frogRana esculenta are locally adapted for genetic compatibility with their sexual parental hostRana lessonae. We artificially crossedR. esculenta females of three hemiclones (GUT1, GUT2 and GUT3) from a pond near Gütighausen, Switzerland and one hemiclone (HEL1) from near Hellberg, Switzerland each toR. lessonae males from both populations. We also created primary hybrids by crossing the sameR. lessonae males from both populations toR. ridibunda females from Poznań, Poland (POZ). Tadpoles were then reared in the laboratory at two food levels to assess their performance related to early larval growth rate, body size at metamorphosis and length of the larval period. Tadpoles from hemiclones GUT1, GUT3 and POZ had higher growth rates than those from hemiclones GUT2 and HEL1 at the low food level, but at the high food level all growth rates were higher and diverged significantly between hemiclones GUT2 and HEL1. Tadpoles from the intrapopulational crosses GUT2 × GUT and HEL1 × HEL were larger at metamorphosis than those from the interpopulational crosses GUT2 × HEL and HEL1 × GUT. A high food level increased the size at metamorphosis in all tadpoles. A high food level also decreased the days to metamorphosis and tadpoles from GUT1, GUT3 and POZ had the shortest larval period whereas those from GUT2 and HEL1 had the longest. These results indicate that the differential compatibility of clonal genomes may play an important role in hybridogenetic species successfully using locally adapted sexual genomes of parental species and that interclonal selection is likely important in determining the distribution of hemiclones among local populations.
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  • 99
    Electronic Resource
    Electronic Resource
    Springer
    Water resources management 13 (1999), S. 73-84 
    ISSN: 1573-1650
    Keywords: chlorophyll ; growth ; rice crop ; spectral reflectance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract Relations among spectral reflectance, chlorophyll ‘a’, and growth of rice plants grown on irrigated light textured soil in a semi arid region are presented here. There was a linear relation between spectral reflectance and rice plant height (r = 0.97), for band 1 (0.45–0.52 μm) reflectance values. On the other hand, in bands 2 (0.52–0.60 μm) and 3 (0.63–0.69 μm), reflectance values decreased until 70 days after planting (DAP) and then increased during the reproductive phase of the crop. The near infrared band 4 (0.76–0.90 μm) showed a maximum reflectance at 59 DAP (panicle initiation stage) and a decline in reflectance thereafter through maturity. The peak value of IR/R ratio was 16.39 at 62 DAP during the early reproductive phase; thereafter, it declines gradually with the maturity of the crop. Chlorophyll ‘a’ concentration was high during early growth (vegetative and early reproductive stages) and decreased during the flowering and maturity stages. The rice plant canopy show a high chlorophyll ‘a’ concentration at 64 and 59 DAP for sites A and B, respectively. Chlorophyll ‘a’ concentration is higher in site A plant canopies than it is in site B during the entire crop cycle. A good inverse correlation (r = 0.91) has been found between chlorophyll ‘a’ and band 1, while the IR/R ratio and the normalised difference vegetation index (NDVI) showed a relationship (r = 0.78) with the chlorophyll ‘a’ concentration during the crop cycle. Band 2, 3 and 4 radiance values show a biphasic linear relationship with chlorophyll ‘a’ concentrations, negative for early growth and positive for flowering and maturity stages. Results indicate that the period between 66 to 70 DAP is most suitable for the assessment of rice crop yield, based on chlorophyll ‘a’ concentration.
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  • 100
    Electronic Resource
    Electronic Resource
    Springer
    Aquaculture international 7 (1999), S. 251-260 
    ISSN: 1573-143X
    Keywords: bacterial biofilm ; common carp (Cyprinus carpio) ; growth ; rohu (Labeo rohita) ; Tilapia (Oreochromis mossambicus)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Experiments were conducted to enhance the growth of common carp (Cyprinus carpio), rohu (Labeo rohita) and Mozambique tilapia (Oreochromis mossambicus) through use of sugarcane bagasse as substrate. Bagasse was suspended in water with or without supplementation with fertilizers. Bagasse supplemented with cattle dung and urea favoured higher zooplankton production and significantly (p 〈 0.05) increased fish growth by over 50% compared to bagasse or fertilizers on their own. This higher production of fish is attributed to bacterial biofilm promoted on the substrate which, apart from forming food for zooplankton and fish, contributed to improved water quality by lowering ammonia.
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