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  • 1
    Electronic Resource
    Electronic Resource
    Soldier production inCamponotus novaeboracensis during colony growth (1989)
    Springer
    Insectes sociaux 36 (1989), S. 28-41 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume Dans des colonies d'importance différente chez la fourmi charpentièreCamponotus novaeboracensis, on a observé des changements dans les équations allométriques, les courbes de fréquence de taille et la distribution des castes. Les colonies naturelles ont été groupées en trois catégories selon le nombre d'ouvrières dans une colonie: colonie «juvénile» pour moins de 150 ouvrières, colonie «prémature» pour 200 à 2000 ouvrières et colonie «mature» pour plus de 2000 ouvrières et ayant produit des sexués. Il n'y avait pas de différence dans les équations allométriques entre les trois catégories, néanmoins les colonies «matures» contenaient un plus grand nombre de soldats. On a noté des différences notables dans les courbes de fréquence de taille des trois catégories.
    Notes: Summary Changes in allometry equations, size-frequency curves, and caste ratios were examined in different-sized colonies of the polymorphic carpenter antCamponotus novaeboracensis. Field collected colonies broadly grouped into three categories based on the number of workers in a colony: “incipient” if they had fewer than 150 workers, “juvenile” if they had 200 to 2,000 workers, and “mature” if they had more than 2,000 workers and had produced reproductives. There was no difference in the allometry equations between the three groups, but the mature colonies did contain a higher proportion of soldiers. The size-frequency histograms and caste ratios were significantly different between the three groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02225878
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  • 2
    Electronic Resource
    Electronic Resource
    Internal material damping of polymer matrix composites under off-axis loading (1985)
    Springer
    Journal of materials science 20 (1985), S. 2575-2585 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The objective of this paper is to determine theoretically the material damping of short fibre-reinforced polymer matrix composites. The major damping mechanism in such composites is the viscoelastic behaviour of the polymer matrix. The analysis was carried out by developing a finite-element program which is capable of evaluating the stress and strain distribution of short fibre composites under axial loading (see Fig. 1a). Using the concept of balance of force we can express the modulusE x along the loading direction as a function of the mechanical properties of the fibre and matrix materials, fibre aspect ratio,l/d, loading angle,θ, and fibre volume fraction,V f. Then we apply the elastic-viscoelastic correspondence principle to replace all the mechanical properties of the composite, fibre and matrix materials such asE x,E f,E m,G m, by the corresponding complex moduli such asE x ′ +iE x ″ , andE f ′ +iE f ″ . After separation of the real and imaginary parts, we can expressE ' x/t' andE x t" as functions of the fibre aspect ratio,l/d, loading angle,θ, stiffness ratio,E f/E m, fibre volume fraction,V f, and damping properties of the fibre and matrix materials such asη f andη m. Numerical results of the composite storage modulus,E x ′ , loss modulus,E x ″ , and loss factor (damping),η C, are plotted as functions of parameters such asl/d,θ,V f, and are discussed in terms of variations ofl/d,θ, andE f/E m, in detail. It is observed that for a given composite, there exist optimum values ofl/d andθ at whichE x ″ andη c are maximized. The results of this paper can be used to optimize the performance of composite structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00556089
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  • 3
    Electronic Resource
    Electronic Resource
    Prediction of material damping of laminated polymer matrix composites (1987)
    Springer
    Journal of materials science 22 (1987), S. 1006-1012 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract In this study the material damping of laminated composites is derived analytically. The derivation is based on the classical lamination theory in which there are eighteen material constants in the constitutive equations of laminated composites. Six of them are the extensional stiffnesses designated by [A] six of them are the coupling stiffnesses designated by [B] and the remaining six are the flexural stiffnesses designated by [D]. The derivation of damping of [A], [B] and [D] is achieved by first expressing [A], [B] and [D] in terms of the stiffness matrix [Q](k) andh k of each lamina and then using the relations ofQ ij (k) in terms of the four basic engineering constantsE L,E T, GLT andv LT. Next we apply elastic and viscoelastic correspondence principle by replacingE L,E T...by the corresponding complex modulusE L *,E T *,..., and [A] by [A]*, [B] by [B]* and [D] by [D]* and then equate the real parts and the imaginary parts respectively. Thus we have expressedA ij ′,A y ″,B ij ′,B ij ″, andD ij ″ in terms of the material damping ηL (k) and ηT (k)...of each lamina. The damping ηL (k), ηT (k)...have been derived analytically by the authors in their earlier publications. Numerical results of extensional damping lη ij =A ij ″/A ij ′ coupling dampingcη ij =B ij ″/B ij ′ and flexural damping Fη ij =D ij ″/D ij ″ are presented as functions of a number of parameters such as fibre aspect ratiol/d, fibre orientation θ, and stacking sequence of the laminate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01103543
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  • 4
    Electronic Resource
    Electronic Resource
    Effect of particle concentration on filter- and particulate-feeding in the herring Clupea harengus (1985)
    Springer
    Marine biology 88 (1985), S. 109-116 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Observations were made in the laboratory on the feeding behaviour of small shoals of captive juvenile herring (Clupea harengus) using Artemia sp. nauplii as food. The fish used two methods of feeding. The first, filter-feeding, was only used at concentrations exceeding approximately 50 nauplii l-1. Filter-feeding rapidly gave way to particulate-feeding (biting and gulping) as concentrations declined, and biting was the only method used when concentrations were 〈 50 nauplii l-1. There was a positive correlation between particle concentration and feeding acts of both types. Particle concentrations declined exponentially throughout experiments, indicating that a constant proportion was being removed during an experiment. This proportion was inversely related to the initial concentration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00397157
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  • 5
    Electronic Resource
    Electronic Resource
    Resistance to potato leaf roll virus and potato virus Y in somatic hybrids between dihaploid Solanum tuberosum and S. brevidens (1988)
    Springer
    Theoretical and applied genetics 76 (1988), S. 113-117 
    Details
    ISSN: 1432-2242
    Keywords: Potato ; Solanum brevidens ; somatic hybrid ; PLRV ; PVY
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Many somatic fusion hybrids have been produced between a dihaploid potato Solanum tuberosum and the sexually-incompatible wild species S. brevidens using both chemical and electrical fusion techniques. S. brevidens was resistant to both potato leaf roll virus (PLRV) and potato virus Y (PVY), the viruses being either at low (PLRV) or undetectable (PVY) concentrations as determined by enzyme-linked immunosorbent assay (ELISA). The S. tuberosum parent was susceptible to both viruses. A wide range of resistance, expressed as a decrease in virus concentration to both viruses was found amongst fusion hybrids, four of which were especially resistant. The practicality of introducing virus resistance from S. brevidens into cultivated potatoes by somatic hybridisation is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00288840
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  • 6
    Electronic Resource
    Electronic Resource
    Dispersion of displaying male sage grouse (1989)
    Springer
    Behavioral ecology and sociobiology 24 (1989), S. 1-14 
    Details
    ISSN: 1432-0762
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The distribution of lek sizes was examined in each of three populations of sage grouse in eastern California. Peak seasonal lek sizes collected over a 35 year period were found to covary among the three sites indicating that some global environmental or demographic features modulated male attendance in any given year. Despite these annual variations, the ranks of the three populations with regard to mean lek size remained stable. In all three populations, there was a persistent excess of small and large leks, compared to random settlement on the same number of sites, and a consistency in the ranking by size of particular sites in successive years. The sequential phenology of lek site occupation in each population was correlated with recolonization of habitats surrounding central wintering refuges each spring. Some lek sites utilized for display in early spring were regularly abandoned prior to the onset of mating as more peripheral leks became active. On top of population, site, and seasonal variations in lek size, pronounced daily fluctuations in attendance were common. Multivariate regressions indicated that an average 36% of the daily variation in male numbers was correlated with weather variables, female attendance levels, and prior raptor harassment. Several outcomes of the analyses support the notion that dispersion of males is partly determined by male settlement on current female traffic patterns (hotspot settlement). The analyses also suggest that display is sufficiently costly that variations in male attendance are in part a result of conflicts between strutting and thermoregulatory expenditures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00300112
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  • 7
    Electronic Resource
    Electronic Resource
    Sexual selection in lekking sage grouse: phenotypic correlates of male mating success (1985)
    Springer
    Behavioral ecology and sociobiology 18 (1985), S. 117-123 
    Details
    ISSN: 1432-0762
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mate choice cues in sage grouse were reinvestigated by analyzing relationships between male mating success and a range of suggested cues. Display cues were implicated by significant relationships between mating status (whether or not a male mated) and lek attendance, display rate (corrected for effects of female proximity and time of day) and an acoustic component related to temporal and frequency measure of a whistle emltted during the strut display. Although display rate and the acoustic component were intercorrelated, both exerted significant partial effects on mating success in mutivariate analyses. These display measures also differed significantly between males. In contrast, mating success was not significantly related to measures of territory characteristics, including size and proximity to the lek center, or to body size. These results resolve discrepancies between previous studies and provide a basis for experimental analysis of the role of female choice in this lek system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00299040
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  • 8
    Electronic Resource
    Electronic Resource
    Dispersion of displaying male sage grouse (1989)
    Springer
    Behavioral ecology and sociobiology 24 (1989), S. 15-24 
    Details
    ISSN: 1432-0762
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The degree to which male sage grouse select lek sites and females select nesting sites to maximize proximity to the other sex was examined by contrasting male dispersions with the dispersions and movements of females in the months preceeding incubation. Wintering females exhibit highly overlapping ranges due to shared use of central refuging areas. In late winter and early spring, females move an average 9 km from wintering areas to select nest sites and males begin occupying leks. Pooled evidence suggests that females select nest sites independently of male dispersion whereas males adjust lek occupation so as to maximize proximity to females. Relevant observations include females visiting nest sites before leks, moving further to select a nest site than to select a lek, and increasing their distance to leks as a result of selecting nest sites. In addition, males avoid leks until females have moved to within 5 km of the arenas, abandon early season leks as local female densities drop, and exhibit dispersions in which mean ratios of females/male are similar across leks. Contrasts between predicted and observed dispersions of males showed that hotspot settlement models are adequate to explain male dispersions on very coarse scales (2 km or greater); on finer scales, habitat preferences of males and tendencies for males to cluster tightly must be invoked in addition to hotspots to explain specific lek sitings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00300113
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  • 9
    Electronic Resource
    Electronic Resource
    Field playback of male display attracts females in lek breeding sage grouse (1989)
    Springer
    Behavioral ecology and sociobiology 24 (1989), S. 439-443 
    Details
    ISSN: 1432-0762
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Recent correlational studies of lekking sage grouse suggest that male vocal display attracts females. To test this hypothesis further, the natural displays of a territorial male were supplemented with the tape-recorded display of another, reproductively-successful, individual. Significantly, more females approached the speaker's location on days when the recording was played, and also on non-playback days immediately following a playback, than on other non-playback days (Fig. 1). Analysis of male displays indicated that females were responding to the playback itself rather than to changes in male behavior. The “after-response” following a playback suggests that some females present during a playback remembered its location and approached on a subsequent lek visit. The results provide necessary support for the epigamic function of vocal display, and suggest ways in which female responses to male display may influence lek structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00293273
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  • 10
    Electronic Resource
    Electronic Resource
    Advantages of a soluble dye in blot immunobinding assays for virus detection in potatoes (1988)
    Springer
    Potato research 31 (1988), S. 389-394 
    Details
    ISSN: 1871-4528
    Keywords: potato leafroll virus ; potato virus Y ; virus diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A technique is described in which plant sap is blotted onto small pieces (8×11 mm) of nylon membrane and virus particles bound to the paper are detected by a modification of the enzymelinked immunosorbent assay (ELISA). The detectable product of the assay is a soluble yellow dye, the absorbance of which increased with the virus content of the plant sap. Leaf or tuber sap from plants secondarily-infected with either potato leafroll virus or potato virus Y could be clearly distinguished from that of healthy plants and a majority of tubers primarily infected with PVY were also detected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02357874
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