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  • evolution  (693)
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  • Springer  (1,371)
  • American Chemical Society
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  • 1
    Electronic Resource
    Electronic Resource
    Einflüsse purinreicher Ernährung auf Gewichtsentwicklung, Kataboliten im Blutplasma und den Harnsäuretransport von Erythrozyten — eine Modellstudie an Hunden (1990)
    Springer
    European journal of nutrition 29 (1990), S. 135-146 
    Details
    ISSN: 1436-6215
    Keywords: purinreiche Nahrung ; Wachstum ; Metaboliten ; Harnsäuretransport ; Hund ; purine-rich diet ; growth ; metabolites ; uric acid transport ; dog
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary In a nutritional tolerance study 36 young dogs were fed over 52 weeks high or low purine diets at an average paired feeding intake of 0.6 and 80 mg purine-N/MJ per day. The high purine diet resulted in a significant decrease of growth rate by −23 % (Beagles) and −38 % (Dalmatians) and of feed efficiency (−29 and −42 %). The fasting levels of allantoin, uric acid and uracil in blood plasma were significantly increased. During the experiment a metabolic adaptation to the high purine diet decreased the plasma concentrations of uric acid, uracil and in part of allantoin. The high purine diet effected a significant increase of Km (2.5-fold) and of Vmax (1.6-fold) of uric transport through the erythrocyte membrane. The results documented disadvantageous effects of high purine nutrition during juvenile development.
    Notes: Zusammenfassung In einer Verträglichkeitsstudie erhielten 36 junge Hunde über 52 Wochen eine purinreiche oder purinarme Diät mit durchschnittlich 6 bzw. 80 mg Purin-N/MJ pro Tag bei gruppengleicher Aufnahme („paired feeding“). Die Hochpurin-Diät führte zu einer signifikanten Verminderung der Gewichtsentwicklung um −23% (Beagles) bzw. −38% (Dalmatiner) und der Futterverwertung (−29 bzw. −42%) sowie zu einer signifikanten Erhöhung der Nüchternwerte von Allantoin, Harnsäure und Uracil im Blutplasma. Während der Versuchsdauer machte sich eine metabolische Adaptation an die Hochpurin-Diät mit signifikanter Erniedrigung von Harnsäure, Uracil und teils auch Allantoin im Plasma bemerkbar. Die Hochpurin-Diät bewirkte eine signifikante Zunahme der Km (2,6fach) und Vmax (1,6fach) des Harnsäuretransports durch die Erythrozytenmembran. Die Ergebnisse belegen nachteilige Effekte purinreicher Ernährung während der Jugendentwicklung.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02021669
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  • 2
    Electronic Resource
    Electronic Resource
    Partitioning of fat and protein in energy retention of growing animals (1997)
    Springer
    European journal of nutrition 36 (1997), S. 299-302 
    Details
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01617802
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  • 3
    Electronic Resource
    Electronic Resource
    Nutrient intake and protein metabolism: responses to feeding (1997)
    Springer
    European journal of nutrition 36 (1997), S. 332-335 
    Details
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01617817
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  • 4
    Electronic Resource
    Electronic Resource
    Convergence across industrialised countries (1890–1989): new results using time series methods (1999)
    Springer
    Empirical economics 24 (1999), S. 23-44 
    Details
    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.)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001810050042
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  • 5
    Electronic Resource
    Electronic Resource
    Die Lage der Vogelsystematik (2000)
    Springer
    Journal of ornithology 141 (2000), S. 263-274 
    Details
    ISSN: 1439-0361
    Keywords: Systematics ; evolution ; anagenesis ; genealogy ; reference system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Verglichen mit anderen Tiergruppen, scheint die artliche Bestandsaufnahme der rezenten Vögel nahezu abgeschlossen zu sein. Doch ist das System der Vögel weiterhin umstritten und mit vielen Neuerungen konfrontiert. Die Gründe dafür liegen hauptsächlich in neuen, vor allem molekularbiologischen Methoden und in den unerwartet reichen Fossilfunden der jüngsten Zeit. Als Beispiele werden Altgaumenvögel, Kranichvögel, Ibisse, Flamingos, Mausvögel, Hopfe und Sperlingsvögel kurz behandelt. Die hier erzielten Fortschritte lassen die Befürchtung Stresemanns, die Großsystematik der Vögel sei mit den vorhandenen Methoden phylogenetisch nicht interpretierbar, zunächst als unbergründet erscheinen. Doch erwachsen einer solchen Interpretation andere Hindernisse, deren Bedeutung bisher zu wenig beachtet wurde, nämlich Parallelentwicklungen, die viel verbreiteter sind als gemeinhin angenommen. Ihre Häufigkeit lässt sich sogar mit evolutionsbiologischen Argumenten begründen. Es ist deshalb nicht zu erwarten, dass die Diskussionen um das „richtige“ System bald verstummen. Um dennoch die Eindeutigkeit der Information in nicht-systematischen Veröffentlichungen zu wahren, wird empfohlen ein etabliertes Referenzsystem auf Zeit zu wählen.
    Notes: Summary Unlike in most animal classes the inventory of extant species of the class Aves seems to be almost complete. Nevertheless avian systematics is challenged by many novelties and seems far from being settled. This is caused mainly by the application of novel methods of molecular analysis to phylogenetic problems and by the unexpectedly rich fossil record collected within the last 10–20 years. Examples from the Palaeognathae, Gruiformes, Threskiornithidae, Phoenicopteridae, Coliiformes, Upupiformes and Passeriformes are briefly treated. The progress in the field seems to disprove Stresemann's pessimistic view that the phylogeny of higher categories (orders) cannot be reconstructed by the available methods. However, phylogenetic interpretations are impeded by obstacles not considered by Stresemann and highly underestimated in most cases, namely by multiple independent developments leading to identical features. Frequent parallel developments are to be expected for theoretical evolutionary reasons. The diagnosis of such homoplasies can be extremely difficult or even impossible. Therefore we cannot expect the discussion about the “best” system of birds to end in the near future. Considering this dynamic situation in systematics, it is recommended to maintain unambiguousness of information in not strictly systematic publications by refering to a well established system as a temporally limited reference.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02462236
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  • 6
    Electronic Resource
    Electronic Resource
    Grapevine leaf gas exchange, plant growth, yield, fruit quality and carbohydrate reserves influenced by the grape leafhopper,Empoasca vitis (1993)
    Springer
    Entomologia experimentalis et applicata 69 (1993), S. 289-296 
    Details
    ISSN: 1570-7458
    Keywords: Vitis vinifera ; Empoasca vitis ; leafhopper ; photosynthesis ; transpiration ; stomatal conductance ; mesophyll conductance ; growth ; yield ; fruit quality ; starch ; carbohydrate reserves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The impact of the grape leafhopper,Empoasca vitis, on leaf gas exchange, plant growth, yield, fruit quality and carbohydrate reserves of the grapevines,Vitis vinifera L., was studied. Gas exchange was measured on the discolored (red) and the green parts of infested main leaves and on leaves from uninfested vines. Photosynthesis and mesophyll conductance were severely reduced on main leaves showing leafhopper feeding symptoms. The stomatal conductance of the red leaf section of infested main leaves was lower than on undamaged control leaves. Additionally, the red leaf section of infested main leaves showed lower transpiration rates when compared to the green parts of the same leaves and to undamaged control leaves. Gas exchange processes of lateral leaves were not affected by leafhopper feeding. Leafhopperload on main leaves was correlated to visual damage symptoms. At 71.8 leafhopper-days per leaf up to 40% of the main leaf area of the infested plants was discolored from the borders towards the center. Lateral leaves showed no feeding symptoms. Shoot diameter, pruning weight and carbohydrate reserves in the wood were not affected by leafhoppers. Lateral leaf area growth was significantly stimulated on plants infested by leafhoppers. No decrease in yield and fruit quality with leafhopper-loads up to 71.8 leafhopper-days per leaf were observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02382000
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  • 7
    Electronic Resource
    Electronic Resource
    Are the oviposition traits of the South India strain of Callosobruchus maculatus maintained by natural selection? (1990)
    Springer
    Entomologia experimentalis et applicata 57 (1990), S. 143-150 
    Details
    ISSN: 1570-7458
    Keywords: Bruchidae ; Callosobruchus maculatus ; competition ; development ; evolution ; fecundity ; growth rates ; host preferences ; life tables ; mortality ; natural selection ; net reproductive rate ; oviposition traits
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Le taux partiel de reproduction nette (R inf0 sup* ) dépend de l'espèce de la plante sur laquelle les œufs sont pondus et du nombre de larves entrant dans la graine. La survie larvaire est réduite par 1/(le nombre de larves par graine) parce qu'une seule larve se développe dans une graine. La fécondité n'est pas modifiée par la compétition subie par les larves, la mortalité larvaire a l'effet le plus important sur R inf0 sup* . Les femelles éliminent ou réduisent la compétition larvaire en dispersant leurs œufs uniformément et font si peu d'erreurs avec une hyperdispersion que l'évolution d'un comportement plus précis n'accroîtrait R inf0 sup* que de 4% au maximum. Des femelles retournant à une distribution des œufs au hasard provoqueraient une réduction de R inf0 sup* de 25% au moins. Les légumineuses généralement cultivées dans l'Inde du Sud sont des hôtes acceptables quand elles sont présentées seules. Le choix des femelles entre 2 hôtes élève R inf0 sup* de 30% ou plus par rapport à une distribution au hasard. Les préférences les plus nettes concernent des combinaisons présentant la plus grande différence de R inf0 sup* . Les femelles qui hyperdispersent leurs œufs, choisissent leurs hôtes et évitent les pertes par compétition en empêchant que les œufs ne donnent plus de descendants que ne le ferait une ponte au hasard. Les particularités de la ponte sont variables et héritables. Les lignées se sélectionnent bien, en fonction de la dispersion de leurs œufs sur les graines, de la discrimination des plantes hôtes, et de la modulation de leur taux de ponte. La sélection naturelle maintient ces particularités du comportement d'une façon sédentaire.
    Notes: Abstract The deposition of eggs by this strain of Callosobruchus maculatus (Fab.) (Bruchidae: Coleoptera) departs from randomness in three ways; eggs are uniformly dispersed, oviposition rates drop when beans begin to carry 2 or more eggs, and there are sharp host preferences. Using random egg placement for the unspecialized condition, these traits are evaluated for their effect on a female's contributions of offspring to the next generation (R0, the net reproductive rate). The major increases in R0 result from females dispersing eggs so uniformly that larval competition is either reduced or eliminated. Females reduce their oviposition rate when the larva from an egg added to a bean is almost certain to die in competitive encounters. Host preferences and larval survival in a host are positively associated with the abundance of the host in South India. The three oviposition traits act together to give and R0 that is 25–50% than that of eggs placed at random. These traits are known to be variable and heritable, hence, the conditions necessary for natural selection are statisfied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00343502
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  • 8
    Electronic Resource
    Electronic Resource
    Oviposition plant preference and offspring performance in the comma butterfly: correlations and conflicts (1996)
    Springer
    Entomologia experimentalis et applicata 80 (1996), S. 141-144 
    Details
    ISSN: 1570-7458
    Keywords: Polygonia c-album ; Nymphalidae ; host-plant selection ; growth ; size
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00194743
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  • 9
    Electronic Resource
    Electronic Resource
    Impaired host odor perception in hybrids between the sibling species Rhagoletis pomonella and R. mendax (1996)
    Springer
    Entomologia experimentalis et applicata 80 (1996), S. 163-165 
    Details
    ISSN: 1570-7458
    Keywords: olfaction ; EAG ; sensory physiology ; antennal sensitivity ; interspecies hybrids ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00194749
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  • 10
    Electronic Resource
    Electronic Resource
    Specificity of a Y-linked gene in the flea beetle Phyllotreta nemorum for defences in Barbarea vulgaris (1999)
    Springer
    Entomologia experimentalis et applicata 91 (1999), S. 359-368 
    Details
    ISSN: 1570-7458
    Keywords: Barbarea vulgaris ssp. arcuata ; Cruciferae ; Phyllotreta nemorum ; Chrysomelidae ; Alticinae ; flea beetle ; plant defence ; host plant range ; near-isogenic ; Y-linkage ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A Y-linked gene (R-gene) in the flea beetle Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) confer the ability of larvae to survive on types of the plant Barbarea vulgaris R.Br. (Brassicaceae) which are immune to attack by susceptible conspecifics. Two near-isogenic flea beetle lines were developed. The YE-line contained the Y-linked R-gene, and male larvae from this line survived on B. vulgaris. The ST-line did not contain the gene and did not survive on the plant. The YE-line had been developed through 8–9 generations of backcrosses (YE-males with ST-females) and the two lines were considered to be isogenic except for genes located on the Y-chromosome. A single copy of the Y-linked gene is sufficient to transfer a susceptible genotype (ST) into a resistant genotype (YE) which is able to utilize a plant that is immune to attack by specimens without R-genes. The Y-linked gene had no effects on survival on other plant species tested. The gene did not have any effect on developmental times and weights of adult beetles reared on other plants than B. vulgaris. Developmental times of larvae with the Y-linked gene were longer on B. vulgaris than on normal host plants, R. sativus and S. arvensis, but the adults obtained the same size on these plant species. No trade-offs of the Y-linked gene were discovered. The results suggest that the occurrence of the Y-linked gene is a derived trait which has enabled the flea beetle to expand its host plant range. The evolution of a host shift to B. vulgaris seems not to be favoured by the presence of this single gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003622512914
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  • 11
    Electronic Resource
    Electronic Resource
    Effects of bean and wheat α-amylase inhibitors on α-amylase activity and growth of stored product insect pests (1995)
    Springer
    Entomologia experimentalis et applicata 75 (1995), S. 237-244 
    Details
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02382258
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  • 12
    Electronic Resource
    Electronic Resource
    Do Maculinea rebeli caterpillars provide vestigial mutualistic benefits to ants when living as social parasites inside Myrmica ant nests? (2000)
    Springer
    Entomologia experimentalis et applicata 95 (2000), S. 97-103 
    Details
    ISSN: 1570-7458
    Keywords: butterfly ; Formicidae ; food ; growth ; mutualism ; myrmecophily ; parasitism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Caterpillars of the lycaenid butterfly Maculinea rebeli Hirschke (Lepidoptera: Lycaenidae) live for 11–23 months as social parasites in Myrmica (Hymenoptera: Formicidae) red ant nests, a trait that is believed to have evolved from mutualistic myrmecophilous ancestry. Although Maculinea rebeli caterpillars harm Myrmica larvae, they simultaneously produce copious secretions which the adult worker ants imbibe, perhaps representing a vestige of the ancestral mutualism. We report the results of laboratory experiments designed to test alternative hypotheses: (i) Maculinea rebeli caterpillars provide a beneficial source of sugar in return for being tended by Myrmicaworkers; (ii) Maculinea rebeli harms its host by stressing the workers by competing for available sugar. Comparisons were made of Myrmica worker fitness after 90–450 days under all possible combinations of three experimental treatments: ± M. rebeli caterpillars, ± sucrose and ± ant brood. Caterpillars always reduced the survival of both ant workers and their larvae, even when sugar was not provided, suggesting that M. rebeli is wholly parasitic on all stages in its host colony. The results also confirmed the importance of sucrose in the diet of Myrmica, and showed that M. rebeli caterpillars which eat ant brood to supplement their normal trophallactic feeding by workers develop more quickly - but have the same survival and pupal weights – as caterpillars that are fed solely by worker ants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003950318095
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  • 13
    Electronic Resource
    Electronic Resource
    Emergence and Maintenance of Sex among Diploid Organisms Aided by Assortative Mating (2000)
    Springer
    Acta biotheoretica 48 (2000), S. 137-147 
    Details
    ISSN: 1572-8358
    Keywords: Sex ; sexual selection ; mate selection ; evolution ; ploidy ; assortative mating ; recombination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Using computer simulations I studied the simultaneous effect of variable environments, mutation rates, ploidy, number of loci subject to evolution and random and assortative mating on various reproductive systems. The simulations showed that mutants for sex and recombination are evolutionarily stable, displacing alleles for monosexuality in diploid populations mating assortatively under variable selection pressure. Assortative mating reduced excessive allelic variance induced by recombination and sex, especially among diploids. Results suggest a novel adaptive value for sex and recombination. They show that the adaptive value of diploidy and that of the segregation of sexes is different to that of sex and recombination. The results suggest that the emergence of sex had to be preceded by the emergence of diploid monosexual organisms and provide an explanation for the emergence and maintenance of sex among diploids and for the scarcity of sex among haploid organisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1002765101959
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  • 14
    Electronic Resource
    Electronic Resource
    Respective Role of the Axialand Appendicular Systems in Relation to the Transition to Limblessness (1998)
    Springer
    Acta biotheoretica 46 (1998), S. 141-156 
    Details
    ISSN: 1572-8358
    Keywords: locomotion ; Squamata ; lizards ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In lower quadrupedal vertebrates locomotor efficiency seems to result from the associate movements of the axial and appendicular systems, which are totally independent in structure and embryological origin. The curvature of the trunk, produced by a standing wave, magnifies the propulsive action of the limbs. In intermediate forms, the association of an elongate trunk with limbs reduced in size brings about functional consequences which may be noticeably diverse according to the degree of trunk elongation and limb reduction. According to environmental constraints, animals search for better locomotor efficiency, which implies the maintenance or breakage of this association of both locomotor systems. In some cases, limb action on the ground is added to the axial wave action through a perfect mutual adjustment of rhythmic activity, until mechanical inefficiency of the limbs is reached by possible loss of contact with the ground. In other cases, the limbs dragged on the ground during the stance phase act against the axial action or, on the contrary, are inhibited by the axial system. A review of available data tries to contribute to an understanding of the respective roles of both systems in the transition to limblessness.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1001129920394
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  • 15
    Electronic Resource
    Electronic Resource
    Effects of temperature, multiple allelochemicals and larval age on the performance of a specialist caterpillar (1996)
    Springer
    Entomologia experimentalis et applicata 79 (1996), S. 335-344 
    Details
    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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    URL: http://dx.doi.org/10.1007/BF00186292
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    Chemosensory basis of feeding and oviposition behaviour in herbivorous insects: a glance at the periphery (1996)
    Springer
    Entomologia experimentalis et applicata 80 (1996), S. 7-13 
    Details
    ISSN: 1570-7458
    Keywords: host-plant selection ; sensory physiology ; neural coding ; deterrents ; peripheral interactions ; receptor sites ; genetics of insects ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Recent advances in our understanding of the relationship between chemosensory and behavioural responses to phytochemicals come from a number of studies on ovipositional and food selection behaviour of flies, butterflies, moths and beetles. Establishing input-output relationships has provided insight into the way in which the activity of chemoreceptors is translated into host-plant selection behaviour. This was achieved for both the qualitative contrast acceptance/rejection and for quantifiable preference hierarchies. By now it is clear that the subtlety of coding the complex phytochemical profiles offered by potential host plants relies on across-fibre patterns or ensemblefiring of taste neurons. Progress along these lines depends on unravelling processing pathways in the central nervous system, still a largely unexplored area in herbivorous insects. Increased interest can be noted for the mechanisms operating during the most peripheral events of chemoreception: the interaction of phytochemical and chemoreceptor, determining the specificity of recognition. Evidence for ‘peripheral integration’ has accumulated. Deterrent receptors have an especially puzzling nature. Although such cells respond to a wide array of structurally diverse secondary plant metabolites, their sensitivity profile differs between closely related species. To what extent membrane-bound receptor molecules are involved and what degree of specificity is conferred by these, is largely unknown. Sensitivity to a certain group or class of compounds is determined by single genes in several cases. This allows for a scenario in which single gene mutations affect stimulus-receptor interactions, which might concurrently affect host-plant selection behaviour.
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    URL: http://dx.doi.org/10.1007/BF00194713
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    Effects of the ecdysteroid agonists RH 5849 an RH 5992, alone and in combination with a juvenile hormone analogue, pyriproxyfen, on larvae ofSpodoptera exigua (1994)
    Springer
    Entomologia experimentalis et applicata 72 (1994), S. 115-123 
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    ISSN: 1570-7458
    Keywords: ecdysteroid agonists ; juvenile hormone analogue ; Spodoptera exigua ; growth ; moulting ; metamorphosis ; imaginal discs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Biological activity assays with RH 5849 and RH 5992 indicated that both compounds affected growth and development of last-instar larvae ofSpodoptera exigua (Hübner) (Lepidoptera: Noctuidae) in a dose-dependent manner. Within the first 24 h after treatment by continuously offering leaves dipped in a water solution of ≥50 mg/l RH 5849 and ≥0.5 mg/l RH 5992, symptoms of a prematurely induced larval moult and head capsule apolysis were visible. Intoxicated larvae died shortly afterwards, showing signs of unsuccessful ecdysis. LC50-values of RH 5849 and RH 5992 for fifth-instarS. exigua larvae were 110 and 2.5 mg/l, respectively. Pyriproxyfen alone affected the larval stage and disturbed normal metamorphosis. One supernumerary larval instar occurred occasionally. LC50-value for pyriproxyfen was 1.7 mg/l. Larvae simultaneously treated with RH 5849 or RH 5992 and pyriproxyfen, continued to grow until they attained a size and weight about 2–3 times that of the controls. This growth was accompanied by at least one and sometimes two supernumerary moults. Concerning thein vivo imaginal wing disc growth and development, only in larvae treated with 10 and 50 mg/l RH 5849 or 0.5 mg/l RH 5992, tracheole migration was observed earlier than in the controls. When applying 300 mg/l RH 5849 or 3–7 mg/l RH 5992, the discs remained small and no signs of tracheole migration were observed. In larvae simultaneously treated with RH 5849 or RH 5992 and pyriproxyfen, tracheole migration was not prematurely induced and a pupal cuticle was produced in the discs of larvae, undergoing a supernumerary moult. No clear signs of evagination were observed.
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    URL: http://dx.doi.org/10.1007/BF02383546
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    Insect-plant relations: overview from the symposium (1996)
    Springer
    Entomologia experimentalis et applicata 80 (1996), S. 320-324 
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    ISSN: 1570-7458
    Keywords: multitrophic interactions ; phylogeny ; evolution ; fitness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00194783
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    Effects of natural and synthetic neuroactive substances on the growth and feeding of cabbage looper, Trichoplusia ni (1996)
    Springer
    Entomologia experimentalis et applicata 80 (1996), S. 443-451 
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    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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    URL: http://dx.doi.org/10.1007/BF00343467
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    The folliculostatins of two dipteran insect species, their relation to matrix proteins and prospects for practical applications (1995)
    Springer
    Entomologia experimentalis et applicata 77 (1995), S. 1-9 
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    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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    URL: http://dx.doi.org/10.1007/BF02383011
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    Multitrophic effects of herbivore-induced plant volatiles in an evolutionary context (2000)
    Springer
    Entomologia experimentalis et applicata 97 (2000), S. 237-249 
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    ISSN: 1570-7458
    Keywords: herbivores ; predators ; parasitoids ; mutualism ; induced defence ; behaviour ; ecology ; evolution ; sensory physiology ; plant fitness ; pathogens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Herbivorous and carnivorous arthropods use plant volatiles when foraging for food. In response to herbivory, plants emit a blend that may be quantitatively and qualitatively different from the blend emitted when intact. This induced volatile blend alters the interactions of the plant with its environment. We review recent developments regarding the induction mechanism as well as the ecological consequences in a multitrophic and evolutionary context. It has been well established that carnivores (predators and parasitoids) are attracted by the volatiles induced by their herbivorous victims. This concerns an active plant response. In the case of attraction of predators, this is likely to result in a fitness benefit to the plant, because through consumption a predator removes the herbivores from the plant. However, the benefit to the plant is less clear when parasitoids are attracted, because parasitisation does usually not result in an instantaneous or in a complete termination of consumption by the herbivore. Recently, empirical evidence has been obtained that shows that the plant's response can increase plant fitness, in terms of seed production, due to a reduced consumption rate of parasitized herbivores. However, apart from a benefit from attracting carnivores, the induced volatiles can have a serious cost because there is an increasing number of studies that show that herbivores can be attracted. However, this does not necessarily result in settlement of the herbivores on the emitting plant. The presence of cues from herbivores and/or carnivores that indicate that the plant is a competitor- and/or enemy-dense space, may lead to an avoidance response. Thus, the benefit of emission of induced volatiles is likely to depend on the prevailing faunal composition. Whether plants can adjust their response and influence the emission of the induced volatiles, taking the prevalent environmental conditions into account, is an interesting question that needs to be addressed. The induced volatiles may also affect interactions of the emitting plant with its neighbours, e.g., through altered competitive ability or by the neighbour exploiting the emitted information. Major questions to be addressed in this research field comprise mechanistic aspects, such as the identification of the minimally effective blend of volatiles that explains the attraction of carnivores to herbivore-infested plants, and evolutionary aspects such as the fitness consequences of induced volatiles. The elucidation of mechanistic aspects is important for addressing ecological and evolutionary questions. For instance, an important tool to address ecological and evolutionary aspects would be to have plant pairs that differ in only a single trait. Such plants are likely to become available in the near future as a result of mechanistic studies on signal-transduction pathways and an increased interest in molecular genetics.
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    URL: http://dx.doi.org/10.1023/A:1004111624780
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    Specialist deterrent chemoreceptors enable Pieris caterpillars to discriminate between chemically different deterrents (1999)
    Springer
    Entomologia experimentalis et applicata 91 (1999), S. 29-35 
    Details
    ISSN: 1570-7458
    Keywords: chemoreception ; deterrents ; Pieris ; Brassicaceae ; cardenolides ; host-plant selection ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Pieris butterflies (Lepidoptera: Pieridae) are specialist herbivores of cruciferous plants. They exploit glucosinolates, secondary plant metabolites chemotaxonomically characteristic for this plant family, as token stimuli. In addition to particular glucosinolates, some genera of the Cruciferae contain cardenolides, steroidal allelochemicals that act as potent feeding and oviposition deterrents to several Pieris species. We investigated the sensory mechanisms by which these compounds are perceived in larvae. Pieris caterpillars and many other lepidopterous species are endowed with so-called generalist deterrent receptors, that respond to a broad spectrum of secondary plant substances. In Pieris caterpillars we found a second type of deterrent chemoreceptor in maxillary styloconic taste sensilla. This neuron is very sensitive to cardenolides (threshold 0.1–0.3 μM). The generalist deterrent receptor also responds to these substances but its threshold lies at 50–100× higher concentrations. In behavioural preference experiments Pieris brassicae L. caterpillars preferred cardenolide-treated cabbage leaf discs when confronted with a choice between them and a deterrent substance that does not occur in the Brassicaceae. The cardenolides acted as potent deterrents when offered against untreated cabbage leaf discs. This demonstrates that the balance of activity elicited in the two types of deterrent chemoreceptors determines the behavioural decision.
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    URL: http://dx.doi.org/10.1023/A:1003645222599
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    Feedback selection and the evolution of modifiers (1981)
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    Acta biotheoretica 30 (1981), S. 79-102 
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    ISSN: 1572-8358
    Keywords: evolution ; modifier theory ; dominance evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The problem of modifier evolution was examined with regard to the idea that modifier evolution can be considered as a result of selection for adaptation speed in populations far from equilibrium. This kind of selection was called ‘feedback selection’ in order to emphasize the difference to theories which consider modifier evolution near the equilibrium. The basic principles of this kind of selection are derived for asexual populations and the problem of dominance is discussed in the light of this concept. In general the results support the view, that the genetic properties of a character are selected along with the character itself.
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    URL: http://dx.doi.org/10.1007/BF00047674
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    Creativity in biology and in the human mind (Manifestation of Concepts) (1985)
    Springer
    Acta biotheoretica 34 (1985), S. 3-51 
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    ISSN: 1572-8358
    Keywords: anthropic principle ; creativity ; evolution ; insight ; manifestation ; mental creativity ; organismal creativity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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    URL: http://dx.doi.org/10.1007/BF00418105
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    On the Adaptive Value of Some Mate Selection Strategies (1999)
    Springer
    Acta biotheoretica 47 (1999), S. 29-40 
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    ISSN: 1572-8358
    Keywords: Sexual selection ; mate selection ; gamete selection ; evolution ; ploidy ; asssortative mating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Results of an agent-based computer simulation of the evolution of diploid sexual organisms showed that several mate selection strategies confer much higher average fitness to the simulated populations, and higher evolutionary stability to the alleles coding for these strategies, than random mating. Strategies which select for 'good genes' were very successful, and so were strategies based on assortative mating. The results support the hypothesis that mating is not likely to be random in nature and that the most successful mate selection strategies are those based on assortative mating or on advantageous genes.
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    URL: http://dx.doi.org/10.1023/A:1002022126388
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    Influence of larval dietary supply on the food consumption, food utilization efficiency, growth and development of the lacewingChrysoperla carnea (1993)
    Springer
    Entomologia experimentalis et applicata 67 (1993), S. 1-7 
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    ISSN: 1570-7458
    Keywords: Chrysoperla carnea ; food consumption ; growth ; development ; efficiency of food utilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Larvae of the common green lacewing,Chrysoperla carnea (Stephens)(Neuroptera: Chrysopidae), were fed either an optimal or a suboptimal number of eggs of the mothAnagasta kuehniella (Zeller) in the first and/or second larval instar, or in all three larval instars. Parameters for the duration, growth, and the efficiency of conversion of ingested food to body substance (ECI) of each instar were established for seven different dietary regimes. Larvae that had a suboptimal food supply in the first instar had a significantly longer developmental time, gained significantly less weight, and had a slightly lower ECI in that instar larvae. Suboptimally-fed second less, but remained only slightly longer in that instar and had a similar ECI to optimally-fed second instar larvae. The developmental time of suboptimally-fed third instar larvae was similar to that of optimally-fed larvae of that stage. Whereas the growth of the former was significantly less than that of larvae optimally fed in that instar, the ECI of the former was significantly higher. Despite the relatively smaller size of larvae fed suboptimally in the first and/or second instar, when such larvae were subsequently supplied with an overabundance of prey eggs, they consumed approximately the same number of eggs during the remainder of their larval life as did larvae whose food supply had not been restricted previously. When larvae were allowed to consume different numbers of eggs in their third instar, their gain in weight and therefore the weights attained by the resulting adults (based on the weights of 3-day-old cocoons) had a highly significant positive correlation with the number of eggs consumed in this instar.
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    URL: http://dx.doi.org/10.1007/BF02382710
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    Gravimetricvs. respirometric determination of metabolic efficiency in caterpillars ofPieris brassicae (1993)
    Springer
    Entomologia experimentalis et applicata 67 (1993), S. 135-142 
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    ISSN: 1570-7458
    Keywords: nutrition ; utilization ; efficiency ; growth ; metabolism ; energy ; respirometry ; Pieris
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Conventional gravimetry and a combination of gravimetry and respirometry were compared for their precision in measuring respiration and metabolic efficiency of growth of final stadiumPieris brassicae L. (Pieridae, Lepidoptera) caterpillars. This was done both for caterpillars feeding on an artificial diet and for caterpillars feeding on excised leaf material of a host plant,Brassica oleracea L. Gravimetry produced significantly greater variation in the total amount of matter respired and the metabolic efficiency than indirect calorimetry for caterpillars feeding on plant material, while the two methods gave similar results for the caterpillars reared on a meridic artificial diet. Respirometry (indirect calorimetry) revealed that caterpillars feeding on the artificial diet were growing with a higher metabolic efficiency than caterpillars feeding on the host plant. This difference was not revealed by conventional gravimetry. It is argued that metabolic efficiencies as derived from gravimetric budget calculations are subject to a number of random errors that distort precise determination of metabolic efficiencies in studies involving plant food.
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    URL: http://dx.doi.org/10.1007/BF02386518
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    Variation between strains of the flour beetle Tribolium castaneum in relative performance on five flours (1991)
    Springer
    Entomologia experimentalis et applicata 60 (1991), S. 173-182 
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    ISSN: 1570-7458
    Keywords: Genetics ; evolution ; host adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract When populations are exposed to different environments, evolutionary processes can lead either to genetically differentiated strains or to the appearance of increased generalism at the individual level. For evolution to occur, genetic variability in performance in different environments is required. Here, intraspecific genetic variation across environments was estimated in the flour beetle Tribolium castaneum (Herbst) by comparing the responses of two strains of T. castaneum to different flour types. Replicated groups from each strain were allowed to develop on either the standard whole wheat medium or on one of four novel flours (wheat, rice, corn and oat). In several of the novel flours, clear differences in mean development time or population size of one or both strains were seen relative to performance in the standard medium. Moreover, the strains differed significantly in their phenotypic responses to the flours. One strain did particularly poorly on oat flour. Reduced oviposition, reduced larval survivorship and increased larval cannibalism were examined as possible causes of the low productivity on oat flour. These three factors accounted for about 70% of the reduction in population size when this strain oviposited and developed in oat flour. The difference between these two outbred strains in response to these five flours suggests that genetic variation in resource use is present within T. castaneum and may also be present within strains and natural populations in grain storage facilities. Such variation would permit an evolutionary response to selection in multiple environments (flours). This process has agricultural implications when several types of grain are stored in a single location because it could eventually lead to the evolution of highly generalized populations of T. castaneum, an important pest of stored products.
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    Azadirachtin inhibits secretion of trypsin in midgut of Manduca sexta caterpillars: reduced growth due to impaired protein digestion (1992)
    Springer
    Entomologia experimentalis et applicata 63 (1992), S. 47-54 
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    ISSN: 1570-7458
    Keywords: Azadirachtin ; Manduca sexta ; growth ; feeding efficiency ; nitrogen utilisation ; proteinase ; trypsin ; allelochemicals ; antifeedant ; herbivory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract When given by injection to tobacco hornworm caterpillars, Manduca sexta, the allelochemical azadirachtin inhibits growth without reducing food intake. The growth reducing effect of azadirachtin is therefore in this case independent of the compound's well-known antifeedant effect. The cause of this reduced rate of growth is an increase in the costs associated with growth. These increased costs are largely a consequence of a decrease in the efficiency of utilisation of dietary nitrogen. This is associated with a drastic reduction in the activity of midgut trypsin. Azadirachtin has no effect on the activity of trypsin in vitro. Thus azadirachtin directly or indirectly inhibits the production of trypsin by the enzyme-secreting cells of the midgut wall; it is suggested that this is the cause of the increased costs and reduced rate of growth. The interesting parallel between this plant defence strategy and that of direct inhibition of herbivore proteinases by allelochemical proteinase inhibitors is discussed.
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    Antifeedant activity of bisabolangelone and its analogs against larvae of Pieris brassicae (1989)
    Springer
    Entomologia experimentalis et applicata 53 (1989), S. 257-265 
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    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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    Genetics of the ability of Phyllotreta nemorum larvae to survive in an atypical host plant, Barbarea vulgaris ssp. arcuata (1997)
    Springer
    Entomologia experimentalis et applicata 82 (1997), S. 37-44 
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    ISSN: 1570-7458
    Keywords: Barbarea vulgaris ; Cruciferae ; Phyllotreta nemorum ; Chrysomelidae ; Alticinae ; flea beetle ; plant defence ; genetics ; sex-linkage ; X- and Y-chromosome ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A polymorphism in host plant exploitation has been discovered in the flea beetle, Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) where one resistant population is able to use Barbarea vulgaris R.Br. ssp. arcuata (Opiz.) Simkovics (Brassicaceae) as a host plant while a susceptible population is not. Crosses (F1, F2, and backcrosses) between the two flea beetle populations were made, and survival of the progeny on B. v. ssp. arcuata was measured. The ability of P. nemorum larvae to survive in this plant species depended on the presence of major, dominant genes (R-genes). The two most abundant R-genes in the resistant flea beetle population were X- and Y-linked, respectively. The use of B. v. ssp. arcuata as a natural host plant by the resistant population of P. nemorum seems to be an extension of the host plant range of the species. The role of sex-linked genes in the evolution of host range is discussed.
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    URL: http://dx.doi.org/10.1023/A:1002938912809
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    Variation in defences of the plant Barbarea vulgaris and in counteradaptations by the flea beetle Phyllotreta nemorum (1997)
    Springer
    Entomologia experimentalis et applicata 82 (1997), S. 25-35 
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    ISSN: 1570-7458
    Keywords: Barbarea vulgaris ; Cruciferae ; Phyllotreta nemorum ; Chrysomelidae ; Alticinae ; flea beetle ; plant defence ; resistance ; host plant ; variation ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Several sorts of variation in the interaction between the insect, Phyllotreta nemorum L. (Coleoptera:Chrysomelidae:Alticinae), and the plant, Barbarea vulgaris R.Br. (Brassicaceae), have been discovered: 1) genetic differences in the levels of defences in the plant, 2) genetic differences in the ability of insects to cope with the plant defences, 3) seasonal variation in levels of defences in the plant, and 4) differences between leaf types in levels of defences. Two plant accessions were suitable for larval development throughout the season while the remaining nine accessions were more or less unsuitable for larvae from the ‘susceptible’ T-population at least at certain times of the year. All accessions were suitable for the ‘resistant’ E-population throughout the year. There was a seasonal variation in levels of defences in some accessions which were unsuitable for the T-population during the summer period when beetles were present, but not during autumn and spring when the beetle were hibernating. Upper (younger) cauline leaves of these accessions had higher levels of defences than lower (older) cauline leaves. The resistant E-population used B. vulgaris as a natural host plant while the susceptible T-population did not. The use of B. vulgaris as a natural host plant by the E-population of P. nemorum seems to be an extension of the host plant range of the species. Variation in plant defences may have facilitated the switch in host plant use by the resistant flea beetle population.
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    The making of a pest: recruitment of Meligethes aeneus onto oilseed Brassicas (2000)
    Springer
    Entomologia experimentalis et applicata 95 (2000), S. 141-149 
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    ISSN: 1570-7458
    Keywords: ecology ; reproductive success ; fecundity ; intraspecific competition ; evolution ; pest outbreaks ; pest control ; chemical control ; economic threshold ; oilseed rape ; turnip rape
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Populations of the rapeseed pollen beetle Meligethes aeneus F. (Col., Nitidulidae) from areas with 0–16 years of history of intensive rapeseed growing were compared for key ecological characters. During the first 16 years of rapeseed cultivation the reproductive success of M. aeneus increased 200–300% over that of the beetles living on the natural host plants, cruciferous weeds. The increase was linear over time and statistically highly significant, and it did not appear to be related to food quality or to the size of the beetles. During the same period the tolerance to intraspecific competition decreased, possibly due to the relative absence of such competition on the new crop. Furthermore, the optimum population density for M. aeneus to maximize the size of its next generation on summer turnip rape was determined to be 0.5–1.0 beetles/plant, which is slightly below the economic threshold for chemical control (1 beetle/plant). Therefore the practical protection of the rapeseed yield also ensures the highest possible pest population size for the next year. These mechanisms may in part explain the particular noxiousness of the species as a pest all over Europe. In general these data show that after the introduction of a new crop plant into a region, significant changes during the recruitment process in a pestiferous insect may take place, contributing to the future pest status of the insect. It is suggested that such genetic and ecological changes in insects may be a more common mechanism than previously thought in initiating and sustaining pest outbreaks, and that conventional pest management methods may enhance that effect.
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    Copulatory Courtship in Drosophila: Behavior and Songs of D. birchii and D. serrata (2000)
    Springer
    Journal of insect behavior 13 (2000), S. 71-86 
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    ISSN: 1572-8889
    Keywords: copulatory courtship ; behavioral interactions ; songs ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract D. birchii and D. serrata, two endemic Australian Drosophila species, have a copulatory courtship. The males of these species begin to court the female after mounting her and often go on with the courtship after the copulation is over. In the present paper we have described behavioral interactions between the male and the female and analyzed acoustic signals produced by the flies during courtship. Species differences were more pronounced in female than in male behavior. Variation within the species was obvious in the relative proportions of time the flies spent in different behaviors. Even though courtship took place nearly solely during copulation, some remains of precopulatory courtship were observed in both species. It is suggested that copulatory courtship exhibited by D. birchii and D. serrata flies is a derived rather than a primitive character.
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    Cockroach mating behaviors, sex pheromones, and abdominal glands (Dictyoptera: Blaberidae) (1993)
    Springer
    Journal of insect behavior 6 (1993), S. 715-735 
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    ISSN: 1572-8889
    Keywords: Aphrodisiac ; cockroach ; evolution ; mating behavior ; sex pheromone ; sternal glands ; tergal glands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two chemical signals are essential in all cockroach sexual behavioral sequences: the sex pheromone released by one partner, generally the female (for long distance attraction), and an aphrodisiac sex pheromone produced exclusively by male tergal glands (for female mounting and tergal contact or “feeding” behavior). Unlike the other cockroach groups, the males of the Oxyhaloinae species produce both chemical signals: the pheromone and the aphrodisiac. The occurrence of three patterns of mating behavior (A, B, and C), the production of male sex pheromones, and the existence in the male of developed sternal and tergal glands in seven related Oxyhaloinae species, make these cockroaches a useful model for studying the evolution of mating behavior patterns. The various types of mating behavior were not classified in the previous studies by Roth and Barth. In this report, they have been named type A (female in upper position), B (male in upper position), and C (male and female end to end). In type A mating, the male tergal glands, which are licked by the females, are well developed, whereas in types B and C, there is no licking of the male's tergal secretion by the females and the tergal glands are much less developed; the aphrodisiacs secreted by the tergal glands may no longer act in this case through contact chemoreception, but through an olfactory process involving volatile components. One common sex pheromone component seems to be acetoin. I suggest that the mating behavior tends from A toward B and C during the evolutionary process with a concomitant regression of the tergal glands and changes in the aphrodisiac emission levels. The mating behavioral sequences of cockroaches (Dictyoptera) and crickets (Orthoptera) show a striking degree of similarity and are probably examples of convergent evolution.
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    Egg attendance and brooding by males of the giant water bugLethocerus medius (Guerin) in the field (Heteroptera: Belostomatidae) (1993)
    Springer
    Journal of insect behavior 6 (1993), S. 93-106 
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    ISSN: 1572-8889
    Keywords: Belostomatidae ; giant water bugs ; paternal care ; eggs ; reproduction ; behavior ; brooding ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Males of the giant water bug Lethocerus medius(Guerin) typify their monobasic subfamily, the Lethocerinae, in that they do not brood eggs attached to their backs as do males of all members of the subfamily Belostomatinae. Exclusive male parental investment as expressed in the Belostomatinae is extremely rare behavior among animals, and evolution of the trait is obscure. Lethocerus mediusmales apparently remain with their mates through oviposition and are consistently found in attendance of eggs after the female has departed. This behavior may enhance paternity assurance at no cost in opportunity for polygyny. Two double clutches of eggs were found, from which we infer the potential for polygynous matings and shared parental investment. Male L. mediusbrood attended egg clutches above the surface of the water, where they may moisten them, shade them, and defend them against predation. Egg attendance/brooding by L. mediusand other Lethocerusspecies may represent a plesiomorphic state from which paternal back- brooding evolved in the Belostomatinae.
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    The origin and evolution of social life in the Stenogastrinae (Hymenoptera, Vespidae) (1989)
    Springer
    Journal of insect behavior 2 (1989), S. 649-661 
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    ISSN: 1572-8889
    Keywords: sociality ; evolution ; Vespidae ; Stenogastrinae ; brood rearing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Stenogastrinae are a subfamily of the Vespidae. The main difference between these and other social wasps (Polistinae and Vespinae) is a jelly-like substance that the Stenogastrinae secrete from the Dufour 's gland and use in many functions of their biology. It is suggested that this substance greatly contributed to the evolution of social life in these wasps by making it possible to nourish the brood with liquid food and store it in the nest, thus favoring also the evolution of the behavioral mechanisms which facilitated interactions between adults. Social organization of the colonies may have been kept at a low level through a basic system of continuous temporary helper replacement, while the evolution of large colonies was restrained, as well as by the poor quality of construction material, low egg-laying capacity and limited production of abdominal substance, imperfect social regulatory mechanisms, and the absence of defensive mechanisms of the colonies against large predators.
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    The influence of OH groups on the growth of rhodium on alumina: a model study (2000)
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    Catalysis letters 68 (2000), S. 19-24 
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    ISSN: 1572-879X
    Keywords: aluminum oxide ; hydroxyl groups ; rhodium ; growth ; scanning tunneling microscopy ; infrared spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract In order to investigate how the presence of surface hydroxyl groups on oxide surfaces affects the interaction with the supported metal, we have modified a well-ordered alumina film on NiAl(110) by Al deposition and subsequent exposure to water. This procedure yields a hydroxylated alumina surface as revealed by infrared and high-resolution electron energy loss spectroscopy. By means of scanning tunneling microscopy, we have studied the growth of rhodium on the modified film at 300 K. Clear differences in the particle distribution and density are observed in comparison to the clean substrate. While, in the latter case, decoration of domain boundaries as typical defects of the oxide film governs the growth mode, a more isotropic island distribution and a drastically increased particle density is found on the hydroxylated surface. From infrared data, it can be deduced that the growth is connected with the consumption of the hydroxyl groups due to the interaction between the metal deposit and the hydroxylated areas. This finding is in line with photoemission results published earlier.
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    Growth and long-run stability (1987)
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    Acta applicandae mathematicae 9 (1987), S. 219-237 
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    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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    Evolution of Ti–Sn-rutile-supported V2O5–WO3 catalyst during its use in nitric oxide reduction by ammonia (2000)
    Springer
    Topics in catalysis 11-12 (2000), S. 131-138 
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    ISSN: 1572-9028
    Keywords: rutile supported V2O5–WO3 catalyst ; evolution ; NO reduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This paper concerns the relation between surface structure of crystalline vanadia-like active species on vanadia–tungsta catalyst and their activity in the selective reduction of NO by ammonia to nitrogen. The investigations were performed for Ti–Sn-rutile-supported isopropoxy-derived catalyst. The SCR activity and surface species structure were determined for the freshly prepared catalyst, for the catalyst previously used in NO reduction by ammonia (320 ppm NO, 335 ppm NH3 and 2.35 vol% O2) at 573 K as well as for the catalyst previously annealed at 573 K in helium stream containing 2.35 vol% O2. The crystalline islands, exposing main V2O5 surface, with some tungsten atoms substituted for V-ones, were found, with XPS and FT Raman spectroscopy, to be present at the surface of the freshly prepared catalyst. A profound evolution of the active species during the catalyst use at 573 K was observed. Dissociative water adsorption on V5+OW6+ sites is discussed as mainly responsible for the catalyst activity at 473 K and that on both V5+OW6+ and V4+OW6+ sites as determining the activity at 523 K.
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    An extremely cadmium-sensitive strain ofChlorella (1985)
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    Cellular and molecular life sciences 41 (1985), S. 1621-1621 
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    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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    Evolutionary and ecological implications of cardenolide sequestration in the monarch butterfly (1989)
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    Cellular and molecular life sciences 45 (1989), S. 284-295 
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    ISSN: 1420-9071
    Keywords: Annual cycle ; Asclepias ; cardenolide ; Danaidae ; Danaus plexippus ; defense ; ecological chemistry ; evolution ; herbivory ; host plant ; life history ; migration ; milkweed ; monarch butterfly ; overwintering ; predation ; repellent allomone ; sequestration ; storage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Monarch butterflies sequester cardenolides from their larval host plants in the milkweed genusAsclepias for use in defense against predation. Of 108Asclepias species in North America, monarchs are known to feed as larvae on 27. Research on 11 of these has shown that monarchs sequester cardenolides most effectively, to an asymptote of approximately 350 μg/0.1 g dry butterfly, from plants with intermediate cardenolide contents rather than from those with very high or very low cardenolide contents. SinceAsclepias host plant species are distributed widely in space and time across the continent, monarchs exploit them by migration between breeding and overwintering areas. After overwintering in central Mexico, spring migrants east of the Rocky Mountains exploit three predominantAsclepias species in the southern USA that have moderately high cardenolide contents. Monarchs sequester cardenolides very effectively from these species. First generation butterflies are thus well protected against predators and continue the migration north. Across the northern USA and southern Canada most summer breeding occurs on a fourthAsclepias species and in autumn most of these monarchs migrate back to Mexican overwintering sites. The ecological implications of this cycle of cardenolide sequestration for the evolution of monarch migration are discussed.
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    Cardiac design in lower vertebrates: what can phylogeny reveal about ontogeny? (1988)
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    Cellular and molecular life sciences 44 (1988), S. 919-930 
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    ISSN: 1420-9071
    Keywords: Heart ; circulation ; blood ; lower vertebrate ; embryology ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In very few instances can the cardiovascular systems of adult ‘lower’ vertebrates serve asdirect models for development in ‘higher’ vertebrates, primarily because numerous evolutionary specializations for preferential distribution of cardiac output between systemic tissues and gas exchange, organs occur in the highly derived circulation of most extant lower vertebrates. Yet, the extensive literature on the cardiovascular anatomy and physiology of aquatic and air breathing fishes, amphibians and reptiles offers important conceptual insights into both patterns and mechanisms of development in birds and mammals. The primary contribution of such studies to the student of developing bird and mammal circulations is the clear demonstration that surprisingly complex hemodynamic function can develop from supposedly ‘simple’ cardiovascular systems typified by incompletely divided heart chambers. Thus, the hemodynamics of embryonic bird and mammal circulations should be determined by measurement, rather than inferred from structure.
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    Ancient DNA: An introduction (1994)
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    Cellular and molecular life sciences 50 (1994), S. 521-523 
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    ISSN: 1420-9071
    Keywords: Ancient DNA ; evolution ; conservation ; biology ; anthropology ; plant biology ; PCR (polymerase chain reaction)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1007/BF01921719
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    Butterflies and ants: The communicative domain (1996)
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    Cellular and molecular life sciences 52 (1996), S. 14-24 
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    ISSN: 1420-9071
    Keywords: Lycaenidae ; Formicidae ; symbiosis ; mutualism ; parasitism ; communication ; ecology ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Associations with ants, termed myrmecophily, are widespread in the butterfly family Lycaenidae and range from mere co-existence to more or less specific mutualistic or even parasitic interactions. Secretions of specialized epidermal glands are crucial for mediating the interactions. Transfer of nutrients (carbohydrates, amino acids) from butterfly larvae to ants plays a major role, but manipulative communication with the help of odour signals is also involved. By means of myrmecophily, lycaenid butterflies largely escape ant predation, and certain species gain protection through attendant ants or achieve developmental benefits from ant-attendance. Benefits to the ants range from minimal to substantial food rewards. While most lycaenid species maintain facultative relationships with a variety of ant genera, highly specific and obligatory associations have convergently evolved in a number of butterfly lineages. As a corollary, communication systems are largely unspecific in the former, but may be highly specialized in the latter. The sophisticated communication between obligate myrmecophiles and their host ants is tightly connected with the evolutionary rise of specialized life-cycles and thus is a source of augmenting diversity within the butterflies.
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    A novel mechanism for jumping in the indian antHarpegnathos saltator (Jerdon) (Formicidae, Ponerinae) (1994)
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    Cellular and molecular life sciences 50 (1994), S. 63-71 
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    ISSN: 1420-9071
    Keywords: Insect ; behaviour ; high-speed cinematography ; jumping ; electrophysiology ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The Indian antHarpegnathos saltator may be unique among insects in using its jumping capacity not only as an escape mechanism but also as a normal means of locomotion, and for catching its prey in flight. High-speed cinematography used to analyse the various phases of the jump suggests thatHarpegnathos employs a novel jumping mechanism to mediate these behaviours: namely the synchronous activation of its middle and hindlegs. Electrophysiological recordings from muscles or nerves in pairs of middle and hindlegs show remarkably synchronous activity during fictive jumping, supporting the synchronous activation hypothesis.Harpegnathos is not the only ant to jump, and a cladistic analysis suggests that jumping behaviour evolved independently three times during ant evolutionary history.
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    Systematics and evolution of holarctic Pierinae (Lepidoptera). An enzyme electrophoretic approach (1985)
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    Cellular and molecular life sciences 41 (1985), S. 24-29 
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    ISSN: 1420-9071
    Keywords: Pieridae ; Lepidoptera ; systematics ; evolution ; enzyme electrophoresis ; genetic differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Enzyme electrophoretic data show a remarkably high degree of genetic similarity within the European group ofnapi s.l. whereas genetic differences exist at several loci between the European and the North American taxa ofnapi s.l. It is concluded that the European taxa did not differentiate to the species level and form a phylogenetically young group. The North American taxa included in this study are specifically distinct from Europeannapi and separated much earlier. Within these North American taxamarginalis, oleracea andvirginiensis did undergo speciation. The data show a splitting of the genusPieris into three species groups, each genetically differentiated to the same level. The splitting ofPieris into two genera, as suggested by earlier investigators, is not supported here.
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    The evolution of sex and the role of sex in evolution (1985)
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    Cellular and molecular life sciences 41 (1985), S. 1231-1235 
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    ISSN: 1420-9071
    Keywords: Sex ; recombination ; evolution ; parasites ; the Tangled Bank ; the Red Queen ; sex-allocation ; sexual selection ; sex determination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
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    Two theories of sex and variation (1985)
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    Cellular and molecular life sciences 41 (1985), S. 1235-1245 
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    ISSN: 1420-9071
    Keywords: Sex ; evolution ; the Tangled Bank ; the Red Queen ; recombination experiments ; genotype × environment interactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
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    Growth and the average duration of larval life in the southern hemisphere lamprey,Geotria australis Gray (1986)
    Springer
    Cellular and molecular life sciences 42 (1986), S. 1170-1173 
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    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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    Misuses of biology in the context of the paranormal (1988)
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    Cellular and molecular life sciences 44 (1988), S. 297-303 
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    ISSN: 1420-9071
    Keywords: Biology ; creation science ; creationism ; evolution ; hundredth monkey phenomenon ; paranormal ; pseudoscience
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Public suspicion of science stems from science's challenging of perceptions and myths about reality, and a public fear of new technology. The result is a susceptibility to pseudoscience. In claiming that creation ‘science’ is as valid as evolution the creationists misquote scientists and seek to spread their own ‘scientific’ myths concerning a young age for the earth, an act of creation based on a particular literalist interpretation of the Christian Bible and a single worldwide flood. They use methods of debate and politics, rather than scientific research. A selection of their arguments is examined and the nature of the evidence for evolution is discussed. Problems with the creation ‘science’ model are noted. In the myth of the hundredth monkey phenomenon, original research is misquoted to denigrate scientific research and support sentimental ideas of paranormal events. The misuse of science is seen as damaging to society because it reduces the effective gathering and application of scientific information. However, pseudoscience provides a valuable guide to gaps in public scientific education.
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    Ontogenetic development and evolution of the worker caste in termites (1987)
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    Cellular and molecular life sciences 43 (1987), S. 851-860 
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    ISSN: 1420-9071
    Keywords: Social insects ; Isoptera ; caste differentiation ; reproductive biology ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The hemimetabolous termites have a very different caste system from social Hymenoptera in which only true imagoes participate in all social tasks. In termites, the imagoes are restricted to reproduction. The termite solidiers have no equivalent in other social insects. They are unique both in their post-embryonic development and their exclusively defensive function. At maturity they keep their molting gland and therefore should be considered as stabilized, differentiated immatures. They appeared monophyletically, early in the evolution of termites. The definition of the worker caste and the current theories explaining its evolution are reexamined after a critical reappraisal of data on post-embryonic development. On the basis of ontogenic, morphologic and functional criteria, we define termite workers as individuals diverging early and irreversibly from the imaginal development, with a morphology typical of their caste but largely of larval appearance, and taking part in most of the social tasks. Such a truly eusocial worker caste is observed in all advanced phyla: Termitidae, Hodotermitidae, andSchedorhinotermes (Rhinotermitidae), but apparently also in one morphologically primitive termite,Mastotermes darwiniensis. This distribution can only be explained by postulating a polyphyletic origin of the worker caste in termites. In all other primitive termites, most of the work is done by temporary helpers (late larvae and nymphs). In these societies, pseudergates are redefined as individuals separating late from the imaginal line, functioning as workers, but not constituting the main working force in the natural society. The particularity of the caste system in termites results from two fundamental peculiarities of their post-embryonic development: -A certain dissociation of molt, growth, and differentiation. -A relative independence in the ontogeny of their different organs.
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    Sex pheromone communication in the lepidoptera: New research progress (1989)
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    Cellular and molecular life sciences 45 (1989), S. 248-262 
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    ISSN: 1420-9071
    Keywords: Sex pheromone ; biosynthesis ; neurobiology ; sensory biology ; orientation behavior ; flight control ; anemotaxis ; genetics ; communication ; olfaction ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Significant progress has been made recently in research on lepidopterous sex pheromones. Advances in understanding the biochemical, neurobiological, and behavioral events that results in both successful and unsuccessful pheromone communication have allowed researchers to gain new insights into the genetic control and evolution of phermone systems.
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    URL: http://dx.doi.org/10.1007/BF01951811
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    Eucaryotic codes (1990)
    Springer
    Cellular and molecular life sciences 46 (1990), S. 1106-1117 
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    ISSN: 1420-9071
    Keywords: Genetic code ; eucaryotic cell ; evolution ; code ambiguity ; code universality ; convergence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This article is a review of the rules used by eucaryotic cells to translate a nuclear messenger RNA into a polypeptide chain. The recent observation that these rules are not identical in two species of a same phylum indicates that they have changed during the course of evolution. Possible scenarios for such changes are presented.
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    URL: http://dx.doi.org/10.1007/BF01936920
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    Biology of halophilic bacteria, Part II (1993)
    Springer
    Cellular and molecular life sciences 49 (1993), S. 1027-1036 
    Details
    ISSN: 1420-9071
    Keywords: Archaea (archaebacteria) ; extreme halophiles ; archaeol phospholipids ; archaeol glycolipids ; membrane function ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Archaebacteria (archaea) are comprised of three groups of prokaryotes: extreme halophiles, methanogens and thermoacidophiles (extreme thermophiles). Their membrane phospholipids and glycolipids are derived entirely from a saturated, isopranoid glycerol diether,sn-2,3-diphytanylglycerol (‘archaeol’) and/or its dimer, dibiphytanyldiglyceroltetraether (‘caldarchaeol’). In extreme halophiles, the major phospholipid is the archaeol analogue of phosphatidylglycerolmethylphosphate (PGP-Me); the glycolipids are sulfated and/or unsulfated glycosyl archaeols with diverse carbohydrate structure characteristic of taxons on the generic level. Biosynthesis of these archaeol-derived polar lipids occurs in a multienzyme, membrane-bound system that is absolutely dependent on high salt concentration (4 M). The highly complex biosynthetic pathways involve intermediates containing glycerol ether-linked C20-isoprenyl groups which are reduced to phytanyl groups to give the final saturated polar lipids. In methanogens, polar lipids are derived both from archaeol and caldarchaeol, and thermoacidophiles contain essentially only caldarchaeol-derived polar lipids. The function of these membrane polar lipids in maintaining the stability, fluidity and ionic properties of the cell membrane of extreme halophiles, as well as the evolutionary implications of the archaeol and caldarchaeol-derived structures will be discussed.
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    URL: http://dx.doi.org/10.1007/BF01929909
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    Presence of a partial urea cycle in the leech,Poecilobdella granulosa (1992)
    Springer
    Cellular and molecular life sciences 48 (1992), S. 729-731 
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    ISSN: 1420-9071
    Keywords: Urea cycle ; leech ; botryoidal tissue ; hirudineans ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Ornithine carbamoyltransferase (OCT) and arginase, but not arginine synthetase (AS), were detected in the body wall and gut tissues of the leech. The activities of these enzymes were not altered by starvation. The high activity of arginase in body wall is probably due to the association of the latter with botryoidal tissue. Hirudineans, which evolved from oligochaete ancestors, appear to have lost the citrulline-arginine segment of the urea cycle due to their ammonotelic mode of nitrogen excretion.
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    URL: http://dx.doi.org/10.1007/BF02124288
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    Genetic aspects of the hsp70 multigene family in vertebrates (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 987-1001 
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    ISSN: 1420-9071
    Keywords: Hsp70 ; evolution ; gene duplication ; gene homology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The family of genes encoding heat shock proteins of about 70 kDa (hsp70) in vertebrates is reviewed under genetic aspects. After a detailed description of the various hsp70 genes more general characteristics of the organization and evolution of the multigene family are discussed.
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    URL: http://dx.doi.org/10.1007/BF01923453
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    Chitin in the epidermal cuticle of a vertebrate (Paralipophrys trigloides, Blenniidae, Teleostei) (1993)
    Springer
    Cellular and molecular life sciences 49 (1993), S. 317-319 
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    ISSN: 1420-9071
    Keywords: Chitin ; cuticle ; evolution ; vertebrates ; bony fish ; Blenniidae ; Paralipophrys trigoides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Lectin binding, endo-chitinase binding and enzymatic degradation studies show that the epidermal cuticle of the bony fishParalipophrys trigloides (Blenniidae) is chitinous. This is the first evidence that a vertebrate species possesses a chitinous tissue. Recently aXenopus gene has been identified which has significant sequence similarity to the catalytic domain of yeast chitin synthase III, a chitin producing enzyme1,2. Taken together these two findings imply that chitin synthesis capability may be a basic vertebrate feature.
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    Genetic ecology: A new interdisciplinary science, fundamental for evolution, biodiversity and biosafety evaluations (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 429-437 
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    ISSN: 1420-9071
    Keywords: Genetics ; ecology ; DNA-transfer ; conjugation ; transformation ; transduction ; transposons ; dormant cells ; epilithon ; microbial colonisation ; symbiosis ; virus resistance ; biosafety ; release of genes ; insults to humanity ; evolution ; biodiversity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Genetic ecology is the extension of our modern knowledge in molecular genetics to studies of viability, gene expression and gene movements in natural environments like soils, aquifers and digestive tracts. In such milieux, the horizontal transfer of plasmid-borne genes between phylogenetically distant species has already been found to be much more frequent than had been expected from laboratory experience. For the study of exchanges involving chromosomally-located genes, more has to be learned about the behaviour of transposons in such environments. The results expected from studies in genetic ecology are relevant for considerations of evolution, biodiversity and biosafety. The role of this new field of research in restoring popular confidence in science and in its biotechnological applications is stressed.
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    URL: http://dx.doi.org/10.1007/BF01920741
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    Quantitative genetics of zooplankton life histories (1995)
    Springer
    Cellular and molecular life sciences 51 (1995), S. 454-464 
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    ISSN: 1420-9071
    Keywords: Quantitative genetics ; life history ; evolution ; cladocera ; heritability ; Daphnia ; zooplankton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Quantitative genetic techniques are powerful tools for use in understanding the microevolutionary process. Because of their size, lifespan, and ease of culture, many zooplankton species are ideal for quantitative genetic approaches. As model systems, studies of zooplankton life histories are becoming increasingly used for examination of the central paradigms of evolutionary theory. Two of the fundamental empirical questions that zooplankton quantitative genetics studies can answer are: 1) How much genetic variance exists in natural populations for life history traits? 2) What is the empirical evidence for trade-offs that permeate life history theory based on optimality approaches? A review of existing data onDaphnia indicates substantial genetic variance for body size, clutch size, and age at first reproduction. Average broad-sense heritabilities for these three characters across 19 populations of 6 species are 0.31, 0.31, and 0.34, respectively. Although there is some discrepancy between the two pertinent studies that were designed to decompose the total genetic variance into its additive and non-additive components, a crude average seems to suggest that approximately 60% of the total genetic variance has an additive basis. The existing data are somewhat inconsistent with respect to presence/absence of trade-offs (negative genetic correlations) among life history traits. A composite of the existing data seems to argue against the existence of strong trade-offs between offspring size and offspring number, between present and future reproduction, and between developmental rate and fecundity. However, there is some evidence for a shift toward more negative (less positive) covariances in more stressful environments (e.g., low food). Zooplankton will prove to be very useful in future study in several important areas of research, including the genetics and physiology of aging, the importance of genotype-environment interaction for life history traits, and the evolution of phenotypic plasticity.
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    URL: http://dx.doi.org/10.1007/BF02143198
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    The accessory gland proteins in maleDrosophila: structural, reproductive, and evolutionary aspects (1996)
    Springer
    Cellular and molecular life sciences 52 (1996), S. 503-510 
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    ISSN: 1420-9071
    Keywords: Drosophila ; accessory gland ; reproduction ; sexual behavior ; sperm displacement ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Recent results from biochemical and molecular genetic studies of the accessory gland proteins in maleDrosophila are reviewed. The most prominent feature is the species-specific variability. However, the analysis of the sex peptide inD. melanogaster shows that there is a strong homology in the molecular structure to the closely related sibling species, and that divergence increases with increasing phylogenetic distance. For this reason the sex peptide, after being transferred to the female genital tract during copulation, reduces receptivity and increases oviposition only in virgin females belonging to the same species group and subgroup. Even though studies were hitherto limited to a small number of the secretory components, it is evident that the accessory gland proteins play a key role in reproductive success of the fruit fly by changing female sexual behavior, supporting sperm transfer, storage and displacement. Thus, genes encoding the accessory gland proteins are apparently under strong evolutionary selection.
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    URL: http://dx.doi.org/10.1007/BF01969718
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    The nutritional ecology of larvae of Alsophila pometaria and Anisota senatoria feeding on early- and late-season oak foliage (1984)
    Springer
    Entomologia experimentalis et applicata 35 (1984), S. 105-114 
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    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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    URL: http://dx.doi.org/10.1007/BF00217527
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    Acyrthosiphon pisum performance in response to the sugar and amino acid composition of artificial diets, and its relation to lucerne varietal resistance (1988)
    Springer
    Entomologia experimentalis et applicata 48 (1988), S. 283-292 
    Details
    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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    Host specificity in phytophagous insects: selection pressure from generalist predators (1988)
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    Entomologia experimentalis et applicata 49 (1988), S. 131-140 
    Details
    ISSN: 1570-7458
    Keywords: evolution ; monophagy ; polyphagy ; host range ; Vespidae ; caterpillars ; predation ; Mischocyttarus flavitarsus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The narrow host range of insect herbivores is noted, and some of the reasons why specificity has evolved are reviewed. Works indicating the need for new approaches are pointed out including the possibility that generalist predators provide a suitable pressure. Experiments to test the hypothesis that generalists are more vulnerable than specialists to predators are described. They involved a vespid wasp and over thirty species pairs of caterpillars, matched for size and density. Overall, generalists were taken more readily than specialists: some but not all reasons could be detected. The results are discussed in ecological and evolutionary terms.
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    URL: http://dx.doi.org/10.1007/BF00188246
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    Classification and evolution of EF-hand proteins (1998)
    Springer
    BioMetals 11 (1998), S. 277-295 
    Details
    ISSN: 1572-8773
    Keywords: evolution ; classification ; EF-hand ; domain ; homology ; chimera ; congruence ; gene duplication ; gene fusion ; eukaryote ; dendrogram ; calmodulin ; troponin C ; light chain of myosin ; S100 ; parvalbumin ; calcineurin ; recoverin ; calpain ; sorcin ; diacylglycerol ; calbindin ; aequorin ; phospholipase C ; BM-40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Forty-five distinct subfamilies of EF-hand proteins have been identified. They contain from two to eight EF-hands that are recognizable by amino acid sequence as being statistically similar to other EF-hand domains. All proteins within one subfamily are congruent to one another, i.e. the dendrogram computed from one of the EF-hand domains is similar, within statistical error, to the dendrogram computed from another(s) domain. Thirteen subfamilies - including Calmodulin, Troponin C, Essential light chain, Regulatory light chain - referred to collectively as CTER, are congruent with one another. They appear to have evolved from a single ur-domain by two cycles of gene duplication and fusion. The subfamilies of CTER subsequently evolved by gene duplications and speciations. The remaining 32 subfamilies do not show such general patterns of congruence; however, some - such as S100, intestinal calcium binding protein (calbindin 9kd), and trichohylin - do not form congruent clusters of subfamilies. Nearly all of the domains 1, 3, 5, and 7 are most similar to other ODD domains. Correspondingly the EVEN numbered domains of all 45 subfamilies most closely resemble EVEN domains of other subfamilies. Many sequence and chem-ical characteristics do not show systemic trends by subfamily or species of host organisms; such homoplasy is widespread. Eighteen of the subfamilies are heterochimeric; in addition to multiple EF-hands they contain domains of other evolutionary origins.© Kluwer Academic Publishers
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    Experience, Awareness and Consciousness:Suggestions for Definitions as Offered by an Evolutionary Approach (2000)
    Springer
    Foundations of science 5 (2000), S. 429-456 
    Details
    ISSN: 1572-8471
    Keywords: awareness ; reflexive awareness and consciousness ; evolution ; experience and pattern matching ; symbolic language
    Source: Springer Online Journal Archives 1860-2000
    Topics: Natural Sciences in General
    Notes: Abstract An evolutionary point of view is proposed to make more appropriate distinctions between experience, awareness and consciousness. Experience can be defined as a characteristic linked closely to specific pattern matching, a characteristic already apparent at the molecular level at least. Awareness can be regarded as the special experience of one or more central, final modules in the animal neuronal brain. Awareness is what experience is to animals. Finally, consciousness could be defined as reflexive awareness. The ability for reflexive awareness is distinctly different from animal and human awareness and depends upon the availability of a separate frame of reference, as provided by symbolic language. As such, words have made reflexive awareness – a specific and infrequent form of awareness – possible. Conciousness might be defined as the experience evoked by considering, i.e. thinking about experiences themselves. If there is a hard problem of explaining consciousness, than this actually must be considered as the hard problem already met when trying to explain basic experience, since its nature remains elusive.
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    Dominance hierarchies and the evolution of human reasoning (1996)
    Springer
    Minds and machines 6 (1996), S. 463-480 
    Details
    ISSN: 1572-8641
    Keywords: Human reasoning ; evolution ; deontic reasoning ; transitive reasoning ; non-human primates ; neocortical ratio ; dominance hierarchy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Philosophy
    Notes: Abstract Research from ethology and evolutionary biology indicates the following about the evolution of reasoning capacity. First, solving problems of social competition and cooperation have direct impact on survival rates and reproductive success. Second, the social structure that evolved from this pressure is the dominance hierarchy. Third, primates that live in large groups with complex dominance hierarchies also show greater neocortical development, and concomitantly greater cognitive capacity. These facts suggest that the necessity of reasoning effectively about dominance hierarchies left an indelible mark on primate reasoning architectures, including that of humans. In order to survive in a dominance hierarchy, an individual must be capable of (a) making rank discriminations, (b) recognizing what is forbidden and what is permitted based one's rank, and (c) deciding whether to engage in or refriin from activities that will allow one to move up in rank. The first problem is closely tied to the capacity for transitive reasoning, while the second and third are intimately related to the capacity for deontic reasoning. I argue that the human capacity for these types of reasoning have evolutionary roots that reach deeper into our ancestral past than the emergence of the hominid line, and the operation of these evolutionarily primitive reasoning systems can be seen in the development of human reasoning and domain-specific effects in adult reasoning.
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    Syntax as an Emergent Characteristic of the Evolution of Semantic Complexity (1999)
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    Minds and machines 9 (1999), S. 309-346 
    Details
    ISSN: 1572-8641
    Keywords: language ; grammar ; syntax ; semantics ; evolution ; emergence ; brain size
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Philosophy
    Notes: Abstract It is commonly argued that the rules of language, as distinct from its semantic features, are the characteristics which most clearly distinguish language from the communication systems of other species. A number of linguists (e.g., Chomsky 1972, 1980; Pinker 1994) have suggested that the universal features of grammar (UG) are unique human adaptations showing no evolutionary continuities with any other species. However, recent summaries of the substantive features of UG are quite remarkable in the very general nature of the features proposed. While the syntax of any given language can be quite complex, the specific rules vary so much between languages that the truly universal (i.e. innate) aspects of grammar are not complex at all. In fact, these features most closely resemble a set of general descriptions of our richly complex semantic cognition, and not a list of specific rules. General principles of the evolutionary process suggest that syntax is more properly understood as an emergent characteristic of the explosion of semantic complexity that occurred during hominid evolution. It is argued that grammatical rules used in given languages are likely to be simply conventionalized, invented features of language, and not the result of an innate, grammar-specific module. The grammatical and syntactic regularities that are found across languages occur simply because all languages attempt to communicate the same sorts of semantic information.
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    Assessment of Hg2+ toxicity to a N2-fixing cyanobacterium in long- and short-term experiments (1992)
    Springer
    BioMetals 5 (1992), S. 149-156 
    Details
    ISSN: 1572-8773
    Keywords: Hg2+ toxicity ; cyanobacterium ; Nostoc calcicola ; growth ; photopigments ; nucleic acids ; photosynthesis ; membrane integrity ; nutrient uptake ; enzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Toxicological responses of the filamentous N2-fixing cyanobacteriumNostoc calcicola Bréb. towards Hg2+ were studied to enumerate the decisive lethal events. In low-dose, long-term experiments (0.05–0.25 μm Hg2+, 10 days), photoautotrophic growth was severely inhibited with concurrent loss of photosynthetic pigments (phycocyanin〉chlorophyll α〉carotenoids) and nucleic acids. The termination of growth after a day 4 exposure to 0.25 μm Hg2+ has been attributed to the complete inhibition ofin vivo photosynthetic activity in the cyanobacterium (O2 evolution〉14CO2 incorporation). The elevated Hg2+ concentrations irreversibly damaged the cell membrance as observed under light microscopy, and as indicated by the leakage of intracellular electrolytes and phycocyanin. In high-dose, short-term experiments (0.5–20.0 μm Hg2+, up to 6 h), thein vivo activities of selected enzymes (glutamine synthetase 〉 nitrate reductase 〉 nitrogenase) were less inhibited by Hg2+ than the uptake of nutrient ions (NH 4 + 〉NO 3 − 〉PO 4 3− ).
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    Effects of diet on growth, fecundity and duration of tethered flight of Nezara viridula (1984)
    Springer
    Entomologia experimentalis et applicata 35 (1984), S. 75-81 
    Details
    ISSN: 1570-7458
    Keywords: Nezara viridula ; insect dietetics ; growth ; fecundity ; flight capacity ; Heteroptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les effets du régime alimentaire pendant le 5ème stade sur les performances imaginales de N. viridula ont été déterminés en comparant la croissance, la fécondité, la durée du vol captif, et l'accumulation de corps gras chez des insectes élevés sur 4 régimes stérilisés. A partir de la formation des larves de 5ème stade, elles ont été alimentées sur haricots verts et arachides, ou transférées sur un régime formé exclusivement d'arachides, ou de haricots verts, ou de graines de soja ‘trempées’, cependant la durée du 5ème stade. Les insectes ont été transférés sur un régime de haricots verts et arachides à leur émergence. Les femelles élevées continuellement de haricots verts et arachides étaient plus lourdes (P〈0,01) à l'émergence (161,6 mg) que celles élevées sur haricots verts (146,3 mg) pendant le 5ème stade, et pondent plus d'oeufs (P〈0,08) pendant une durée de 34 jours (100,9 oeufs) que celles élevées sur arachides (54,7 oeufs). Plus de femelles élevées sur haricots verts et arachides (76,2%) pondent que celles élevées sur arachides (61,1%), soja ‘trempé’ (62,5%), ou haricots verts (60,9%). Les femelles élevées sur arachides volaient plus longtemps (P 〈 0,01) (42,9 mn) que celles élevées sur haricots verts (19,8 mn) pendant des vols captifs le 3ème jour après l'émergence. 78% de toutes les femelles élevées sur arachides volaient 〉-30 mn, contre 50% pour celles élevées sur haricots verts et arachides, ou soja ‘trempé’, et 35% pour celles élevées sur haricots verts. Seulement 7% des femelles élevées sur haricots verts volaient à la 60ème minute à la fin du test, contre 25% pour les femelles soja ‘trempé’, 33% pour les femelles haricots verts et arachides, et 47% pour celles élevées sur arachides. Les femelles ont été disséquées 34 jours après l'émergence pour déterminer l'importance du corps gras. Les indices de corps gras (Kiritani, 1963) montraient que les femelles élevées sur arachides (1,8) et graines de soja (1,7) ont apparemment un corps gras plus développé que celles élevées sur haricots verts et arachides (1,5), our haricots verts (1,2), pendant le 5ème stade. Ces résultats montrent que l'alimentation pendant le dernier stade larvaire de N. viridula affecte irréversiblement la croissance, la fécondité et l'aptitude au vol des femelles. En estimant que des résultats semblables auraient été obtenus avec des insectes élevés sur ces 4 aliments depuis l'éclosion, haricots verts et arachides constituent le meilleur aliment pour l'élevage de N. viridula. Ce régime fournit une graine mûre, vraisemblablement nécessaire pour l'accumulation d'un corps gras suffisant et une aptitude au vol migratoire, et une plante verte qui fournit les aliments apparement essentiels à l'ovogenèse.
    Notes: Abstract The effects of diet during the fifth stadium on performance of adult N. viridula were determined through comparing growth, fecundity, and duration of tethered flight of insects reared on four axenic diets: fresh green bean, raw-shelled peanut, a combination of the two and soaked soybean seed. Females reared on the combination diet were heavier than those reared on green beans and oviposited more than those reared on peanuts. Three-day-old adult females reared on peanuts flew longer than those reared on green beans. More females reared on diets containing mature seed showed a capacity for extended flight and had larger fat bodies at 34-days postemergence. Thus, inadequate diet during the fifth stadium irreversibly affected growth, development, reproduction and flight capacity.
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    Competition between larvae of Ips typographus (1986)
    Springer
    Entomologia experimentalis et applicata 41 (1986), S. 121-133 
    Details
    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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    Genetic variation in adaptation to foodplants among populations of the southern cowpea weevil,Callosobruchus maculatus: Evolution of oviposition preference (1986)
    Springer
    Entomologia experimentalis et applicata 42 (1986), S. 201-212 
    Details
    ISSN: 1570-7458
    Keywords: Callosobruchus maculatus ; Bruchidae ; Coleoptera ; behavior ; evolution ; genetic variation ; insect-plant interactions ; oviposition preference
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Vingt-deux lignées deC. maculatus Fab., liées à 6 plantes-hôtes, ont été examinées quant à leurs préférences — sans choix—parmi les graines de 9 légumineuses. Ces préférences se sont révél'ees semblables à celles observées lors de choix binaires; 3 paramètres ont donné les mêmes résultats: nombre moyen d'oeufs pondus par l'ensemble des femelles, nombre moyen d'oeufs émis par l'ensemble de celles acceptant la plante, fréquence des femelles acceptant la plante. L'analyse en composantes principales des préférences pour les 9 plantes a révélé que la majorité des mesures se situe sur les 2 premiers axes, qui ont rendu compte de 89% de la variation. Les performances des lignées sur le premier axe suggèrent qu'il s'agit d'un critère général de préférence. La classification automatique des plantes a montré un aspect général semblable à celui des composantes principales. Par ces 2 méthodes, les plantes ne se sont pas classées nettement selon leurs affinités taxonomiques. Bien que la classification automatique n'ait pas mis en évidence une similarité de comportement chez les insectes liés au même hôte, ceci était apparemment le cas. Les lignées liées à des hôtes présentant de fortes — ou à l'opoosé — de faibles préférences, ont montré différents seuils d'acceptation pour les 9 substrats de ponte. A l'opposé, il n'y a aucune preuve d'altération évolutive de la hiérarchie de préférences. On en a déduit que ces insectes étaient motivés par un petit nombre de stimulus, tels que les allélochimiques et al texture de tégument, pour déceler l'adéquation des substrats potentiels. (La microscopie électronique a suggéré une corrélation entre la texture du tégument et la hiérarchie des préférences de ces populations). La confiance dans les stimulus recueillis contribue à limiter les stratégies évolutives disponibles pour la population. A partir de là, la sélection en faveur —ou contre — des plantes, à l'origine, faiblement préférées, peut conduire, dans la niche de ponte, à l'incorporation — ou à l'exclusion — d'un groupe d'espèces taxonomiquemment éloignées, mais phénétiquement semblables. La probabilité d'altérations importantes de la hiérarchie des préférences paraît extrémement faible.
    Notes: Abstract A survey of 22 strains ofCallosobruchus maculatus associated with six different leguminous hosts indicates extensive genetic differentiation for oviposition preference. Female behavior suggests the existence of two distinct host preference groups among the nine oviposition substrates tested. Strains associated with plants in these two groups show distinct preference profiles. Genetic differentiation of oviposition preference is due to evolutionary modification of the threshold of acceptance of host plants, not to alteration of the preference hierarchy. From principal components analysis of these results, it is likely that very few independent plant traits govern oviposition preference.
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    Quantification of the impact of the hoverfly, Metasyrphus corollae on the cereal aphid, Sitobion avenae, in winter wheat: laboratory rates of kill (1987)
    Springer
    Entomologia experimentalis et applicata 43 (1987), S. 153-157 
    Details
    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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    L'élevage de deux coccinelles Harmonia axyridis et Semiadalia undecimnotata à l'aide d'oeufs d'Anagasta kuehniella tués aux rayons ultraviolets (1988)
    Springer
    Entomologia experimentalis et applicata 49 (1988), S. 235-244 
    Details
    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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    Basic rules of change (1990)
    Springer
    Journal for general philosophy of science 21 (1990), S. 231-257 
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    ISSN: 1572-8587
    Keywords: basic rules ; change ; discipline-neutral ; evolution ; analogy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Summary A small step is made in the direction of defining some general basic rules which can serve as a framework for research in several fields of the social sciences. The method of working with analogies asks for a more accurate approach. Starting from the concept of evolution in the form of a basic rule another basic rule is formulated. This rule shows what are the most important factors in long term developments and what types of development one can expect.
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    Evolution: Teleology or chance? (1991)
    Springer
    Journal for general philosophy of science 22 (1991), S. 133-141 
    Details
    ISSN: 1572-8587
    Keywords: evolution ; teleology ; chance ; purpose ; anthropomorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Summary Revaluation of the problem of natural teleology seems an important precondition for elucidating our environmental crisis and for formulating an ‘ecological ethics’, because it calls for a recognition of an intrinsic value in nature and organisms. Therefore, it is necessary to show that the concept of natural teleology is not in contradiction with scientific theories, in particular not with the theory of evolution. In this paper I shall argue that there is a fundamental misunderstanding about the concepts of teleology and chance in modern thinking. This as a result of a radical transformation of the Aristotelian concept of teleology by Christian theologians during the Middle Ages. This confusion resulted in the rejection of teleology from evolution and in an exaggeration of the role of chance. However, not a solution for the problem of teleology is given here, but only an attempt to prove that neither the fossil-record, nor the role of chance in evolution can give adequate arguments for the negation of teleology in evolution. That is not to say that, therefore there exists teleology in evolution, but the problem of teleology in nature cannot, be solved by the scientific theory of evolution, but only be elucidated by philosophical analysis. At the end of the paper it is argued that teleology must be rather presupposed in evolution.
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    Life and teleology (1992)
    Springer
    Journal for general philosophy of science 23 (1992), S. 85-103 
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    ISSN: 1572-8587
    Keywords: life ; teleology ; evolution ; reality ; representation ; experience
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Summary A comprehensive definition of the phenomenon called “life” led to the addition of many dimensions to the natural sciences, and especially the conscious mental dimension. Historical attention is paid not only to those employing the natural philosophical paradigms, but also to evolutionary theories and to the Kantian teleological philosophy. The belief that science can solve the riddle of life is a category of purposal thinking. A revised version of critical teleology is essential for comprehension of life.
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    Arbitrariness in nature: synergetics and evolutionary laws of prohibition (2000)
    Springer
    Journal for general philosophy of science 31 (2000), S. 57-73 
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    ISSN: 1572-8587
    Keywords: complex systems ; evolution ; nonlinearity ; pre-determination ; self-organization ; soft management ; structure-attractors ; synergetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract The philosophical consequences of synergetics, the interdisciplinary theory of evolution and self-organization of complex systems, are being drawn in the paper. The idea of discreteness of evolutionary paths is in the focus of attention. Although the future is open, and there are many alternative evolutionary paths for complex systems, not any arbitrary (either conceivable or desirable) evolutionary path is feasible in a given system. There are discrete spectra of possible evolutionary paths which are determined exclusively by inner properties of the corresponding systems. Synergetics allows us to reveal general laws of self-organization and, therefore, certain limits of arbitrariness of nature in choosing possible paths of evolution as well as in constructing of a complex evolutionary whole. A comparative analysis between the modern synergetic notions and a few ideas of the Western philosophy (F. Nietzsche, N. Hartmann, M. Heidegger) and of the Eastern teachings (Taoism, Buddhism) is made.
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    Ecology of black beetle Heteronychus arator. Influence of plant species on larval consumption, utilization and growth (1981)
    Springer
    Entomologia experimentalis et applicata 29 (1981), S. 109-116 
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    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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    Resistance in the wild crop relatives Avena macrostachya and Hordeum bogdani to the aphid Rhopalosiphum padi (1988)
    Springer
    Entomologia experimentalis et applicata 48 (1988), S. 225-232 
    Details
    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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    Effects of potassium levels over the range occurring in host plants on the growth of an insect herbivore (Manduca sexta) (1991)
    Springer
    Entomologia experimentalis et applicata 61 (1991), S. 59-72 
    Details
    ISSN: 1570-7458
    Keywords: Consumption ; food utilization efficiencies ; growth ; Lycopersicon esculentum ; Manduca sexta ; Nicotiana tabacum ; potassium ; tobacco hornworm ; water regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Third instar tobacco hornworms (Manduca sexta L.: Sphingidae) on low dietary potassium had a lower relative growth rate than individuals on diets with potassium concentrations reflecting those in host-plants, due to decreased consumption rate, lower efficiencies of conversion of ingested and digested food (ECI and ECD), and a prolonged growth/feeding phase. Furthermore, these larvae, when placed on a diet with a moderate potassium concentration through the fourth stadium, ended up being smaller due to lower ECI and less biomass gained, and had a prolonged growth phase, which suggest an irreversible cost of the previous low potassium diet. Third instar hornworms on high potassium diets had lower ECI and ECD, and they had a prolonged growth phase. These individuals, when placed on a moderate potassium diet in the fourth stadium, gained less biomass, than those previously offered hostplant-like-potassium diets. Body potassium concentrations (% dw) at the end of the third stadium were similar among treatment groups. With increasing potassium concentrations in the diet, utilization efficiencies of potassium decreased and potassium concentrations in the frass increased. Correspondingly, water content (% fw) of the newly-molted fourth instar larvae declined with increasing potassium, indicating a passive loss of water during potassium excretion. Low and high dietary potassium reduced survivorship of third instar larvae; fourth instar caterpillars previously fed the low potassium diet also had poor survivorship. We conclude that, within the normal range of potassium concentrations in the hostplants, caterpillar performance is largely unaffected by potassium concentration, but that potassium-poor and potassium-rich diets, such as those hornworms may sometimes experience, can reduce growth and survivorship.
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    Evolution of insect-plant relationships — a devil's advocate approach (1993)
    Springer
    Entomologia experimentalis et applicata 66 (1993), S. 3-12 
    Details
    ISSN: 1570-7458
    Keywords: evolution ; coevolution ; selection ; insect attack ; plant defense ; competition ; enemy free space ; chemoreception ; specialization ; plant recognition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Most hypotheses concerning the evolution of insect-plant relationships are based on the assumptions that, (1) phytophagous insects reduce plant fitness, and that (2) insect-plant relationships are the result of unconstrained selection. It can be shown, however, that there is little evidence to support these assumptions. As an alternative, it is proposed that the evolution of insect-plant relationships results primarily from autonomous evolutionary events; namely from heritable functional changes within the insects' nervous system that determine plant recognition and ultimately host plant specificity. These changes cannot be evoked by selective ecological agents. They originate from intrinsic changes (mutationssensu lato) within the insect genome. Ecological factors play a secondary role: by either supporting or preventing the establishment of the new genotype with the novel food preference.
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    URL: http://dx.doi.org/10.1007/BF02381541
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    Evolutionary genetics of the aphid Cryptomyzus, with a preliminary analysis of the inheritance of host plant preference, reproductive performance and host-alteration (1990)
    Springer
    Entomologia experimentalis et applicata 57 (1990), S. 65-76 
    Details
    ISSN: 1570-7458
    Keywords: Cryptomyzus ; aphid ; hybridization ; host plant preference ; reproductive performance ; host-alternation ; speciation ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé C. galeopsidis Kaltenbach contient plusieurs formes qui ont différentes relations avec des plantes hôtes et des cycles distincts. Des croisements ont permis d'élucider la taxonomie de ces formes et d'étudier l'hérédité de préférences d'hôtes, des performances reproductives et de l'alternance d'hôtes. Une des formes apparaît comme une espèce distincte par suite de la valeur adaptative réduite des hybrides. Les autres formes avec alternance ou non des hôtes sont considérées comme conspécifiques et représentant deux stratégies vitales différentes. Les performances reproductives sont probablement polygéniques puisque les hybrides ont des performances intermédiaires. Les préférences d'hôtes des hybrides montrent certains degrés de dominance et semblent déterminées par quelques gènes seulement. L'alternance des hôtes est envisagée comme ayant une hérédité monofactorielle. Les conséquences sur la spéciation sont discutées.
    Notes: Abstract The aphid species Cryptomyzus galeopsidis (Kaltenbach) includes several distinct forms which have different host plant relationships and life cycles. Cross breeding was used to elucidate the taxonomic status of these forms and to investigate the inheritance of host preference, reproductive performance and host-alternation. One of the forms appeared to be a distinct species because of the reduced fitness of the hybrids. Other host-alternating and non host-alternating forms are considered conspecific and represent two life cycle strategies. Reproductive performance is probably controlled polygenically, since hybrids show an intermediate performance. Host preference in hybrids showed some degree of dominance and seemed to be determined by only a few genes. Host-alternation is presumed to be inherited monofactorially. The implications for speciation are discussed.
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    Morality De-Kanted or the Biological Roots of Moral Behavior (2000)
    Springer
    International journal of value-based management 13 (2000), S. 297-308 
    Details
    ISSN: 1572-8528
    Keywords: morality ; moral systems ; behavior ; evolution ; adaptation ; natural selection ; altruism ; reciprocal altruism ; fitness ; reciprocity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract The ethical and moral behavior of Homo sapiens is no longer the exclusive domain of religion and philosophy because we recognize that such behavior affects the reproductive success of individuals within the species. We are a social species and therefore our survival is influenced by our capacity for cooperation and our willingness to take risks for kin. Emotions, some of which are found in other species, help to mediate our altruistic behavior. The reproductive benefits of helping kin, especially offspring, are readily seen. Helping non-kin can be beneficial if individuals can differentiate between ‘reciprocators’ and ‘non-reciprocators’ and direct altruistic behavior toward reciprocators. Also, if third parties are favorably impressed by observing altruistic behavior, the rewards need not come from the recipient of the altruistic behavior.
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    URL: http://dx.doi.org/10.1023/A:1007897311267
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    The Evolution of a Scientific Concept (1999)
    Springer
    Journal for general philosophy of science 30 (1999), S. 37-58 
    Details
    ISSN: 1572-8587
    Keywords: protein ; experimentation ; conceptual variation and selection ; evolution ; Mulder ; Liebig ; Pflüger ; Nägeli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract A philosophically comprehended account is given of the genesis and evolution of the concept of protein. Characteristic of this development were not shifts in theory in response to new experimental data, but shifts in the range of questions that the available experimental resources were fit to cope with effectively. Apart from explanatory success with regard to its own range of questions, various other selecting factors acted on a conceptual variant, some stemming from a competing set of research questions, others from an altogether different field of inquiry, and still others from the external environment. These results are best explained on, hence support, an evolutionary model of the progress of experimental investigation, whose outlines are briefly discussed.
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    URL: http://dx.doi.org/10.1023/A:1008246507186
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    Integrating neuroscience, psychology, and evolutionary biology through a teleological conception of function (1996)
    Springer
    Minds and machines 6 (1996), S. 481-505 
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    ISSN: 1572-8641
    Keywords: Neuroscience ; evolutionary psychology ; interfield theory ; evolution ; teleology ; function ; functionalism ; brain mapping ; language processing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Philosophy
    Notes: Abstract The idea of integrating evolutionary biology and psychology has great promise, but one that will be compromised if psychological functions are conceived too abstractly and neuroscience is not allowed to play a contructive role. We argue that the proper integration of neuroscience, psychology, and evolutionary biology requires a telelogical as opposed to a merely componential analysis of function. A teleological analysis is required in neuroscience itself; we point to traditional and curent research methods in neuroscience, which make critical use of distinctly teleological functional considerations in brain cartography. Only by invoking teleological criteria can researchers distinguish the fruitful ways of identifying brain components from the myriad of possible ways. One likely reason for reluctance to turn to neuroscience is fear of reduction, but we argue that, in the context of a teleological perspective on function, this concern is misplaced. Adducing such theoretical considerations as top-down and bottom-up constraints on neuroscientific and psychological models, as well as existing cases of productive, multidisciplinary cooperation, we argue that integration of neuroscience into psychology and evolutionary biology is likely to be mutually beneficial. We also show how it can be accommodated methodologically within the framework of an interfield theory.
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    URL: http://dx.doi.org/10.1007/BF00389655
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    Lipaemia and liver composition in pregnant rats consuming olive oil and olive oil used for frying (1997)
    Springer
    European journal of nutrition 36 (1997), S. 205-213 
    Details
    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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    Effects of porcine somatotropin on the chemical body composition and fat quality in growing-finishing pigs (1997)
    Springer
    European journal of nutrition 36 (1997), S. 294-298 
    Details
    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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    Colonization and evolution of lakes on the central Norwegian coast following deglaciation and land uplift 9500 to 7800 years B.P. (1997)
    Springer
    Journal of paleolimnology 18 (1997), S. 269-281 
    Details
    ISSN: 1573-0417
    Keywords: colonization ; evolution ; lakes ; Norway ; deglaciation ; land uplift ; invertebrates ; Chironomidae ; Porifera ; Bryozoa ; diatoms ; Charophyta ; tsunami
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Invertebrate colonization of lakes following the uplift of land from the sea was studied in four lakes, currently situated between 39 and 24 m a.s.l., on the central Norwegian coast. The lakes were isolated from the sea between 9500 and 7700 years B.P. Animal and algal remains picked from core samples showed that the first colonizers preserved as fossils were usually members of the Chironomidae, Daphnidae/Chydoridae, Acarina, Porifera (Ephydatia mülleri and Spongilla lacustris), Bryozoa (Cristatella mucedo and Plumatella spp.) and Charophyta (Chara sp.). Of the chironomids, the genus Chironomus was present in the oldest lacustrine layers of all four lakes, but other genera recorded at the marine/lacustrine boundary were Dicrotendipes, Procladius (?), Einfeldia, Microtendipes, and Glyptotendipes. Remains of the caddis fly family Limnephilidae were also present in the earliest lacustrine sediments in Kvennavatnet and Kvernavatnet. The oldest invertebrate fauna is typical for mesotrophic lakes. However, chironomids and mites have been present in this area from at least about 10 500 years B.P. A diverse chironomid community was established between 300 and 800 years after isolation from the sea at Kvernavatnet on the island of Hitra, while only between 80 and 120 years passed before a comparably diverse community developed at Kvennavatnet on the mainland coast. A similar development of the invertebrate fauna occurred in Kvennavatnet, Kvernavatnet and Storkuvatnet. However, Litjvatnet deviates greatly from the ‘normal’ pattern because a tsunami disturbed the bottom sediments and fauna. The tsunami, a gigantic sea wave, was caused by a submarine slide from the Norwegian continental slope. It reached Litjvatnet, today located 24 m a.s.l., but was not traced in Storkuvatnet at 30 m a.s.l. This event happened about 7200 years B.P.
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    URL: http://dx.doi.org/10.1023/A:1007934825272
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    Sources of Sectoral Growth in an Economy Wide Context: The Case of U.S. Agriculture (1997)
    Springer
    Journal of productivity analysis 8 (1997), S. 293-310 
    Details
    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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    URL: http://dx.doi.org/10.1023/A:1007759705652
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    Charophyta: their use in paleolimnology (1994)
    Springer
    Journal of paleolimnology 10 (1994), S. 43-52 
    Details
    ISSN: 1573-0417
    Keywords: Charophyta ; evolution ; gyrogonite morphology ; ecology-paleoecology ; Argentina ; South America
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Charophyta are common algae in limnic waters from many regions and are an interesting group from an evolutionary point-of-view, as they are believed to be related to the Chlorophyceae and land plants. Paleontological-botanical systematics are discussed, taking into consideration some new advances. Charophytes live in all types of inland waters and are sensitive to ecological change, and so they are very useful paleolimnological markers. Gaps concerning gyrogonite morphology in extant taxa and their responses to different environmental conditions must be described. This paper discusses data concerning ecological factors affecting the distribution of Argentinian Charophyta (principally distributed between 30°S and 40°S), gyrogonite morphology related to different ecological conditions, and the way that Charophyta can modify the environment.
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    URL: http://dx.doi.org/10.1007/BF00683145
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    Pleistocene Charophyta from Arroyo Perucho Verna, Province of Entre Rios, Argentina (1994)
    Springer
    Journal of paleolimnology 10 (1994), S. 53-58 
    Details
    ISSN: 1573-0417
    Keywords: Charophyta ; evolution ; gyrogonite morphology ; ecology-paleoecology ; Argentina ; South America
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract The Pleistocene charophytes from Arroyo Perucho Verna, Province of Entre Ríos, were analyzed.Chara contraria Br. ex Kütz.,C. contraria var.longilinea Cáceres,C. globularis Thuill. andTolypella intricata (Trent. ex Roth.) Leonh. var.apiculata (A. Br.) Wood were described and illustrated with scanning electron microscope. The assemblage indicates fresh alkaline to slightly saline waters, not very deep, in a lentic or sometimes lotic environment. Extant assemblages provide data for this paleoecological reconstruction.
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    Optimal concentration of ammonium ion in a minimal synthetic medium for the growth of Candida albicans (1991)
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    Mycopathologia 113 (1991), S. 139-142 
    Details
    ISSN: 1573-0832
    Keywords: Candida albicans ; ammonium ; physiology ; medium ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Candida albicans strain B 311-10 with and without starvation was cultivated in the minimal synthetic medium of Shepherd et al. [18], modified without biotin, aminoacids, low glucose concentration [20] and with decreasing amounts of (NH4)2SO4, to determine the optimal growth requirement for this strain. All the experiments were carried out under sterile conditions at 25 °C in a thermostat with initial O.D.s (675 nm) of 0.500 and 0.100. Cell growth was generally monitored everyday for six days with a spectrophotometer by determining the absorbance of the cultures at 675 nm. All the experiments were repeated three times and a statistical analysis of the data with a probability of 99% and 1% of error was performed to confirm the validity of the results. Best growth was obtained with starved cells at an initial O.D. of 0.100 and with a 0.1 g/L concentration of (NH4)2SO4. At this concentration, the growth of C. albicans B 311-10 was best between the first and the fourth day with the maximum at the third day. With (NH4)2SO4 concentrations of 0.05 and 0.5 g/L, cell growth was the same.
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    The growth of Epidermophyton floccosum and E. stockdaleae at different temperatures (1990)
    Springer
    Mycopathologia 112 (1990), S. 157-163 
    Details
    ISSN: 1573-0832
    Keywords: Epidermophyton floccosum ; E. stockdaleae ; growth ; incubation temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The ability of 17 strains of genus Epidermophyton (15 strains belonging to Epidermophyton floccosum, one to E. floccosum var. nigricans and one to E. stockdaleae) to grow at different temperatures (4 °C, 25 °C, 28 °C, 31 °C, 34 °C, 37 °C and 40 °C) was stated. The strains were inoculated on Sabouraud Dextrose Agar and regularly controled over a period of 14 days when the plates were incubated at 25 °C, 28 °C, 31 °C, 34 °C, 37 °C and 40 °C, and over a period of 70 days when the temperature was 4 °C. The optimal growth of E. floccosum was observed at 28 °C and 31 °C, and no signs of growth were recorded neither at 4 °C nor at 40 °C. The optimal development of E. stockdaleae was observed at 25 °C and 28 °C. This species grew from 4 °C to 31 °C.
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    Yield and growth response to potassium of grain sorghum as influenced by variety in a savanna soil of Nigeria (1988)
    Springer
    Nutrient cycling in agroecosystems 16 (1988), S. 217-226 
    Details
    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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    Biomass and nutrient uptake ofAilanthus excelsa as affected by N and P fertilization on an aridisol (1994)
    Springer
    Nutrient cycling in agroecosystems 40 (1994), S. 243-250 
    Details
    ISSN: 1573-0867
    Keywords: Ailanthus excelsa ; biomass ; growth ; N and P fertilizers ; N content ; N uptake ; P content ; P update ; silvicultural efficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A field experiment was conducted on a coarse sand soil having pH 8.8 and organic matter 0.06% in Indian arid region, to study the influence of N and P fertilizers on growth, biomass and nutrient content ofAilanthus excelsa, which is an important fodder species of arid and semi arid regions. Three levels of nitrogen (0, 9 and 18 g N tree−1 as Urea) and of phosphorus (0, 3 and 6 g P2O5 tree−1 as Single Superphosphate) in factorial combinations were taken in triplicate and the experiment was laid in Randomised Block Design. Application of 9 g N plant−1 improved tree height by 15 to 25%, collar circumference by 30 to 37% and crown diameter by 18 to 26% in the initial 3 years. Total biomass increase due to 9 g N plant−1 was 76% and 59%, respectively, after 1 and 2 years of planting. Application of 3 g P2O5 tree−1 increased tree height by 8 to 18% and collar circumference by 17 to 24% during initial three years, and total biomass by 70% at 1 year and 30% at 2 years of age. Combined application of 18 g N and 3 g P2O5 tree−1 (N18P3) was the best treatment which increased tree height by 49%, 85% and 35% and collar circumference by 56%, 10% and 11% at 1, 2, and 3 years of age, respectively. N18P3 treatment increased the total biomass by 181% at 1 year and 185% at 2 years of age. N and P applications improved considerably the branching of roots and root length and enhanced root biomass by 2 to 3 folds. N18P3 treatment increased the nitrogen uptake by 304% (4.02 g tree−1) at 1 year and 211% (42.56 g tree−1) at 2 years of age. The P uptake was maximum (290.4 mg tree−1) due to N18P3 treatment in 1 year old and 11.37 g tree−1 due to N9P6 treatment in 2 year old plantation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750471
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  • 97
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    Do Small Innovating Firms Outperform Non-Innovators? (2000)
    Springer
    Small business economics 14 (2000), S. 195-210 
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    ISSN: 1573-0913
    Keywords: growth ; manufacturing ; performance ; product innovation ; small firms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract The paper considers the relative performance [along a number of parameters] of a sample of 228 small manufacturing firms categorised by level of innovation. Whilst innovators appear no more likely to have experienced some form of sales or employment growth, they are significantly more likely to have grown more. In other words, the innovators' growth rate distributions are highly negatively skewed. With regards to export intensities, profitability and productivity levels, the findings are less clear. On the whole, the results reported here are similar to those of other small firm studies, yet vary markedly from large firm equivalents; suggesting that the nature of the returns to innovation may be contingent, at least in part, upon firm size. Moreover, the high levels of variation in firm performance should caution us against proffering innovative imperatives. If we are to counsel firms to "innovate at all costs", we must be clear about, and clearly demonstrate, the nature of the returns they may reasonably expect and the processes through which these may be optimised.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008100206266
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  • 98
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    A mathematical model of plant growth with particular reference to winter wheat (1987)
    Springer
    Nutrient cycling in agroecosystems 11 (1987), S. 245-266 
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    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01063321
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  • 99
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    Electronic Resource
    A mathematical model of root exploration and of grain fill with particular reference to winter wheat (1987)
    Springer
    Nutrient cycling in agroecosystems 11 (1987), S. 267-281 
    Details
    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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    URL: http://dx.doi.org/10.1007/BF01063322
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  • 100
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    Electronic Resource
    Effects of rate and timing of nitrogen dressings on grain yield formation of winter wheat (T. aestivum L.) (1980)
    Springer
    Nutrient cycling in agroecosystems 1 (1980), S. 177-190 
    Details
    ISSN: 1573-0867
    Keywords: winter wheat ; nitrogen uptake ; autumn dressing ; split-dressing ; growth ; grain yield ; protein content ; harvest-index
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A field experiment with the winter wheat cultivar Donata was carried out on a fine-textured river clay soil in 1978. The rates of nitrogen dressing ranged from 0 to 160 kg N per ha and were split over from one up to three application times: autumn, early spring and late spring. Total above-ground dry matter and grain dry-weight yields ranged from 9.1 to 13.7 tons per ha and from 4.17 to 6.35 tons per ha, respectively. Late top-dressings increased the harvest-index, whereas an autumn dressing had the opposite effect. Number of culms per m2, grain weight (mg) and grain number per m2 increased from 350 to 430, from 35.5 to 36.8 and from 11 680 to 16 980, respectively, as the nitrogen dosage was raised from 0 to 160 kg N per ha. The linear rate of grain growth ranged from 111 to 172 kg dry matter per ha per day with nitrogen doses from 0 to 160 kg N per ha. Differences in rate of grain growth per unit area were mainly related to number of grains per m2. The association between grain number and grain yield was reflected by a correlation coefficient of 0.97 (n = 32). A higher level of nitrogen dressing enhanced the leaf area index and leaf area duration. However, we could not derive an effect of nitrogen on the duration of grain growth. Total nitrogen yield ranged from 71 to 166 kg N per ha and grain nitrogen yield from 54 to 122 kg N per ha with nitrogen dosages of 0 and 160 kg N per ha, respectively. The nitrogen concentration of the grains varied between 1.3 and 2.0 N. An autumn dressing of 40 kg N per ha generally showed only minor effects on yield and yield components. Top dressings during spring resulted in a higher recovery and efficiency of the applied nitrogen. Therefore, it may be concluded from this experiment and literature that on fertile soils an autumn dressing of nitrogen will not be economical, but split-dressings in spring are very beneficial. In particular, a late nitrogen application during the boot stage increased grain number, harvest-index and grain yield as well as protein concentration of the grain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01053130
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