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  • Ultrastructure  (78)
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  • CR: 5.17
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  • California Institute of Technology Pasadena
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  • 1
    Digitale Medien
    Digitale Medien
    The effect of variation in host plant on the growth of an oligophagous insect, Malacosoma americanum and its polyphagous relative, Malacosoma disstria (1981)
    Springer
    Entomologia experimentalis et applicata 30 (1981), S. 163-168 
    Details
    ISSN: 1570-7458
    Schlagwort(e): host-plant relations ; host variation ; Malacosoma americanum ; Malacosoma disstria ; Lasiocampidae ; Geometridae ; Lepidoptera ; niche breadth ; specialization ; plantinsect interactions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Raupen von Malacosoma americanum (F.), einer oligophagen Art, die sich vor allem auf Prunus und andern baumartigen Rosaceen entwickelt, wurden verglichen mit Raupen der polyphageren Verwandten M. disstria Hb. und zwar im Hinblick auf deren Empfindlichkeit auf Unterschiede im Blatt ihrer gemeinsamen Wirtspflanze, Prunus serotina Ehrh. Das Puppengewicht und die Entwicklungszeit bis zur Verpuppung wurden gemessen bei Raupen, welche auf Blättern von freiwachsenden und von beschatteten Jungpflanzen gezüchtet worden waren. Die Blattunterschiede hatten eine ausgesprochene Wirkung, aber es gab keine Unterschiede in der Reaktion der beiden Arten. Dieser Vergleich lässt vermuten, dass die Empfindlichkeit auf intraspezifische Unterschiede der Wirtspflanzenqualität bei wirtsspezifischen und polyphagen Arten gleich ist. Indessen dürften sich laut anderen Resultaten einige Insektenarten anders verhalten.
    Notizen: Abstract Larvae of Malacosoma americanum (F.)(Lepidoptera: Lasiocampidae) an oligophagous species that feeds primarily on Prunus and other rosaceous trees, were compared to larvae of the more highly polyphagous congener M. disstria Hb., with respect to their sensitivity to variation in the foliage of a common host plant, Prunus serotina Ehrh. Pupal weight and time to pupation were measured on larvae reared on foliage from open-grown and from shaded saplings. The difference in foliage had a pronounced effect, but no difference was evident between the species in their response to the variation in foliage. This comparison implies that sensitivity to intraspecific variation in host quality does not differ between host-specific and generalized species. However, results from other species suggest that some species of insects do differ in this respect.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300882
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  • 2
    Digitale Medien
    Digitale Medien
    Food plant specialization and feeding efficiency in the tent caterpillars Malacosoma disstria and M. americanum (1981)
    Springer
    Entomologia experimentalis et applicata 30 (1981), S. 106-110 
    Details
    ISSN: 1570-7458
    Schlagwort(e): assimilation efficiency ; growth efficiency ; niche breadth ; specialization ; hostplant relations ; plant-insect interactions ; Malacosoma americanum ; Malacosoma disstria ; Lasiocampidae ; Lepidoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Raupen von Malacosoma americanum, einer oligophagen Art, die sich vor allem auf Prunus und andern baumartigen Rosaceen. entwickelt, wurden mit Raupen der polyphageren Verwandten M. disstria in Hinblick auf die Verwertung der Blätter ihres gemeinsames Wirtes Prunus serotina verglichen. Wirerhielten ähnliche Werte wie sie früher für andere Lepidopteren publiziert worden waren und zwar in Bezug auf die üblichen Messwerte, Anteil verwertete Nahrung, Wachstum in Trockengewicht pro Einheit gefressene oder verwertete Nahrung. Zudem unterschieden sich die beiden Arten in keiner Masszahl für Effizienz. Unsere Resultate sind im Einklang mit der Folgerung, das spezialisierte phytophage Insekten ihre Wirtspflanzen nicht besser ausnützen als as polyphage Arten tun.
    Notizen: Abstract Larvae of Malacosoma americanum (F.) an oligophagous species that feeds primarily on Prunus and other rosaceous trees, were compared to larvae of the more highly polyphagous congener M. disstria Hb., with respect to the efficiency of utilization of the foliage of a common host plant, Prunus serotina Ehrh. We obtained values similar to those reported for other Lepidoptera for the commonly used measures of the fraction of ingested food that was assimilated, and for the growth in dry weight per unit of food ingested or assimilated. Moreover, the two species did not differ in any measure of efficiency. Our results are compatible with the conclusion that specialized phytophagous insects do not use their host plants with greater physiological efficiency than do generalized insects.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300873
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  • 3
    Digitale Medien
    Digitale Medien
    Host races and sympatric speciation in small ermine moths, Yponomeutidae (1981)
    Springer
    Entomologia experimentalis et applicata 30 (1981), S. 280-292 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Allozyme variation ; Lepidoptera ; Yponomeuta padellus ; evolutionary stages ; F-statistics ; panmixis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Le degré de différenciation génétique en allozymes à des niveaux divers de divergence évolutive (populations conspécifiques, sibling species et non-sibling species) d'Yponomeuta a été déterminé. Les distances génétiques entre des sibling species ou des non-sibling species sont très larges. Il en est conclu que de telles estimations ne fournissent pas beaucoup d'informations sur le phénomène de spéciation même. Des coéfficients de reproduction consanguine (F ST) ont été calculés pour des populations d'Y. padellus provenant de six plantes-hôtes. La valeur moyenne F STest .030±.012. Les valuers de F ST des populations recueillies sur Crataegus, (plante-hôte habituelle d'Y. padellus), sont inférieures 2–3.5 fois à celles des populations de l'ensemble des autres plantes-hôtes. L'apparition de races en fonction de l'hôte, mesurée par les différences importantes dans de fréquences des allozymes entre populations sympatriques sur plusieurs plantes-hôtes, a été examinée dans quatre régions. Il apparaît ainsi que la formation de races en fonction de l'hôte se produit chez Y. padellus et que la spéciation sympatrique est un évènement très vraisemblable.
    Notizen: Abstract The amount of genetic differentiation at various levels of evolutionary divergence (conspecific populations, sibling species and non-sibling species) in Yponomeuta was determined. Genetic distances between siblings or non-siblings were found to cover a wide range. It is concluded that such estimates do not give much information on the speciation process itself. Inbreeding coefficients were calculated for populations of Y. padellus from a total of six host plants. The grand mean F ST value is 0.030±0.012. F ST values for populations sampled from Crataegus, the common food plant of Y. padellus, are 2–3.5 times smaller than those for populations from the other food plants taken together. Host race formation, as measured by significant differences in allozyme frequencies between sympatric populations on two or more food plants, was investigated in four areas. Host race formation seems to occur in Y. padellus and sympatric speciation is a likely event.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00347708
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  • 4
    Digitale Medien
    Digitale Medien
    Repellency of pheromones released by females of Heliothis armigera and H. zea to females of both species (1981)
    Springer
    Entomologia experimentalis et applicata 30 (1981), S. 123-127 
    Details
    ISSN: 1570-7458
    Schlagwort(e): Sex Pheromones ; Repellent ; Heliothis armigera ; Heliothis zea ; Lepidoptera ; Noctuidae ; cotton bollworm ; corn earworm
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé L'examen en olfactomètre a porté sur les réactions face à d'autres femelles de la même espèce, de femelles vierges ou ayant copulé d'Heliothis armigera Hübner et H. zea Boddie. Le lot comprenait 8 femelles, vierges ou ayant copulé en présence d'une femelle vierge ou ayant copulé. Les 4 combinaisons possibles de femelles vierges et de femelles ayant copulé ont été examinées avec 12 répétitions pour chaque espèce. Un extrait de l'extrémité de l'abdomen de femelles vierges d'une espèce a été présenté aux femelles de l'autre espèce pour examiner les possibilités de réactions interspécifiques aux phéromones. Pour chaque espèce, les réactions interspécifiques de répulsion entre femelles ont été hautement significatives par rapport aux témoins, à l'exception toutefois des réactions de femelle ayant copulé face à des femelles ayant elles aussi copulé. Les répulsions moyennes chez H. armigera et H. zea pour les 8 femelles de chaque expérience ont été: a) vierges en présence d'une vierge: 7,33 et 7,66; b) vierges en présence d'une femelles ayant copulé: 5,76 et 5,58; c) femelles ayant copulé en présence d'une vierge: 4,67 et 4,83. Les différences sont hautement significatives entre chaque paire de moyennes et entre chaque paire et le lot témoin; 3,17; 3,17; 3,42; 4,00 pour H. armigera; 3,17; 3,50; 2,83 et 3,75 pour H. zea. Les femelles vierges des deux espèces, H. armigera et H. zea ont présenté une réaction de répulsion en présence d'un extrait de l'abdomen de l'autre espèce; les répulsions moyennes étant respectivement 5,53 et 5,33 contre 3,83 et 3,58 pour le lot trémoin. On peut en conclure que ces répulsions doivent entraîner une tendance à la répartition uniforme.
    Notizen: Abstract An olfactometer was used to determine the effect of pheromones released by females of the bollworms Heliothis armigera (Hübner) and H. zea (Boddie) on females of the same species. Four combinations of virgin and mated females were tested for repellency of one to the other. Evidence is presented that females of the two bollworms were repelled by females of the same species. In addition, extracts of virgin female abdomens of each species repelled virgin females of the other species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300876
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  • 5
    Digitale Medien
    Digitale Medien
    Ultrastructure of differentiating preameloblasts from tooth germs of the permanent dentition ofMacaca mulatta andMacaca arctoides (1981)
    Springer
    Calcified tissue international 33 (1981), S. 603-618 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Preameloblasts ; Tooth germs ; Monkey ; Enamel ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Cytodifferentiation of inner enamel epithelium and the adjacent connective tissue from the tip of the cervical loop to the initiation of enamel elaboration in twoMacaca species was examined. Ten- to twelve-month-old specimens were fixed by perfusion and the permanent tooth buds were prepared for transmission electron microscopy. At the cervical loop proper, inner enamel epithelium cells have lobed nuclei, a paucity of cytoplasm, and wide extracellular spaces; the basal lamina facing the dental papilla is straight. With increasing distance from the tip of the cervical loop, the following changes occur gradually: (a) preameloblasts elongate from 15 to 45 µm, and their organelles, particularly mitochondria and profiles of rough endoplasmic reticulum, become more numerous; (b) extracellular spaces decrease between preameloblasts starting at the basal (infranuclear) end; (c) the basement membrane becomes convoluted and associated with aperiodic fibers; (d) preodontoblast projections penetrate the aperiodic fibers; (e) collagen fibers subjacent to the basement membrane increase in density, with particularly thick fibers paralleling the aperiodic fibers. These modifications occur within three-fourths of the distance from the tip of the cervical loop to the mineralization front. The condensation of preodontoblasts is followed immediately by predentin synthesis. Concomitantly, the basement membrane breaks down and the aperiodic fibers are engulfed by preameloblasts. Preameloblast projections penetrate junctional predentin, contact mineralized dentin, and enamel synthesis ensues. At this stage the ameloblast is 45 µm long, the nucleus is central or basal, the Golgi apparatus has migrated apically, but the Tomes' process has not yet formed. The results indicate that odontogenesis inMacaca monkeys more closely resembles human odontogenesis than does that in the murine rodents.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02409498
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  • 6
    Digitale Medien
    Digitale Medien
    Error estimates for the combinedh andp versions of the finite element method (1981)
    Springer
    Numerische Mathematik 37 (1981), S. 257-277 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary In theh-version of the finite element method, convergence is achieved by refining the mesh while keeping the degree of the elements fixed. On the other hand, thep-version keeps the mesh fixed and increases the degree of the elements. In this paper, we prove estimates showing the simultaneous dependence of the order of approximation on both the element degrees and the mesh. In addition, it is shown that a proper design of the mesh and distribution of element degrees lead to a better than polynomial rate of convergence with respect to the number of degrees of freedom, even in the presence of corner singularities. Numerical results comparing theh-version,p-version, and combinedh-p-version for a one dimensional problem are presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01398256
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  • 7
    Digitale Medien
    Digitale Medien
    Discretization by finite elements of a model parameter dependent problem (1981)
    Springer
    Numerische Mathematik 37 (1981), S. 405-421 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65 N 30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Abstract The discretization by finite elements of a model variational problem for a clamped loaded beam is studied with emphasis on the effect of the beam thickness, which appears as a parameter in the problem, on the accuracy. It is shown that the approximation achieved by a standard finite element method degenerates for thin beams. In contrast a large family of mixed finite element methods are shown to yield quasioptimal approximation independent of the thickness parameter. The most useful of these methods may be realized by replacing the integrals appearing in the stiffness matrix of the standard method by Gauss quadratures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01400318
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  • 8
    Digitale Medien
    Digitale Medien
    The contraction number of a multigrid method for solving the Poisson equation (1981)
    Springer
    Numerische Mathematik 37 (1981), S. 387-404 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N20 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary The treatment of a multigrid method in the framework of numerical analysis elucidates that regularity of the solution is not necessary for the convergence of the multigrid algorithm but only for fast convergence. For the linear equations which arise from the discretization of the Poisson equation, a convergence factor 0,5 is established independent of the shape of the domain and of the regularity of the solution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01400317
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  • 9
    Digitale Medien
    Digitale Medien
    Convergence of a penalty-finite element approximation for an obstacle problem (1981)
    Springer
    Numerische Mathematik 37 (1981), S. 105-120 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary This study establishes an error estimate for a penalty-finite element approximation of the variational inequality obtained by a class of obstacle problems. By special identification of the penalty term, we first show that the penalty solution converges to the solution of a mixed formulation of the variational inequality. The rate of convergence of the penalization is ɛ where ɛ is the penalty parameter. To obtain the error of finite element approximation, we apply the results obtained by Brezzi, Hager and Raviart for the mixed finite element method to the variational inequality.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396189
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  • 10
    Digitale Medien
    Digitale Medien
    On finite element approximation of the gradient for solution of Poisson equation (1981)
    Springer
    Numerische Mathematik 37 (1981), S. 333-337 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS (MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary A nonconforming mixed finite element method is presented for approximation of ∇w with Δw=f,w| r =0. Convergence of the order $$\left\| {\nabla w - u_h } \right\|_{0,\Omega } = \mathcal{O}(h^2 )$$ is proved, when linear finite elements are used. Only the standard regularity assumption on triangulations is needed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01400312
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  • 11
    Digitale Medien
    Digitale Medien
    The indicatrix method. II (1981)
    Springer
    Numerische Mathematik 38 (1981), S. 255-261 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS (MOS): 65N99 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary This paper extends the earlier results by the author on two-dimensional free boundary problems. The main aim consists in derivation of an optimal error bound for the approximations of the free boundary.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01397094
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  • 12
    Digitale Medien
    Digitale Medien
    A study of Rosenbrock-type methods of high order (1981)
    Springer
    Numerische Mathematik 38 (1981), S. 279-298 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65L05 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary This paper deals with the solution of nonlinear stiff ordinary differential equations. The methods derived here are of Rosenbrock-type. This has the advantage that they areA-stable (or stiffly stable) and nevertheless do not require the solution of nonlinear systems of equations. We derive methods of orders 5 and 6 which require one evaluation of the Jacobian and oneLU decomposition per step. We have written programs for these methods which use Richardson extrapolation for the step size control and give numerical results.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01397096
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  • 13
    Digitale Medien
    Digitale Medien
    A nonconforming finite element method to compute the spectrum of an operator relative to the stability of a plasma in toroidal geometry (1981)
    Springer
    Numerische Mathematik 36 (1981), S. 455-465 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N25 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary In this paper we describe a nonconforming finite element method to compute the MHD spectrum of a plasma in a toroïdal configuration. We show that this method leads to a good approximation of the spectrum.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01395958
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  • 14
    Digitale Medien
    Digitale Medien
    Finite dimensional approximation of nonlinear problems (1981)
    Springer
    Numerische Mathematik 37 (1981), S. 1-28 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS (MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary We continue here the study of a general method of approximation of nonlinear equations in a Banach space yet considered in [2]. In this paper, we give fairly general approximation results for the solutions in a neighborhood of a simple limit point. We the apply the previous analysis to the study of Galerkin approximations for a class of variationally posed nonlinear problems and to a mixed finite element method for the NavierStokes equations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396184
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  • 15
    Digitale Medien
    Digitale Medien
    Stability of explicit time discretizations for solving initial value problems (1981)
    Springer
    Numerische Mathematik 37 (1981), S. 61-91 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65L05 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary Stability regions of explicit “linear” time discretization methods for solving initial value problems are treated. If an integration method needsm function evaluations per time step, then we scale the stability region by dividing bym. We show that the scaled stability region of a method, satisfying some reasonable conditions, cannot be properly contained in the scaled stability region of another method. Bounds for the size of the stability regions for three different purposes are then given: for “general” nonlinear ordinary differential systems, for systems obtained from parabolic problems and for systems obtained from hyperbolic problems. We also show how these bounds can be approached by high order methods.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396187
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  • 16
    Digitale Medien
    Digitale Medien
    A penalty method for the approximate solution of stationary Maxwell equations (1981)
    Springer
    Numerische Mathematik 36 (1981), S. 389-403 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N 30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary The paper deals with nonconforming finite element methods for the approximate solution of the interior boundary value problem for Maxwell equations in the time-harmonic case. The methods are based on penalization in the boundary conditions of total reflexion. Qualitative convergence results are obtained by a-priori estimates which are proven in the first part of this paper. The main object is to establish estimates for the global discretization error in various norms of the underlying spaces of approximating vector fields.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01395954
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  • 17
    Digitale Medien
    Digitale Medien
    Zero-stability properties of the three-ordinate variable stepsize variable formula methods (1981)
    Springer
    Numerische Mathematik 37 (1981), S. 157-166 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65L07 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary Consider the systemy′=f(x,y),y(a)=η,x∈[a,b],y∈R n wheref is continuous and Lipschitzian with respect to the second argument. Very often linear multistep variable stepsize variable formula methods (LM VSVFM's) are used to computey k≈y(xk) on the points of the grid:a=x 0〈x1〈x2〈...〈xN=b. The general LM VSVFM is based on formulae of the following type $$y_k = \sum\limits_{i = 1}^{s_k } {\alpha _i (\bar h_k ,sk)y_{k - i} } + \sum\limits_{i = 0}^{s_k } {h_{k - i} \beta _i (\bar h_k ,s_k )f(x_{k - i} ,y_{k - i} )} $$ whereh k=xk−xk−1, $$\bar h_k = (h_k ,h_{k - 1} , \ldots ,h_{k - s_k } )$$ ,s k≦k, k=1(1)N. The coefficients α i and β i depend on the lasts k+1 stepsizes and on the formula used at stepk. Only the zero-stability properties of some special classes of LM VSVFM's (as for example those based on Adams formulae) were investigated in the literature. A class of three-ordinate LM VSVFM's is defined in this paper. Some results concerning the zero-stability properties of these methods are proved. It is shown that some well-known results are simple corollaries of the results found for the three-ordinate LM VSVFM's. It is easily seen that similar results hold for the corresponding one-leg VSVFM's. Finally, the use of the theoretical results in the practical implementations is briefly discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01398250
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  • 18
    Digitale Medien
    Digitale Medien
    Numerical treatment of delay differential equations by Hermite Interpolation (1981)
    Springer
    Numerische Mathematik 37 (1981), S. 235-255 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65L05 ; 65Q05 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary A class of numerical methods for the treatment of delay differential equations is developed. These methods are based on the wellknown Runge-Kutta-Fehlberg methods. The retarded argument is approximated by an appropriate multipoint Hermite Interpolation. The inherent jump discontinuities in the various derivatives of the solution are considered automatically. Problems with piecewise continuous right-hand side and initial function are treated too. Real-life problems are used for the numerical test and a comparison with other methods published in literature.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01398255
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  • 19
    Digitale Medien
    Digitale Medien
    High orderP-stable formulae for the numerical integration of periodic initial value problems (1981)
    Springer
    Numerische Mathematik 37 (1981), S. 355-370 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65L05 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary Recently there has been considerable interest in the approximate numerical integration of the special initial value problemy″=f(x, y) for cases where it is known in advance that the required solution is periodic. The well known class of Störmer-Cowell methods with stepnumber greater than 2 exhibit orbital instability and so are often unsuitable for the integration of such problems. An appropriate stability requirement for the numerical integration of periodic problems is that ofP-stability. However Lambert and Watson have shown that aP-stable linear multistep method cannot have an order of accuracy greater than 2. In the present paper a class of 2-step methods of Runge-Kutta type is discussed for the numerical solution of periodic initial value problems.P-stable formulae with orders up to 6 are derived and these are shown to compare favourably with existing methods.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01400315
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  • 20
    Digitale Medien
    Digitale Medien
    Ultrastructural events and kinetics of microcyst germination in the myxomycete Didymium iridis (1981)
    Springer
    Archives of microbiology 128 (1981), S. 384-389 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Didymium iridis ; Microcyst ; Excystment ; Germination ; Ultrastructure ; Mycetozoa ; Myxomycetes ; Myxamoeba
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Microcysts of the myxomycete Didymium iridis were induced to excyst by transfer to 5mM potassium phosphate buffer. After 1 h in suspension, 90% of the microcysts had germinated into myxamoebae distinguishable by phase contrast microscopy and staining with Lugol's iodine. Both pH and osmolarity affected the kinetics of excystment. The rate and extent of excystment were decreased by cycloheximide but remained unaffected by actinomycin D, suggesting a requirement for protein synthesis but not RNA synthesis. Initially, the outer wall layers separated from the inner layer, which gradually expanded and loosened. The protoplast rehydrated and reverted to a vegetative morphology. Excysting cells were characterized by nucleolar inclusions, changes in the nuclear envelope and plasma membrane, appearance of ringed cisternal elements and microbodies in the cytoplasm, and formation of a densely fibrous zone adjacent to the site of emergence. Excysting populations have been classified into characteristic stages: mature, initiated, swollen, and pre-emergent microcysts.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00405917
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  • 21
    Digitale Medien
    Digitale Medien
    The effects of nitrogen limitation on the ultrastructure of the cyanobacterium Agmenellum quadruplicatum (1981)
    Springer
    Archives of microbiology 130 (1981), S. 204-212 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Agmenellum quadruplicatum ; Nitrogen starvation ; Ultrastructure ; PATO poststain ; Cyanobacteria
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The effects of nitrogen limitation on the ultrastructure of the unicellular cyanobacterium, Agmenellum quadruplicatum, were studied by thin sectioning transmission electron microscopy. Nitrogen became limiting for growth 14–15 h after transfer to nitrogen-limiting medium, but cultures retained full viability for at least 45 h. The c-phycocyanin: chlorophyll a ratio and cellular nitrogen content of the culture dropped rapidly after 14–15 h, as a progressive deterioration of major cell structures took place. Phycobilisomes were degraded first, followed by ribosomes and, then, thylakoid membranes. These structures were virtually depleted from the cells within 26 h. Intracellular polysaccharide accumulated in place of the normal cell structures throughout this period. Nitrogen limitation did not affect polyphosphate bodies, carboxysomes, lipid granules, the cell envelope, or the extra-cellular glycocalyx. All of the ultrastructural changes resulting from nitrogen limitation were reversed upon addition of nitrate to a starved culture. Most cell structures were restored within 3 h, and restoration was complete within 9 h.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00459520
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  • 22
    Digitale Medien
    Digitale Medien
    Arthrobacter P 1, a fast growing versatile methylotroph with amine oxidase as a key enzyme in the metabolism of methylated amines (1981)
    Springer
    Archives of microbiology 129 (1981), S. 72-80 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Arthrobacter ; Facultative methylotroph ; Amine oxidase ; Catalase ; RuMP cycle of formaldehyde fixation ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A facultative methylotrophic bacterium was isolated from enrichment cultures containing methylamine as the sole carbon source. It was tentatively identified as an Arthrobacter species. Extracts of cells grown on methylamine or ethylamine contained high levels of amine oxidase (E.C. 1.4.3.) activity. Glucose- or choline-grown cells lacked this enzyme. Oxidation of primary amines by the enzyme resulted in the formation of H2O2; as a consequence high levels of catalase were present in methylamine-and ethylamine-grown cells. The significance of catalase in vivo was demonstrated by addition of 20 mM aminotriazole (a catalase inhibitor) to exponentially growing cells. This completely blocked growth on methylamine whereas growth on glucose was hardly affected. Cytochemical studies showed that methylamine-dependent H2O2 production mainly occurred on invaginations of the cytoplasmic membrane. Assimilation of formaldehyde which is generated during methylamine oxidation was by the FBP variant of the RuMP cycle of formaldehyde fixation. The absence of NAD-dependent formaldehyde and formate dehydrogenases indicated the operation of a non-linear oxidation sequence for formal-dehyde via hexulose phosphate synthase. Enzyme profiles of the organism grown on various substrates suggested that the synthesis of amine oxidase, catalase and the enzymes of the RuMP cycle is not under coordinate control.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00417184
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  • 23
    Digitale Medien
    Digitale Medien
    Baldcypress allelochemics and the inhibition of silkworm enteric microorganisms Some Ecological Considerations (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 103-114 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Baldcypress ; Taxodium distichum ; 2-furaldehyde ; 2-furoic acid ; Bombyx mori ; Lepidoptera ; Bombycidae ; enteric microbial inhibition ; Bacillus ; Micrococcus ; Arthrobacter ; Mucor ; Curvularia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Exposure ofBombyx mori larvae to 2-furaldehyde, a major volatile component of baldcypress heartwood,Taxodium distichum, resulted in in vivo inhibition of enteric microorganisms at concentrations (1–47 ppm) that were released naturally from heartwood. The 7 bacterial and 2 fungal enteric isolates were also inhibited in vitro at the same concentrations. It is suggested that inhibition of leaf surface micro-organisms or in vivo inhibition of silkworm enteric microflora, as a result of indirect or direct action of 2-furaldehyde, exacerbates the growth-inhibitory effects of this compound on larvae by reducing the microbial nutritional contribution. The ecological significance of insect enteric microbial inhibition by plant allelochemics is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00988638
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  • 24
    Digitale Medien
    Digitale Medien
    Attractant lures for males of the pea moth,Cydia nigricana (F.) Containing (E)-10-dodecen-1-yl acetate and (E,E)-8,10-dodecadien-1-yl acetate (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 563-573 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Pea moth ; Cydia nigricana (F.) ; Lepidoptera ; Olethreutidae ; sex attractant ; (E)-10-dodecen-1-yl acetate ; (E,E)-8 ; 10-dodecadien-1-yl acetate ; lure ; formulation ; antioxidant ; monitoring
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Lures containing different amounts of (E)-10-dodecen-1-yl acetate and (E,E)-8, 10-dodecadien-1-yl acetate were formulated in natural rubber stoppers or polyethylene vials and tested in traps in the field to establish relative attractiveness to males of the pea moth,Cydia nigricana (F.), dose-response relationships, and the effects of weathering. Initially, both formulations of (E,E)-8,10-dodecadien-1-yl acetate were much more attractive than those of (E)-10-dodecen-1-yl acetate, but their activity diminished considerably after only 5 days in the field because an inhibitor was formed, and polyethylene formulations were not attractive after one week. However, lures containing (E)-10-dodecen-1-yl acetate, with or without antioxidants, in both rubber and polyethylene were still attractive after three months' exposure in the field and are therefore suitable for practical monitoring of pea moth populations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987704
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  • 25
    Digitale Medien
    Digitale Medien
    Air permeation tests with (Z,Z)-3,13-octadecadien-1-ol acetate for reduction in trap catch of peachtree and lesser peachtree borer moths (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 575-582 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Peachtree borer ; lesser peachtree borer ; Synanthedon exitiosa ; S. pictipes ; Lepidoptera ; Sessiidae ; Z,Z-3 ; 13-octadecadien-1-ol acetate sex pheromone ; traps ; air permeation ; trap catch reduction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Air permeation trials were conducted to determine whether trap catches of the peachtree borer (PTB)Synanthedon exitiosa (Say) and lesser peachtree borer (LPTB)S. pictipes (Grote and Robinson) could be reduced through application of the synthetic pheromone of the PTB, (Z,Z)-3,13-octadecadien-1-ol acetate (Z,Z-ODDA), at 92% isomeric purity. The pheromone was released into the air of peach orchard test plots with hanging laminated plastic dispensers or hollow fiber dispensers in the trees and by aerial dispersal of microcapsules containing a solution of the lure. Results showed that all formulations ofZ, Z-ODDA reduced trap catches of both PTB and LPTB in treated plots relative to catches in traps in untreated plots. In one air permeation experiment, three types of laminated dispensers and one type of hollow fiber dispenser each reduced trap catch of PTB by 93–100% and of LPTB by 75–95%. In a separate test, two formulations of microencapsulatedZ,Z-ODDA did not reduce trap catch of male PTB as effectively as the laminated dispenser; results for LPTB were similar for both the dispensers and microcapsules. Catches of male PTB moths in traps baited with laminated and or fiber pheromone dispensers containing ODDA (94∶6%Z,Z∶E,Z) were not significantly different. LPTB male moths were also captured in these traps, the catches being dependent upon the initial pheromone loading and the type of dispensers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987705
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  • 26
    Digitale Medien
    Digitale Medien
    Insect sex pheromones: Evaporation rates of alcohols and acetates from natural rubber septa (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 627-633 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Insect sex pheromones ; insect sex attractants ; Lepidoptera ; pheromones ; pheromone formulations ; insect population monitoring
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The half-lives (t 1/2) of alcohol sex pheromones, 1-alkanols, acetate sex pheromones, and an epoxide (disparlure) were determined on natural rubber septa. Thet 1/2 values for the homologous alcohols from decanol to heptadecanol increased regularly from 2.2 to 1117 days, but thet 1/2 of octadecanol was 609 days. Thet 1/2 values of (Z)7-, (E)7-, and (Z)9-tetradecen-1-ol acetates were 154, 168, and 199 days, respectively, whereas those of five other tested 14-carbon acetates ranged from 310 to 350 days. The dependence oft 1/2 values on chain length and double-bond position is consistent with the hypothesis that molecular size is an important variable affectingt 1/2 values. Also, in accordance with the hypothesis, when aZ-alkenyl compound has a much shortert 1/2 than the corresponding saturated compound, thet 1/2 values of theZ compound and itsE isomer may be quite different. Thus, (E)-9-tetradecen-l-ol acetate had at 1/2 of 331 days. Thet 1/2 of disparlure was 180 days. The effect of thecis-7,8 epoxide group is apparently similar to that of the olefin group in lowering thet 1/2 below the value that would be expected solely on the basis of chain length.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987710
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  • 27
    Digitale Medien
    Digitale Medien
    Relative efficiency of sticky and cylindrical electrical grid traps in capturingSpodoptera exigua (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 733-740 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Beet armyworm ; Spodoptera exigua ; Lepidoptera ; Noctuidae ; pheromone trap ; trap efficiency ; Pherocon 1C trap ; population monitoring
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The relative efficiency of sticky traps and cylindrical electrical grid traps for capturing male beet armyworm moths,Spodoptera exigua (Hubner), was studied using night vision equipment. The sticky and grid traps captured 34 and 40%, respectively, of the insects which oriented to them. The grid trap's capacity was limited only by the size of the receptacle (3.8-liter bucket) at the base of the funnel. The maximum capacity of the sticky trap was ca. 110 insects, and the efficiency of this trap declined rapidly when captures exceeded 50% capacity. This decline was caused by the physical blockage of the sticky surface by the captured insects. There was no evidence to indicate that captured males had any repelling effect on other males subsequently attracted to the sticky trap.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00990305
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  • 28
    Digitale Medien
    Digitale Medien
    Kairomones and their use for management of entomophagous insects (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 909-917 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Trichogramma pretiosum ; Hymenoptera ; Trichogrammatidae ; biological control ; kairomone ; Heliothis zea ; Lepidoptera ; Noctuidae ; host density
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Trichogramma pretiosum Riley females exhibit success-motivated searching after oviposition. The stimulatory effect of contact with host eggs makes host-egg density an important factor in determining the appropriate strategy for behavioral manipulation, using kairomones, that simulate host seeking, in biological control programs. Host eggs can be used, in conjunction with kairomones or by themselves, to improve the performance of these important beneficial insects.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987616
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  • 29
    Digitale Medien
    Digitale Medien
    The pineal gland of nocturnal mammals (1981)
    Springer
    Cell & tissue research 216 (1981), S. 253-271 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pinealocytes ; Cell populations ; Bat ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the pineal gland of the pipistrelle bat two different populations of pinealocytes and glial cells were observed electron microscopically. The pinealocytes of populations I and II differ in their content of metabolically active cell organelles. In the pinealocytes of population I, granular vesicles originating from the Golgi apparatus were found in the perikaryon and especially in the endings of the pinealocyte processes. Granular vesicles appeared to be more numerous in hibernating nulliparous females. The pinealocytes of population II are characterized by the presence of small cytoplasmic vacuoles, probably originating from cisternae of the granular endoplasmic reticulum and containing flocculent material of moderate electron density. The classification of the pinealocytes belonging to population II is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233619
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  • 30
    Digitale Medien
    Digitale Medien
    The fine structure of the compound eye of the African armyworm moth, Spodoptera exempta walk. (Lepidoptera, Noctuidae) (1981)
    Springer
    Cell & tissue research 216 (1981), S. 333-347 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Insect eye ; Retina ; Ultrastructure ; Moth ; Spodoptera exempta
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The morphology of the compound eye of the noctuid moth Spodoptera exempta was investigated by electron microscopy. This eucone superposition eye is composed of about 8000 ommatidia. Each ommatidium is surrounded by six secondary pigment cells showing pigment movement according to the state of adaptation. It contains four crystalline cone cells forming together a crystalline cone and tract, two primary pigment cells, which encompass the crystalline cone, and usually eight retinula cells. On the basis of their rhabdomeric structure, three types of retinula cells can be distinguished. According to the structure of the rhabdom, two types of ommatidia are found in different regions of the eye. The rhabdom of the lobed type, providing more than 80% of ommatidia, is composed of V-shaped rhabdomeres with fanwise arranged microvilli. The rhabdom of the square type, found in a small area in the dorsal region of the eye, consists of triangular rhabdomeres with parallel microvilli. The functional significance of this difference is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233623
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  • 31
    Digitale Medien
    Digitale Medien
    Rhythmic contractions of the ampullar epidermis during metamorphosis of the ascidian Molgula occidentalis (1981)
    Springer
    Cell & tissue research 216 (1981), S. 293-312 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Ascidians ; Metamorphosis ; Attachment organs ; Ultrastructure ; Rhythmic contractions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ampullae of Molgula occidentalis are hollow, tubular extensions of the epidermis. They are ensheathed by a secreted tunic. When they grow out shortly after settlement, the ampullae spread the tunic over the substratum to form a firm attachment for the sessile juvenile. A simple squamous epithelium forms the thin ampullar walls. A glandular, simple columnar epithelium forms the distal tip of each ampulla. The glandular cells probably secrete the adhesive that attaches the tunic to the substratum. Repetitive, peristaltic contractions pass from the base to the distal end of each ampulla. Microsurgery, time-lapse cinemicrography and TEM have been used to analyze this phenomenon. The contractions are mediated by a layer of 4–8 nm microfilaments in the base of the ampullar epithelium. Each juvenile has 7–9 ampullae which contract at different frequencies. Isolated ampullae continue to contract normally for several days. Thus each ampulla has an intrinsic rhythm. Microsurgical experiments suggest that there is no specific region within an ampulla with unique pacemaker properties. It is proposed that communication via gap junctions allows the coordination of ampullar cells into a well organized peristaltic wave.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233621
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  • 32
    Digitale Medien
    Digitale Medien
    Secretory granules of B-cells in the synovial membrane (1981)
    Springer
    Cell & tissue research 216 (1981), S. 131-141 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Synovial membrane ; Secretory granules ; Ultrastructure ; Cytochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Ultrastructural and cytochemical studies have been made on secretory granules of B-cells (fibroblast-like cells) in the knee-joint synovium. The secretory granules were membrane-bounded spherical or slightly elongated bodies, 150 to 350 nm (average 230 nm) in diameter and had a homogenous matrix with several cores. These granules were found in B-cells of all animal species examined; they were numerous in mice and rats, and few in guinea pigs, rabbits and man. Ultrastructural and cytochemical examinations revealed that the Golgi apparatus was involved in the formation of the secretory granules. Unlike lysosomes, they showed no acid phosphatase activity. The granule matrix was positively stained by Thiéiy's periodic acid-thiocarbohydrazidesilver proteinate technique, and the cores were digested by protease. These findings suggest that the granule matrix contains mucopolysaccharide(s) and/or glycoprotein(s) and the core material is largely proteinaceous in nature.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234549
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  • 33
    Digitale Medien
    Digitale Medien
    Effects of norepinephrine and dibutyryl adenosine 3′, 5′-cyclic monophosphate on the ultrastructure of pineal cells in monolayer culture (1981)
    Springer
    Cell & tissue research 216 (1981), S. 181-191 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pineal gland ; Monolayer culture ; N-acetyl transferase ; Ultrastructure ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary To determine how neural influences control the function of the pineal gland, morphological and biochemical relationships after pharmacological treatment have been studied in rat pineal cells in monolayer cultures. Norepinephrine (NE) and dibutyryl cyclic 3′,5′-adenosine monophosphate (dBcAMP) treatment of cells that had been in culture for 5 and 21 days produced a stimulation in the enzyme activity of serotonin N-acetyl transferase, an enzyme important in indole synthesis. NE and dBcAMP also produced morphological changes which were dependent on the time of cells in culture. When 5 day-cultures were treated with NE and dBcAMP, light and dark cells were noted and endoplasmic reticulum increased and became more organized. Only dBcAMP treatment at 5 days produced an increase in dense granules and an elongation of cytoplasmic processes. Treatment of 21 day-cultures with dBcAMP also produced an increase in cytoplasmic processes while treatment with NE produced an increase in the synaptic ribbons and clear vesicles within the processes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234553
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  • 34
    Digitale Medien
    Digitale Medien
    Role of estrogen and androgen in maintaining the preovulatory follicle (1981)
    Springer
    Cell & tissue research 216 (1981), S. 615-624 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Rat ; Preovulatory follicle ; Ultrastructure ; Estrogen ; Androgen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effects of Nitromifene citrate (CI 628), an antiestrogen, and Flutamide, an antiandrogen, on the ultrastructure and viability of the preovulatory follicle and granulosa cells were examined both in vivo and in vitro. In vivo administration of either antihormone induced degeneration within the granulosa cells. In some of the affected granulosa cells, the nuclear material was condensed while the cytoplasm and associated organelles were unaltered. In others, the density of the cytoplasm was reduced, the smooth endoplasmic reticulum was dilated but the nucleus remained unaltered. In vitro, either antihormone reduced granulosa-cell viability but the granulosa cells were twenty times more sensitive to CI 628 than to Flutamide. In addition, exposure to CI 628 induced nuclear condensation without affecting the cytoplasm, while Flutamide induced the deterioration of the cytoplasm without altering the nucleus. These observations suggest that: (1) both estrogen and androgens control the viability of the granulosa cells and thereby the follicle, (2) the action of estrogen and androgen is mediated through receptors within the granulosa cells since these antihormones prevent the nuclear uptake of their respective hormone, (3) the granulosa cells of preovulatory follicles appear to be more dependent on estrogen than on androgen, and (4) each steroid appears to have a specific role in maintaining the granulosa cell; estrogens control the integrity of the nucleus while androgens preserve the cytoplasmic organization of the granulosa cell.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238656
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  • 35
    Digitale Medien
    Digitale Medien
    The morphology of the horseshoe crab (Limulus polyphemus) visual system (1981)
    Springer
    Cell & tissue research 216 (1981), S. 655-659 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Eye ; Neuroeffector junction ; Octopamine ; Circadian rhythm ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Efferent fibers to the compound eye of the horseshoe crab, Limulus polyphemus, not only innervate the various pigment cells, but also invade the eccentric cell dendrite and the retinula cells. This finding provides a structural basis for the coupling of circadian rhythm between the efferents and the receptor cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238660
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  • 36
    Digitale Medien
    Digitale Medien
    Electron-microscopic studies on reaggregate cultures of vascular smooth muscle cells from normotensive and spontaneously hypertensive rats (1981)
    Springer
    Cell & tissue research 217 (1981), S. 225-243 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Vascular smooth muscle ; Spontaneously hypertensive rat ; Reaggregate cultures ; Ultrastructure ; Collagen synthesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Vascular smooth muscle cells were taken from the aortae of the WKY (normotensive) and SHR (spontaneously hypertensive) strains of rat by enzymatic dispersion and put into reaggregate culture. Initially the cells became individual spheroids having average diameters of 10 μm and surfaces that were either rough or smooth. The cells were far more complex than they appeared on their surfaces; after one day in culture, there was considerable internal variation in these cells. All the cells, whether WKY or SHR, lost the bulk of their cytoplasmic contents (including myofilaments, many mitochondria, and vesicular structures) in the early stages of culture and eventually became flattened. After 14 days in culture, these modified cells collected to form reaggregates that were commonly roughly spherical and several hundred μm in diameter. These reaggregates consisted of peripheral regions made up of several layers of flattened cells overlying cores formed by glia-like networks of cells similar in cytological appearance to the cells at the periphery. The meshes formed in this way contained cellular debris derived from dead cells or extrusion of cellular contents. It appears that SHR cells are quicker to form reaggregates than are WKY cells. Yet the SHR cells retained a rounded conformation after five days, whereas the WKY cells were more flattened and formed a more discrete aggregate at this stage of culture. However, by the fourteenth day of culture, differences between the two cell strains were not so pronounced, as far as could be judged by observations made with scanning and transmission electron microscopy. Both WKY and SHR cells at 14 days appeared highly secretory, possessing large Golgi systems as well as numerous ER cisternae and mitochondria. SHR cells produced greater amounts of connective tissue at all stages of culture than did WKY cells, indicating that a similar difference may contribute to the hypertension which develops naturally in situ in SHR animals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233577
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  • 37
    Digitale Medien
    Digitale Medien
    Ultrastructural study of electrophysiologically identified neurones in the paraventricular nucleus of the rat (1981)
    Springer
    Cell & tissue research 216 (1981), S. 503-512 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Paraventricular neurones ; Alcian-blue labelling ; Ultrastructure ; Electrophysiology ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructural characterization of electrophysiologically identified neurones of the rat paraventricular hypothalamic nucleus was performed with extracellular labelling technique. The extracellularly recorded neurones are labelled with an electrophoretic deposit of alcian blue contained in the recording micropipette. The neurone thus labelled takes on a dark and shrunken appearance which enables its detection among neighbouring cells without, however, concealing its main morphological characteristics. 1) Spontaneously firing neurones, invaded by an antidromic action potential elicited by electrical stimulation of the neurohypophysis, were identified as magnocellular cells containing dense-cored vesicles of 200–250 nm in diameter. Dense-cored vesicles were not found in the antidromically activated neurones devoid of spontaneous activity. 2) Trans-synaptically activated neurones in the PVN or in its dorso-lateral edge were small cells devoid of dense secretory vesicles. 3) PV neurones in which neurohypophysial stimulation evoked no response, contained small, dense vesicles (100 nm in diameter) comparable with those found in parvocellular peptidergic neurones.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238647
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  • 38
    Digitale Medien
    Digitale Medien
    Pore canals in the cornea of a functionally specialized area of the honey bee's compound eye (1981)
    Springer
    Cell & tissue research 216 (1981), S. 491-501 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Ultrastructure ; Cornea ; Compound eye ; Honey bee (Apis mellifera)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fine structure of the cornea in an anatomically and functionally specialized part of the honey bee's compound eye (dorsal rim area) was examined by light microscopy, transmission electron and scanning electron microscopy. Under incident illumination the cornea appears grey and cloudy, leaving only the centers of the corneal lenses clear. This is due to numerous pore canals that penetrate the cornea from the inside, ending a few μm below the outer surface. They consist of (1) a small cylindrical cellular evagination of a pigment cell (proximal), and (2) a rugged-walled, pinetree-shaped extracellular part (distal). The functional significance of these pore canals is discussed. It is concluded that their light scattering properties cause the wide visual fields of the photoreceptor cells measured electrophysiologically in the dorsal rim area, and that this is related to the way this eye region detects polarization in skylight.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238646
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  • 39
    Digitale Medien
    Digitale Medien
    The sensillum capitulum, an antennal hygro- and thermoreceptive sensillum of the cockroach, Periplaneta americana L. (1981)
    Springer
    Cell & tissue research 216 (1981), S. 525-543 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Hygroreceptor ; Thermoreceptor ; Sensillum capitulum ; Cockroach ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The sensillum capitulum, a hygro- and thermoreceptive sensillum of the cockroach Periplaneta americana L. is comprised of four receptor cells, one glial cell, two gland cells and four enveloping cells. Each receptor cell sends a single axon to the CNS, and has a single dendrite which extends distally. The perikarya of three receptor cells are enclosed by one of the enveloping cells (number one) and the fourth by a gland cell. The dendrites of all four receptor cells are enclosed by the same enveloping cell. The dendrites contain rootlets and many microtubules. The sensory cilia arise at the end of the dendrites at the level of the inner cavity, expand from the connecting cilium in a manner similar to those of the amphinematic scolopidia, and have numerous microtubules. The 1st enveloping cell contains scolopale rod-like structures. The sensory cilia are surrounded distally by a cuticular sheath formed within the 1st enveloping cell. One of the sensory cilia disappears distally, and the remaining ones enter the sensillum cone. Of these, one branches and the other two do not. The distal ends of the unbranched cilia are differentiated into tubular structures. The sensillum cone is comprised of an inner stem and a guard wall, neither of which is perforated. The outer cavity is enclosed by the 2nd, 3rd, and 4th enveloping cells, and distally in the antenna is closely apposed to the cuticular wall. This cavity contains lipid deposits. These structural features are discussed with regard to the mechanism of hygroreception in P. americana.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238649
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  • 40
    Digitale Medien
    Digitale Medien
    Stereological studies on the small intestinal epithelium of the rat (1981)
    Springer
    Cell & tissue research 217 (1981), S. 11-21 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Intestinal mucosa ; Small intestinal epithelium ; Ultrastructure ; Duodenum ; Jejunum ; Stereology ; Rats
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Quantitative macroscopic, light-microscopic and electron-microscopic studies were performed on the small intestine of fasted and non-fasted adult, male Sprague-Dawley rats. In non-fasted rats the small intestine was longer than in fasted rats. Due to the presence of villi the surface area in the duodenum and the jejunum was enlarged about six times. The microvilli on the villous crests caused a surface enlargement by 13 times in the duodenum (value corrected for overestimation due to section thickness), and 19 times in the jejunum of the fasted rats. At the base of the villi these values were about 50% lower. It was calculated that, in the fasted rats, the total enlargement of the luminal surface area — due to villi and microvilli — was 63 times in the duodenum and 81 times in the jejunum (corrected for section thickness). Differences between the villous crest epithelium and the villous base epithelium were also found with regard to the mean cell height, and the volume densities of the absorptive cell nuclei, the mitochondria, and the paracellular channels.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233821
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  • 41
    Digitale Medien
    Digitale Medien
    Biosystematic studies onCapsella bursa-pastoris (Brassicaceae): Enzyme polymorphism in natural populations (1981)
    Springer
    Plant systematics and evolution 137 (1981), S. 73-94 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Brassicaceae ; Capsella bursa-pastoris ; Isoenzyme polymorphism ; population analyses ; geographic variation ; heterozygosity ; breeding system
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The genetic variability of natural populations ofCapsella bursapastoris in North- and Middle-Europe has been estimated by means of enzyme assays. Zymograms of 81 populations have been developed. 17 loci could be identified, and 8 of them can be heterozygous. Genetic variability is greater between populations than within. No correlation between actual population sizes and genetic heterogeneity could be detected. Some electromorphs shift their frequencies proportionally to increasing adversity of climatic conditions, some appear to be constant over the whole area, and others are characterized by an apparently irregular variation pattern. Marginal populations comprise a significantly higher proportion of heterozygous plants than central ones. Apart from this clinal variation pattern, a mosaic pattern, strongly related to habitat conditions, was observed: genetic heterogeneity is greater in more intensively disturbed sites. The pattern of genetic variation in natural populations ofCapsella bursa-pastoris is rather highly influenced by the breeding system.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00983207
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  • 42
    Digitale Medien
    Digitale Medien
    The breeding system ofEmblingia (Emblingiaceae) (1981)
    Springer
    Plant systematics and evolution 137 (1981), S. 63-65 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Emblingia ; Emblingiaceae ; Sapindaceae ; Dodonaea ; Stylobasidaceae ; Stylobasium ; Gyrostemonaceae ; Anemophily ; entomophily ; autogamy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Emblingia is a short lived fire weed with a highly autogamous breeding system.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00983205
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  • 43
    Digitale Medien
    Digitale Medien
    Vergleichende cytotaxonomische Untersuchungen anRanunculus seguieri und der Artengruppe desR. alpestris (Ranunculaceae) (1981)
    Springer
    Plant systematics and evolution 138 (1981), S. 47-60 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Ranunculaceae ; Ranunculus seguieri ; R. alpestris ; R. traunfellneri ; R. bilobus ; R. crenatus ; Relationship betweenR. seguieri andR. alpestris s. lat.: morphology ; crossing experiments ; chromosome numbers ; karyotypes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Morphological and cytological investigations as well as crossing experiments were carried out withRanunculus seguieri Vill. and 4 species of theRanunculus alpestris L. group (R. alpestris L.,R. traunfellneri Hoppe,R. bilobus Bertol.,R. crenatus Waldst. & Kit.). ForR. seguieri andR. alpestris, localities and distribution are given in addition to extensive diagnoses. A key to the species includes morphological characteristics and distribution data forR. traunfellneri, R. bilobus, andR. crenatus. New diagnostic characters are described. Crossing experiments betweenR. seguieri and the species of theR. alpestris group were unsuccessful. All 5 species have a chromosome number of 2n = 16, the record forR. bilobus is new. There is no statistically significant difference between the karyotypes ofR. seguieri andR. alpestris s. str. Nevertheless, according to morphological evidence and crossing experiments,R. seguieri is not closely related to theR. alpestris group.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00984608
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  • 44
    Digitale Medien
    Digitale Medien
    A chemotaxonomical study of someBoraginaceae: pyrrolizidine alkaloids and phenolic compounds (1981)
    Springer
    Plant systematics and evolution 137 (1981), S. 127-134 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Boraginaceae ; Pyrrolizidine alkaloids ; phenolic compounds ; chemotaxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract By means of thin layer chromatography pyrrolizidine alkaloids and phenolic compounds in some members of the familyBoraginaceae, subfamiliesHeliotropioideae andBoraginoideae, were studied. FromOmphalodes verna a main alkaloid was isolated with an isoretronecanol (or stereoisomeric) nucleus. The chemotaxonomical model ofTétényi forBoraginaceae based on fatty acids is generally supported, but relationships betweenHeliotropioideae andCynoglosseae appear to be closer, suggesting parallel developments from common ancesters.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00983210
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  • 45
    Digitale Medien
    Digitale Medien
    Embryology ofEriocaulon setaceum (Eriocaulaceae) (1981)
    Springer
    Plant systematics and evolution 138 (1981), S. 175-188 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Eriocaulaceae ; Eriocaulon setaceum ; Embryology ; systematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Eriocaulon setaceum can be characterized by: young microsporangium wall with epidermis, endothecium (with fibrous thickenings), and glandular tapetum (uninucleate cells); pollen grains 3-celled, spiraperturate; embryo sac development according to the Polygonum type and with antipodal cyst; endosperm nuclear; embryo small, with incipient differentiation into cotyledonary and epicotylary loci; seed coat mainly from the inner layers of the integuments; pericarp 2-layered and membranous. Embryologically, theEriocaulaceae are nearer to theXyridaceae than to otherFarinosae. Their elevation to the rank of an order,Eriocaulales, therefore appears justified.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00985181
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  • 46
    Digitale Medien
    Digitale Medien
    Microgeographic edaphic differentiation in allozyme polymorphisms of wild barley (Hordeum spontaneum, Poaceae) (1981)
    Springer
    Plant systematics and evolution 138 (1981), S. 287-292 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Poaceae ; Hordeum spontaneum ; Allozymes ; microgeographic differentiation ; population genetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Allozymic variation in proteins encoded by 22 loci was analyzed electrophoretically in 278 individual plants of wild barley,Hordeum spontaneum, the progenitor of cultivated barley, in four 100 meter transects, in Israel, each equally subdivided into basalt and terra rossa soil types. Significant differentiation according to soil was found in 9 alleles. Our results suggest that allozyme polymorphisms in wild barley are at least partly adaptive, and differentiate by edaphic natural selection rather than by stochastic processes, and/or neutrality of allozymic variants.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00985193
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  • 47
    Digitale Medien
    Digitale Medien
    Genetic variation inSolanum pennellii: Comparisons with two other sympatric tomato species (1981)
    Springer
    Plant systematics and evolution 139 (1981), S. 11-45 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Solanaceae ; Lycopersicon ; Solanum pennellii ; Allozymes ; electrophoresis ; isozymes ; mating systems ; self-incompatibility
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Genetic variation—primarily in 19 genetic loci of seven enzyme systems—was analyzed in accessions from various parts of the geographic range ofSolanum pennellii, which according to all tested biosystematic criteria behaves like a species ofLycopersicon. In comparison with the largely sympatricL. hirsutum andL. pimpinellifolium, this species exhibits the same trends of reduced allogamy and decreased genetic variation toward the north and south margins of its distribution, though to a much lesser degree; it does not exhibit their trends toward smaller flower size in the same peripheral regions. All three species agree to a considerable extent in the ranking of their tested loci in respect to degree of variablility; however, overall polymorphy is highest inS. pennellii. Except for the appearance of self-compatibility at its southernmost margin,S. pennellii is exclusively and rigidly self-incompatible. Alleles are distributed much more uniformly over the range than in the previously mentioned species, marginal and internal endemic mutants being much less abundant. A marked geographic disagreement is evident in regions of high and low variation. These differences in patterns of genetic variability are reconciled in terms of observed differences in mating systems, probable age of distributions, and adaptive strategies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00983920
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  • 48
    Digitale Medien
    Digitale Medien
    Eine neueTillandsia-Art aus Südmexico:T. kolbii (Bromeliaceae) (1981)
    Springer
    Plant systematics and evolution 138 (1981), S. 259-262 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Bromeliaceae ; Tillandsia subgen.Allardtia ; T. kolbii ; spec. nova ; Flora of Mexico
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new species ofTillandsia is described and discussed in regard to related species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00985189
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  • 49
    Digitale Medien
    Digitale Medien
    Ultrastructure of the stylar canal cells ofCitrus limon (Rutaceae) (1981)
    Springer
    Plant systematics and evolution 138 (1981), S. 263-274 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Rutaceae ; Citrus limon ; Style ; canal cells ; canal filling substance ; ultrastructure ; anatomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The ultrastructure of the canal cells and the canal filling substance ofCitrus limon have been studied. At maturity the canal cells are very rich in cytoplasm. Their inner tangential walls lining the canal are much thickened and formed by two layers: the outer corresponds to the original wall, the inner is formed by subsequent deposition of abundant materials of different origin. This thickening occurs at the same time as the filling of the stylar canal. Both events are paralleled by considerable dictyosomic activity, the formation of a large amount of rough endoplasmic reticulum, and the incorporation of small cytoplasmic masses into the cell wall, due to plasmalemma evaginations. — The material in the stylar canal has a heterogeneous ultrastructure aspect and consists of polysaccharides, proteins and lipids; it presumably provides nutrients for the growing pollen tubes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00985190
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  • 50
    Digitale Medien
    Digitale Medien
    Resistenzphysiologische Grundlagen der evolutiven Kälteakklimatisation von Sproßpflanzen (1981)
    Springer
    Plant systematics and evolution 137 (1981), S. 145-180 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Coniferophytina ; Angiosperms ; Arecaceae ; Poaceae ; Quercus ; Citrus ; sclerophyllous trees ; mountain plants ; Acclimatation ; chilling resistance ; frost resistance ; stress ecotypes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Gradations in cold resistance of plants with different latitudinal and altitudinal distribution, and the various categories of chilling and freezing resistance are hypothesized to be evolutionary steps of adaptive responses to increasing low temperature stress and annual seasonality. The gradual lowering of the critical phase transition temperature of biomembrane lipids, the capacity of persistent supercooling of tissues, and the development of a dormancy linked freezing-tolerance are considered to be essential mechanisms resulting in improved acclimatation to low temperature climates.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00989871
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  • 51
    Digitale Medien
    Digitale Medien
    Differentiation of Fraction 1 protein in relation to age and distribution of Angiosperm groups (1981)
    Springer
    Plant systematics and evolution 138 (1981), S. 89-113 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Nicotiana ; Gossypium ; Lemnaceae ; Fraction 1 protein ; differentiation and age of taxa ; migration to Australia ; land connections ; long distance dispersal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Fraction 1 protein (F-1-protein) (ribulose bisphosphate carboxy-lase-oxygenase) contained inLemnaceae has been evolving for at least 50 million years because fossils of these plants have been identified in strata belonging to the Upper Cretaceous. Electrofocusing F-1-protein resolves the large subunit polypeptides coded by extranuclear DNA and the small subunit polypeptides coded by nuclear DNA. Four differences affecting isoelectric points of the large subunit polypeptides and eight affecting the small subunit polypeptides are now present among eleven species representing the four genera comprising theLemnaceae. In comparison, four differences in the large and 13 in the small subunit polypeptides exist among 63 species ofNicotiana; four differences in the large and eight differences in the small subunit polypeptides exist among 19 species ofGossypium. The number of differences in F-1-protein composition being of the same order of magnitude for the generaNicotiana, Gossypium, and the familyLemnaceae, we infer that these Angiosperms are of similar antiquity. Nicotiana species indigenous to Australia and Africa contain F-1-proteins whose large subunit polypeptides are different but some of whose small subunit polypeptides are like those found in species from the Western Hemisphere. The same situation is found for the F-1-protein inGossypium. These results are in harmony with the view that species ofNicotiana andGossypium have arrived in Australia via former land connections between S. America, Antarctica, and Australia.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00984611
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  • 52
    Digitale Medien
    Digitale Medien
    The tubular exine ofLauraceae andHernandiaceae, a novel type of exine structure in seed plants (1981)
    Springer
    Plant systematics and evolution 138 (1981), S. 139-146 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Magnoliidae ; Lauraceae ; Hernandiaceae ; Pollen morphology ; pollen ultrastructure ; Angiosperm phylogeny
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The pollen grains ofLauraceae andHernandiaceae are characteristic in having a tubular exine of ± microfibrillar structure. This is coated with a layer of medium electron-dense globules and very peculiar spines, made up of a substance differing from that of the exine. Such a pollen wall structure is otherwise unknown in seed plants and thus adds to the list of odd features erratically present in various taxa of the Ranalean complex.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00984614
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  • 53
    Digitale Medien
    Digitale Medien
    Effect of allopolyploidy on the activity of selected enzymes inHibiscus (1981)
    Springer
    Plant systematics and evolution 138 (1981), S. 189-198 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Malvaceae ; Hibiscus acetosella ; H. asper ; H. surattensis ; H. radiatus ; andH. cannabinus ; Allopolyploidy ; evolution of dosage compensation ; alcohol dehydrogenase ; malate dehydrogenase ; leucine aminopeptidase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Mature seeds of diploid and tetraploidHibiscus species were analyzed for enzyme activity (alcohol dehydrogenase, malate dehydrogenase, leucine aminopeptidase), total protein content, DNA amount and dry weight. The recently formed tetraploid,H. radiatus, generally had enzyme and protein levels very similar to the sum of its progenitors, while the more ancient speciesH. acetosella had several lower levels. This difference may reflect the greater amount of timeH. acetosella has had to evolve dosage compensations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00985182
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  • 54
    Digitale Medien
    Digitale Medien
    Genetic determination of pappus part number in the annual hybridMicroseris B 87 (Asteraceae—Lactuceae) (1981)
    Springer
    Plant systematics and evolution 138 (1981), S. 235-246 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae ; Lactuceae ; Microseris ; Canalized numbers ; quantitative genetics ; evolutionary genetics ; pappus parts
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The ChileanMicroseris pygmaea has a ten-part paleaceous pappus while the CalifornianM. bigelovii has five pappus parts on each achene. Hybrids between the two species have between five and ten pappus parts with averages below 7.5. Hybrid B 87 has an F 1 average value of 6.7 pappus parts. 140 F 2 plants were raised from this hybrid, and 12 F 3 families were obtained by selfing from F 2 plants. One larger F 4 family has been raised. Pappus part number in all of these is still canalized between 5 and 10. Variation within these limits is genetically determined by a quantitatively acting polygenic system. Modeling of this system suggests that a minimum of four, but probably not many more, genes are involved. This opens the possibility of a complete genetic analysis of the system.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00985187
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  • 55
    Digitale Medien
    Digitale Medien
    Seed and fruit anatomy ofCocculus hirsutus (Menispermaceae) (1981)
    Springer
    Plant systematics and evolution 139 (1981), S. 95-102 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Menispermaceae ; Cocculus hirsutus ; Seed ; fruit ; anatomy ; affinities
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The ovules ofCocculus hirsutus are anatropous, bitegmic and, crassinucellate. The fruit is drupaceous, black purple, and laterally compressed and has a pericarp demarcated into exocarp and endocarp. The seeds are curved around the basal bodies. Testa and tegmen cells are thin-walled and unspecialized. In the ripe seed the inner epidermis of the tegmen persists, whereas the entire testa and the outer layer of the tegmen degenerate. Relationships of theMenispermaceae toRanunculaceae, Berberidaceae, andLardizabalaceae are supported.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00983924
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  • 56
    Digitale Medien
    Digitale Medien
    Der Knotenbau einigerRubiaceae (1981)
    Springer
    Plant systematics and evolution 139 (1981), S. 103-111 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Rubiaceae ; Nodal anatomy ; leaf base ; stipules
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The leaf base vascularization in most of theRubiaceae corresponds to the unilacunar pattern with one complex trace. Only some species are known to have a trilacunar nodal pattern with three traces. In the unilacunar type one pair of smaller bundles separates from the complex lacunary leaf trace laterally, each soon forking into two arms: One arm becomes a marginal vein of the petiole, the other, besides supplying the stipules, forms a ± distinct vascular “bridge” within the cortex of the nodal flanks. In theRubieae this flank bridge develops as a very distinct vascular “ring” commissure out of which the whorled leaf-like appendages are vascularized; only the opposite true leaves receive their complex trace out of the lacunes directly. Axillary branches originate only from these true leaves.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00983925
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  • 57
    Digitale Medien
    Digitale Medien
    Pre-fertilization ovule development inCapsella: ultrastructure and ultracytochemical localization of acid phosphatase in the meiocyte (1981)
    Springer
    Protoplasma 107 (1981), S. 27-45 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Acid phosphatase ; Capsella ; Female meiocyte ; Ovule ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Pre-meiotic and prophase I ovules ofCapsella bursa-pastoris (L.) Medic.(monosporic,Polygonum type of gametophyte development) were fixed routinely or incubated in a modified Gomori medium containing β-glycerophosphate as a substrate. Prior to the beginning of meiosis the potential meiocyte is ultrastructurally similar to the other cells of the nucellus and is distinguished only by its size and position. At the initiation of prophase I dramatic ultrastructural and ultracytochemical changes take place in the female meiocyte. These include the sudden appearance of cytoplasmic structures composed of single and multiple concentric cisternae, distinctive changes in plastids and mitochondria, and the blebbing of 0.3 μm double-membraned vesicles from the nuclear envelope. The concentric cisternae encapsulate portions of cytoplasm containing ribosomes, plastids, mitochondria, ER fragments and vesicles. Both single and multiple concentric cisternae localize high levels of acid phosphatase and function as autophagic vesicles (AVs) that sequester ribosomes and organelles for destruction during meiosis. Plastids stop dividing and become more spherical during prophase I. Some plastids localize acid phosphatase and many show continuities between the outer membrane and the plastid envelope and acid phosphatase-rich RER cisternae. Mitochondria appear as dense, contracted spheres or rods. Some mitochondria localize acid phosphatase but they do not show membrane confluencies with the ER. Some of the plastids and mitochondria that are segregated into the functional megaspore at meiosis II are destroyed but others apparantly survive meiosis and give rise to the plastid and mitochondrial populations of the young gametophyte (Schulz andJensen, unpublished). The lateral and end walls of the meiocyte show patches of intense aniline blue fluorescence and the chalazal end wall of the cell is perforated with large numbers of plasmodesmata.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01275605
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  • 58
    Digitale Medien
    Digitale Medien
    Ultrastructure of the sperms ofPlumbago zeylanica (1981)
    Springer
    Protoplasma 107 (1981), S. 85-107 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Male cytoplasmic inheritance ; Plumbago ; Pollen grain ; Pollen tube ; Sperm ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Male gametes ofPlumbago zeylanica were examined in pollen grains and tubes using light and electron microscopy of chemically and physically fixed tissues, and Nomarski interference microscopy of isolated, living sperm cells. Male gametes are elongate, spindleshaped cells containing a nucleus, mitochondria, ER, ribosomes, vesicles, dictyosomes, probable microfilaments, and a variable number of plastids. In mature pollen grains ofP. zeylanica, the two sperm cells are directly linked; they share a transverse cell wall with plasmodesmata and are enclosed together by the inner vegetative cell plasma membrane. One of these two sperms is also associated with the vegetative nucleus as a consistent feature of pollen grain organization. The basis of this association appears to be a long, narrow projection of the sperm cell (averaging 〈 1 μm wide and about 30 μm long) which wraps around the periphery of the vegetative nucleus and occupies embayments of that nucleus. This association is maintained throughout pollen tube growth but becomes less extensive near the completion of tube growth and is severed following tube discharge. The consistent occurrence of the sperm-vegetative nucleus association in pollen grains, tubes and isolated pollen cytoplasm suggests that the two structures may be directly connected, but attempts to visualize this type of connection were unsuccessful. Possibly, the entwining nature and extent of complementary interfaces between vegetative nucleus and sperm may have a role in stabilizing their association. Functionally, the two sperms and vegetative nucleus appear to travel as a linked unit within the pollen tube, possibly increasing the effectiveness of gamete delivery and helping to ensure nearly simultaneous transmission of sperms into the receptive megagametophyte.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01275610
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  • 59
    Digitale Medien
    Digitale Medien
    Occurrence of the suberized lamella in leaves of grasses of different photosynthetic types. I. In parenchymatous bundle sheaths and PCR (“Kranz”) sheaths (1981)
    Springer
    Protoplasma 109 (1981), S. 371-401 
    Details
    ISSN: 1615-6102
    Schlagwort(e): C4 Photosynthesis ; C4 Types ; Leaf blades ; Poaceae ; Suberized lamella ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Leaf blades of 42 grasses (Poaceae) have been examined ultrastructurally for the occurrence of a suberized lamella in walls of parenchymatous bundle sheaths and PCR (= “Kranz”) sheaths in both large and small vascular bundles. The sample includes species from a range of major grass taxa, and represents all photosynthetic types found in the grasses. Three grasses with unusual C4 leaf anatomy were also included:Alloteropsis semialata, Aristida biglandulosa, Arundinella nepalensis. The presence of a suberized lamella in PCR cell walls was perfectly correlated with photosynthetic type. All PEP-carboxykinase type and NADP-malic enzyme type C4 species examined possessed a suberized lamella in outer tangential and radial walls, but with variable presence in inner tangential walls. PCR cells of bothAlloteropsis semialata andArundinella nepalensis also possessed a suberized lamella. A lamella was totally absent from parenchymatous bundle sheath cells of the C3 species examined (5 spp.) and ofPanicum milioides, a C3-C4 intermediate. It was also absent from PCR cells of NAD-malic enzyme type C4 species (14 spp.) andAristida biglandulosa. The results are discussed in relation to the leakage of CO2 from PCR cells, and to differences between C4 types in δ13C values, chloroplast position in PCR cells, and other anatomical characteristics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01287454
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  • 60
    Digitale Medien
    Digitale Medien
    Ultrastructure of cell division and reproductive differentiation of male plants in theFlorideophyceae (Rhodophyta). Mitosis inDasya baillouviana (1981)
    Springer
    Protoplasma 106 (1981), S. 329-341 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Dasya ; Mitosis ; Rhodophyta ; Spermatangia ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Mitosis in the marine red algaDasya baillouviana (Ceramiales, Florideophyceae) was observed with the electron microscope. Most details of the process are quite similar to those observed in the other macroscopic red algae studied to date. However, some minor variations were noted. At late prophase a very small nuclear envelope protrusion (NEP) is formed at each division pole subjacent to the “nucleus associated organelle” known as the polar ring (PR) and 2–3 cisternae of perinuclear endoplasmic reticulum (PER) are commonly present during metaphase-anaphase. In contrast, in the other florideophycean algae where mitosis has been reported, a prominent NEP is present at late prophase (McDonald personal communication,Scott et al. 1980) and only a single cisterna of PER is observed. Additionally, during mid-late interphase and in mitotically-quiescent cells ofDasya, a single cisterna of smooth-surfaced ER is always juxtaposed with each PR. The possible significance of PER in theFlorideophyceae and other multinucleate organisms is discussed as well as the likely functions of spindle-associated smooth ER. It is suggested that ultrastructural features of mitosis should be useful as criteria to aid in the interpretation of the phylogeny of red algae.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01275563
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  • 61
    Digitale Medien
    Digitale Medien
    Sclerorhachis leptoclada (Asteraceae-Anthemideae), eine neue Art aus dem südlichen Khorasan (1981)
    Springer
    Plant systematics and evolution 138 (1981), S. 297-299 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Asteraceae-Anthemideae ; Sclerorhachis leptoclada Rech. f. ; spec. nova ; Flora of Iran
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A fourth species ofSclerorhachis, S. leptoclada Rech. f., has been discovered in S. Khorasan. It differs from the three known species by its tender habit, rosette leaves with few short segments, extremely reduced stem leaves, and very small heads.Sclerorhachis with its four vicarious species confined to the most arid parts of the Iranian highlands is believed to belong to the paleoxeromorphics (Rechinger 1952).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00985195
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  • 62
    Digitale Medien
    Digitale Medien
    Heterochromatin and chromosome variation in cultivated species ofTulipa subg.Eriostemones (Liliaceae) (1981)
    Springer
    Plant systematics and evolution 139 (1981), S. 47-55 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Tulipa subg.Liliaceae ; Eriostemones ; Giemsa banding ; heterochromatin ; karyosystematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The chromosomes of several cultivatedTulipa species belonging to the subg.Eriostemones were examined using conventional staining and C-banding techniques. Most of the species have lightly banded chromosomes with heterochromatin content varying from nil to about 15%. The banding patterns of several taxa are described and discussed in regard to species relationships.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00983921
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  • 63
    Digitale Medien
    Digitale Medien
    Zur systematischen Stellung der GattungProckia: Karyologie und Epidermisskulptur im Vergleich zuFlacourtia (Flacourtiaceae),Grewia (Tiliaceae) und verwandten Gattungen (1981)
    Springer
    Plant systematics and evolution 139 (1981), S. 57-76 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Flacourtiaceae:Prockia ; Flacourtia ; Idesia ; Lacistema ; Rawsonia ; Tiliaceae:Grewia ; Luhea ; Karyomorphology ; epidermis ultrastructure ; Chromosomes and systematics of tropical woody plants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Detailed analyses of karyology and leaf morphology do not support relationships betweenFlacourtiaceae andTiliaceae. In spite of different chromosome numbers,Prockia (2n = 18),Flacourtia (2n = 22) andRawsonia (2n = 22) are very similar in karyomorphology, indicating a certain karyological uniformity withinFlacourtiaceae. Lacistema (2n = ca. 62) appears more isolated. On the other hand, theTiliaceae Grewia (2n = 18) andLuhea (2n = 36) have much in common and differ remarkably from the Flacourtiaceous genera. The salicoid leaf-teeth ofProckia are also found inIdesia, but never inTiliaceae. Epidermis ultrastructure reveals certain relationships betweenProckia andFlacourtia in contrast to the strongly differingGrewia. Idesia has a rare und unique epidermis sculpture. — Basic chromosome numbers and chromosomal evolution within theFlacourtiaceae are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00983922
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  • 64
    Digitale Medien
    Digitale Medien
    Chromosome numbers and rust susceptibility as taxonomic criteria inRosaceae (1981)
    Springer
    Plant systematics and evolution 137 (1981), S. 23-38 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Rosaceae ; Uredinales ; Chromosome numbers ; rust susceptibility ; tribal classification
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract BothNeuradoideae andChrysobalanoideae seem rust-free. TheSpiraeoideae andPomoideae are heavily susceptible toGymnosporangium rusts. While thePrunoideae resemble theRosoideae in being vulnerable to attacks ofPuccinia species, they are additionally susceptible toTranzschelia andThekopsora, whereas theRosoideae are characteristically afflicted byPhragmidium.—It is suggested (a) to treat theChrysobalanoideae as a separate family (Chrysobalanaceae), (b) to transferDryas from theRosoideae-Potentilleae-Dryadinae to theRosoideae-Cercocarpeae, and (c) to divide theRosoideae into two main groups of tribes: (i) the rust-freeKerrieae andCercocarpeae with x = 9, and (ii) the rust-susceptiblePotentilleae, Ulmarieae, Roseae andSanguisorbeae with x = 7.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00983201
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  • 65
    Digitale Medien
    Digitale Medien
    The evolutionary significance of multigermicity in the genusSpinacia (Chenopodiaceae) (1981)
    Springer
    Plant systematics and evolution 137 (1981), S. 57-61 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Chenopodiaceae ; Spinacia ; S. turkestanica ; S. tetrandra ; Reproduction ; multigermicity ; seedball ; dioecy ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The presence of multigerm seedballs in the chenopodiacious genusSpinacia is noted. In the wild, colonising, and “weedy” dioecious species,S. turkestanica andS. tetrandra, the distribution of a multigerm seedball could effectively overcome the problem posed by isolation of the sexes. The hypothesis is tested assessing the extent of intra-seedball progeny hybridisations and seed production in the two wild species. The success in seed production by intra-seedball progeny crosses suggests that the distribution of such seedball progeny groups permits not only a percentage survival under isolation of these dioecious plants, but also the colonisation of areas outside that of the parent populations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00983204
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  • 66
    Digitale Medien
    Digitale Medien
    The embryology ofEpipogium roseum (Orchidaceae) (1981)
    Springer
    Plant systematics and evolution 138 (1981), S. 1-7 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Orchidaceae ; Epipogium ; E. roseum ; Microsporogenesis ; female gametophyte ; systematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Development of pollen and female gametophyte inEpipogium roseum (D. Don)Lindl. has been investigated. The embryo sac conforms to the Apinagia type. The taxonomic position ofEpipogium within the family is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00984604
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  • 67
    Digitale Medien
    Digitale Medien
    Fruit dimorphism inPhaseolus sublobatus (Fabaceae) and its evolutionary significance (1981)
    Springer
    Plant systematics and evolution 137 (1981), S. 67-72 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Leguminosae ; Fabaceae ; Phaseolus sublobatus ; Geocarpy ; amphicarpy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Populations of the annualPhaseolus sublobatus from different ecogeographical zones are genetically differentiated. In twelve populations from the western ghats (Maharashtra range) chasmogamous flowers are arranged in peduncled capitate racemes borne in leaf axils of higher nodes. One population (Poona Race S4) has additional inflorescences, also with chasmogamous flowers, on the main axis between the cotyledonary node and the ground. When the pods of these flowers ripen, the inflorescence gradually coils and, eventually, gets bury the fruits in the soil. This phenomenon is not known in any other plant.—The seed-coat patterns as revealed by SEM, and germination behaviour of both aerial and subterranean seeds are similar, and both types of seeds lack dormancy.—Heavy seed predation selection pressure is probably the principal cause for the evolution of fruit dimorphism inP. sublobatus. The origin of geocarpy in relation to fruit dimorphism and seed predation is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00983206
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  • 68
    Digitale Medien
    Digitale Medien
    Distributional patterns and an additional species of thePassiflora vitifolia complex: Amazonian species diversity due to edaphically differentiated communities (1981)
    Springer
    Plant systematics and evolution 137 (1981), S. 95-105 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Passifloraceae ; Passiflora involucrata ; stat. et comb. nov. ; Species β-diversity ; Flora of Amazonia ; Peru
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Field studies in Amazonian Peru show that thePassiflora vitifolia complex, a microcosm of many larger taxa, is concentrated in Amazonia with 4 ecologically separated species. One species is restricted to seasonally inundated forests, a second to non-inundated white sand soils, a third to non-inundated lateritic soils, and the fourth mostly to non-inundated alluvial soils. A new combination is formally proposed to recognize the white sand taxon, previously regarded as a variety, as a distinct species:P. involucrata. The importance of β-diversity in maintaining high Amazonian species diversity is emphasized.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00983208
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  • 69
    Digitale Medien
    Digitale Medien
    The flower biology ofCephalanthera longifolia (Orchidaceae)—pollen imitation and facultative floral mimicry (1981)
    Springer
    Plant systematics and evolution 137 (1981), S. 229-240 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Orchidaceae ; Cephalanthera longifolia ; Cistaceae ; Cistus salviifolius ; Hymenoptera ; Halictus ; Flower biology and ecology ; pollination ; pollen imitation ; floral mimicry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Solitary bees (Halictus sp.) were found to be the effective pollinators ofCephalanthera longifolia. In the same foraging flight the bees also visit flowers ofCistus salviifolius which has a similar colour pattern.Cephalanthera offers no reward to its pollinators, but orange papillae on its labellum successfully imitate pollen ofCistus. AsCephalanthera also attracts pollinators in the absence ofCistus, this is regarded as “facultative floral mimicry”.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00982788
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  • 70
    Digitale Medien
    Digitale Medien
    Investigations on the content of steroidal alkaloids and sapogenins withinSolanum sect.Solanum ( = sect.Morella) (Solanaceae) (1981)
    Springer
    Plant systematics and evolution 138 (1981), S. 61-71 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Solanaceae ; Solanum sect.Solanum ; Diosgenin ; tigogenin ; solasodine ; chemosystematics ; ontogenetic shift
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Plant material of 55 strains from 32 species ofSolanum sect.Solanum ( = sect.Morella) has been investigated for the content of steroidal alkaloids and sapogenins. The leaf-extracts of all species contain diosgenin resp. tigogenin or both together in considerable amount. On the contrary the characteristic steroidal alkaloid solasodine was absent in these samples. For 29 species the presence of steroidal sapogenins has been proved for the first time. In unripe fruits, however, solasodine could be detected in most of the species examined. New occurences of solasodine are reported for seven further species. These chemical results may contribute to a better comprehension of the difficult genusSolanum.—Ontogenetic studies on different organs ofS. atriplicifolium show the relationship between accumulation of steroidal compounds and plant maturity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00984609
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  • 71
    Digitale Medien
    Digitale Medien
    Tillandsia carminea — eine interessante neue Bromeliacee aus dem Orgelgebirge bei Rio de Janeiro (Brasilien) (1981)
    Springer
    Plant systematics and evolution 138 (1981), S. 293-295 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Bromeliaceae ; Tillandsia subgen.Anoplophytum ; T. carminea ; spec. nova ; Flora of Brazil
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Tillandsia carminea is a new, morphologically and ecologically distinct species, related toT. stricta Solander, which occurs in the Serra dos Orgaos near Teresopolis, Brazil. It has been taken forT. rosea Lindley, but new investigations have shown thatT. rosea is a synonym toT. stricta and thatT. carminea is a good and distinct species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00985194
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  • 72
    Digitale Medien
    Digitale Medien
    2-Furaldehyde from baldcypress (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 89-101 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Baldcypress ; Taxodium distichum ; 2-furaldehyde ; Bombyx mori ; Lepidoptera ; Bombycidae ; growth inhibition ; toxicity ; Georgia silkworm industry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract 2-Furaldehyde was growth inhibitory and toxic to larvae ofBombyx mori at concentrations as low as 1 ppm. Baldcypress,Taxodium distichum, heartwood released this volatile at concentrations in excess of these levels. The adverse effect of this chemical on silkworms may partially account for the demise of the Georgia silkworm industry (circa 1765), after the construction of a baldcypress rearing facility.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00988637
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  • 73
    Digitale Medien
    Digitale Medien
    Synthesis of sex pheromone components of the forest tent caterpillar,Malacosoma disstria (Hübner) and of the western tent caterpillar,Malacosoma californicum (Packard) (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 159-164 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Synthesis ; isomers ; 5,7-dodecadienal ; sex pheromone ; Malacosoma disstria ; Malacosoma californicum ; Lepidoptera ; Lasiocampidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract All four geometrical isomers of 5,7-dodecadien-1-ol have been stereoselectively synthesized by using Wittig condensation reactions. (5 Z,7E)-5,7-Dodecadien-1-ol and its corresponding aldehyde are components of the sex pheromone of the forest tent caterpillar. (5 E,7 Z)-5,7-Dodecadienal is a component of the pheromone of the western tent caterpillar. These compounds have been successfully tested in the field.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00988643
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  • 74
    Digitale Medien
    Digitale Medien
    Feeding preferences of spruce budworm (Choristoneura fumiferana Clem.) larvae to some host-plant chemicals (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 391-402 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Choristoneura fumiferana ; Lepidoptera ; Tortricidae ; Abies balsamea ; feeding stimulants ; feeding deterrents ; feeding preference ; sugars ; glycosides ; amino acids ; organic acids
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Single-choice and three-choice tests were used to determine the relative importance of host-plant chemical extracts in eliciting feeding by spruce bud worm larvae. Water-soluble components of the host trees are the most important and, of these, the sugar and glycoside fractions are the most stimulating. The amino acid and organic base fractions have no apparent effect. The organic acid fractions deter feeding slightly.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00995761
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  • 75
    Digitale Medien
    Digitale Medien
    A four-component pheromone blend for optimum attraction of redbacked cutworm males,Euxoa ochrogaster (Guenée) (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 615-625 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Redbacked cutworm ; Euxoa ochrogaster ; Lepidoptera ; Noctuidae ; sex pheromone blend ; sex attractant ; parapheromone ; Z-5-decenyl acetate ; Z-5-undecenyl acetate ; Z-5-dodecenyl acetate ; Z-7-dodecenyl acetate ; Z-9-dodecenyl acetate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Four acetates,Z-5-decenyl acetate,Z-5-,Z-7-, andZ-9-dodecenyl acetates, in microgram ratios of 1∶200∶2∶1 or 1∶200∶6∶2 were excellent, specific sex pheromone blends for capturing male redbacked cutworm moths in cone traps. Blends in ratios of 1∶200∶2∶1 and 2∶200∶2∶1 at 1000 μg/ rubber septum dispenser remained highly effective for 6 weeks under field conditions. The essential minor components,Z-5-decenyl,Z-7-, andZ-9-dodecenyl acetates, became inhibitory at concentrations of about 10% in the blends, and this may be an important general phenomenon in lepidopteran pheromones. Blends involving a parapheromone,Z-5-undecenyl acetate, withZ-5-,Z-7-, andZ-9-dodecenyl acetate, in microgram ratios of 8∶200∶2∶1 or 20∶200∶6∶2 were also excellent specific attractants for this species. TheZ-8-dodecenyl acetate had no obvious effect on the attraction of the redbacked cutworm males.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987709
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  • 76
    Digitale Medien
    Digitale Medien
    Kairomones and their use for management of entomophagous insects: X. Laboratory studies on manipulation of host-finding behavior ofTrichogramma pretiosum riley1 with a kairomone extracted fromHeliothis zea (boddie) moth scales (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 635-648 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Kairomone ; parasitoids ; biological control ; Trichogramma pretiosum ; Hymenoptera ; Trichogramma tidae ; Heliothis zea ; Lepidoptera ; Noeturidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The behavioral response ofTrichogramma pretiosum Riley females to the kairomone found inHeliothis zea (Boddie) moth scales is examined.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987711
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  • 77
    Digitale Medien
    Digitale Medien
    Sex pheromone of the saltmarsh caterpillar moth,Estigmene acrea (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 655-668 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Saltmarsh caterpillar moth ; Estigmene acrea ; (Z,Z)-9,12-octadecadienal ; (Z,Z,Z)-9,12,15-octadecatrienal ; (Z,Z)-3,6-cis-9,10-epoxy-heneicosadiene ; fall webworm moth ; Hyphantria cunea ; insect sex pheromone ; cis-9,10-epoxyheneicosane ; trans-9,10-epoxyheneicosane ; linolealde-hyde ; linolenaldehyde ; Lepidoptera ; Arctiidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Three compounds have been identified as components of the sex pheromone emitted by females of the saltmarsh caterpillar moth,Estigmene acrea (Drury). These are (Z,Z)-9,12-octadecadienal (I), (Z,Z,Z)-9,12,15-octadecatrienal (II), and (Z,Z)-3,6-cis-9,10-epoxyheneicosadiene (III). In female tip extract they were found in a ratio of 1∶6∶25, respectively, and in trapped female effluvia the ratio was 1∶6∶27, respectively. Combinations of III with either I or II elicited sustained upwind flight in a wind tunnel, but none of these compounds by themselves did so. There is evidence that the antennal acceptor site for III is chiral.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00990299
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  • 78
    Digitale Medien
    Digitale Medien
    Comparative distribution and persistence of disparlure in woodland air after aerial application of three controlled-release formulations (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 867-880 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Disparlure ; gypsy moth ; Lymantria dispar ; Lepidoptera ; Lymantriidae ; controlled release ; laminated dispensers ; hollow fibers ; microcapsules ; atmospheric permeation ; mating disruption ; air concentration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Disparlure, the gypsy moth sex pheromone, was aerially applied to three plots, using a different controlled-release formulation-gelatin microcapsules, flakes of plastic laminates, or hollow fibers-in each plot. Disparlure concentrations in air were measured intermittently over a 34-day period after application. Measurements were made at four heights above ground: 0.3,2,5, and 10m. Wind speed and air temperature were measured concurrently. Disparlure was emitted from the microcapsules and fibers at very high levels for the first day or two; thereafter, all three formulations produced gradually decreasing aerial concentrations. After 32–34 days, concentrations in all plots ranged from 1.5% to 15.5% of those on the first day, although most of the pheromone remained in the formulations. Results suggest that the effective life of all three formulations for mating disruption by atmospheric permeation would be near 30 days under the test conditions, with fibers likely to have the shortest life. Concentrations varied diurnally throughout the experiment, with highest levels generally between 1400 and 2200 hr each day. Concentrations were highest at the 10-m height with microcapsules and at the 0.3- and 10-m heights with flakes, but were similar at all heights with fibers. Biological implications of the results are presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00992384
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  • 79
    Digitale Medien
    Digitale Medien
    Analysis of field-weathered lures containing (E)-10-dodecen-1-yl acetate, a sex attractant for the pea moth,Cydia nigricana (F.) (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 1049-1056 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Pea moth ; Cydia nigricana (F.) ; Lepidoptera ; Olethreutidae ; sex attractant ; (E)-10-dodecen-1-yl acetate ; lure ; formulation ; monitoring
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Natural rubber stoppers treated with 1, 3, or 10 mg of (E)-10-dodecen-1-yl acetate, an attractant for male pea moth,Cydia nigricana (F.), were exposed in the field during the summer of 1978 and samples analyzed at intervals. The results for all three doses fitted well to first-order loss curves with half-lives of 63.5, 64.7, and 67.3 days, respectively. Thus, lures with an initial dose of 3 mg of the attractant retained approximately 1 mg after 3 months of field exposure; they should therefore maintain a constant level of attractiveness throughout this period because previous field studies showed that moths were equally responsive to fresh lures containing between 1 and 10 mg of the attractant. There was no loss of attractant during the preparation of lures or after 4 months at −15 ° C and only 13% was lost during 3 months of storage at room temperature.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987626
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  • 80
    Digitale Medien
    Digitale Medien
    Sex pheromone of the tomato looper,Plusia chalcites (ESP) (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 1081-1088 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Plusia chalcites ; Lepidoptera ; Noctuidae ; tomato looper ; sex pheromone identification ; glass WCOT capillary chromatography ; gas chromatography-mass spectrometry ; Z-7-dodencenyl acetate ; Z-9-tetra-decenyl acetate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Z-7-Dodecenyl acetate (A) andZ-9-tetradecenyl acetate (B), in a 5∶1 ratio, have been identified as sex pheromone components of femalePlusia chalcites. In addition, small amounts of dodecyl acetate, tetradecyl acetate, hexadecyl acetate, andZ-9-dodecenyl acetate have been found in the abdominal tip extracts. This is the first known Plusiinae species which utilizes a two-component primary sex pheromone system. The most effective lure found in field experiments was a mixture of 1 mg A and 0.2 mg B absorbed on rubber septa.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987630
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  • 81
    Digitale Medien
    Digitale Medien
    Larval osmeterial secretions of the swallowtails (Papilio) (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 1089-1113 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Osmeterial secretion ; Papilio larvae ; Lepidoptera ; monoterpene ; sesquiterpene ; aliphatic acid ; ester
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The larval osmeterial secretions of sixPapilio species examined displayed a remarkable qualitative change at the fourth larval ecdysis. The secretions of 4th (penultimate) instar larvae ofP. machaon, P. memnon, P. helenus, P. bianor, andP. maackii principally comprised mono- and/or sesquiterpenoids. The compounds identified from these species included α-pinene, sabinene, β-myrcene, limonene, β-phellandrene, (Z)-β-ocimene, (E)-β-ocimene, β-elemene, β-caryophyllene, (E)-β-farnesene, β-selinene, (E,E)-α-farnesene, germacrene-A, germacrene-B, caryophyllene oxide, methyl 3-hydroxy-n-butyrate, and acetic acid. In contrast, the secretion of 4th larval instar ofP. xuthus, although containing similar terpenic compounds, was accompanied by large amounts of aliphatic acids and their esters: isobutyric acid, 2-methylbutyric acid, methyl isobutyrate and methyl 2-methylbutyrate. On the other hand, the osmeterial secretions of 5th (last) instar larvae varied little in quality among the six species, and the identified compounds consisted of isobutyric acid, 2-methylbutyric acid, methyl isobutyrate, ethyl isobutyrate, methyl 2-methylbutyrate, ethyl 2-methylbutyrate, and isovaleric acid, the last of which was specific toP. bianor andP. maackii. The chemical alteration of osmeterial exudate synchronized at the final larval ecdysis with the larval morphological change (particularly in body coloration) that appears to be of defensive significance against predators.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987631
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  • 82
    Digitale Medien
    Digitale Medien
    On the persistence of disparlure in the human body (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 313-317 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Disparlure ; Lymantria dispar ; Lepidoptera ; Lymantriidae ; pheromone persistence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Response of male gypsy moths from a sparse infestation in Italy to an observer apparently contaminated with disparlure at least two years previously is reported. Other examples of pheromone contamination of people or things are also recorded.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00995754
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  • 83
    Digitale Medien
    Digitale Medien
    Comparing the effectiveness of sexual communication disruption in the oriental fruit moth (Grapholitha molesta) using different combinations and dosages of its pheromone blend (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 501-508 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Disruption of communication ; Oriental fruit moth ; Grapholitha molesta ; Lepidoptera ; Tortricidae ; sex pheromone ; sex attractant ; (Z)-8-dodecenyl acetate ; (E)-8-dodecenyl acetate ; (Z)-8-dodecen-1-ol
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The relative efficacy of disruptant blends comprised of different combinations of the Oriental fruit moth's pheromone components was determined in field tests. Disruption was evaluated by comparing male moth catch at synthetic and female-baited traps in disruptant and non-treatment areas. Three atmospheric dosages of a 8-dodecenyl acetate (93.5%Z∶6.5%E) blend, representing two successive 10-fold decreases in concentration (2.5 × 10−2 g/hectare/day to 2.5 × 10−4 g/hectare/day) were tested alone and in combination with an additional percentage of (Z)-8-dodecen-1-ol. Male moth orientation to traps was eliminated in plots exposed to the two highest binary acetate dosages. However, significantly more males were captured in synthetic-baited traps in the lowest acetate-alone treatment, indicating a diminution of disruption efficiency. In contrast, inclusion of (Z)-8-dodecen-1-ol in the disruptant blend effected essentially complete disruption of orientation at all concentrations tested. Mating success ofG. molesta pairs confined in small cages apparently was not affected by the presence of relatively high concentrations of the binary acetate and the acetate-alcohol blends. This suggests that habituation and/or adaptation of male response, at least for comparatively “close-range” behaviors, did not occur.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987698
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  • 84
    Digitale Medien
    Digitale Medien
    Seven-week persistence of an oviposition-deterrent pheromone (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 583-588 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Oviposition ; deterrent pheromone ; Pieris brassicae ; Lepidoptera ; Pieridae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Cabbage leaves sprayed with a water solution of the oviposition-deterrent pheromone ofPieris brassicae remain deterrent to ovipositing females for at least 14 days. Under laboratory conditions, the pheromone, when dried on a glass surface, retains activity for a period of at least 7 weeks. After 7 days under vacuum conditions, some pheromone is still present, indicating a low volatility and / or high stability of (an active fraction of) the pheromone. After 125 eggs are slowly rinsed with 300 ml water, they still release detectable quantities of the pheromone.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987706
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  • 85
    Digitale Medien
    Digitale Medien
    Effect of day length and light intensity on 2-tridecanone levels and resistance inLycopersicon hirsutum f.glabratum toManduca sexta (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 707-716 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Manduca sexta (L.) ; Lepidoptera ; Sphingidae ; Lycopersicon hirsutum f.glabratum ; day length ; light intensity ; 2-tridecanone ; glandular trichome ; resistance ; allelochemic
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract First instarManduca sexta (L.) larvae confined on foliage fromLycopersicon hirsutum f.glabratum (accession PI 134417) plants grown under a long-day regime exhibited greater mortality than larvae on foliage from plants grown under a short-day regime. 2-Tridecanone, a toxin important in the insect resistance of PI 134417, was significantly more abundant in the foliage of plants grown under the long-than the short-day regimes. Light intensity influenced neither 2-tridecanone levels nor the expression of resistance. The density of glandular trichomes, which secrete 2-tridecanone, was influenced by an interaction between day length and light intensity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00990303
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  • 86
    Digitale Medien
    Digitale Medien
    Growth inhibitors in tomato (Lycopersicon) to tomato fruitworm (Heliothis zea) (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 753-758 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Lycopersicon esculentum ; Lycopersicon hirsutum f. glabratum Heliothis zea ; Lepidoptera ; Noctuidae ; α-tomatine ; rutin ; chlorogenic acid ; caffeyl aldaric acid ; allelochemics ; tomato ; tomato fruitworm
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Several compounds that retard the larval growth of the tomato fruitworm,Heliothis zea (Boddie) have been isolated and identified from tomato leaves,Lycopersicon esculentum Mill. The major allelochemics are α-tomatine (I), chlorogenic acid (II), rutin (III), and a new caffeyl derivative of an aldaric acid (IV). The isolation, analyses, and toxicity of these compounds toH. zea are presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00990307
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  • 87
    Digitale Medien
    Digitale Medien
    Biological amplification for increasing electroantennogram discrimination between two female sex pheromones ofSpodoptera littoralis (Lepidoptera: Noctuidae) (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 791-798 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Spodoptera littoralis ; Lepidoptera ; Noctuidae ; electroantennogram ; biological amplification ; pheromones ; Boarmia selenaria ; Geometridae ; Matsucoccus josephi ; Homoptera ; Coccoidea
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract MaleSpodoptera littoralis stimulated by a mixture ofS. littoralis female sex pheromone with a positional isomer and by the pheromone alone, gave greatly amplified electroantennograms (EAGs) when the antennae were connected in series. The technique is described and examples are given of its use in screening extracts for EAG activity. Dose-response curves obtained with this technique are presented and discussed. Through biological amplification, EAG discrimination between the pheromones was increased.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00992378
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  • 88
    Digitale Medien
    Digitale Medien
    Alleviation of α-tomatine-induced toxicity to the parasitoid,Hyposoter exiguae, by phytosterols in the diet of the host,Heliothis zea (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 927-946 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Host-plant resistance ; α-tomatine ; sterols ; sterol esters ; Lycopersicon esculentum ; Heliothis zea ; Lepidoptera ; Noctuidae ; parasitoids ; Hyposoter exiguae ; Hymenoptera ; Ichneumonidae ; secondary compounds
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The solitary, endoparasitic ichneumonid,Hyposoter exiguae (Viereck) is a parasitoid of the tomato fruitworm,Heliothis zea (Boddie). However, the parasitoid is deleteriously affected by the tomato glycoalkaloid, α-tomatine, ingested from hosts (H. zea) fed on artificial diets or semipurified extracts of tomato plants that contained α-tomatine. α-Tomatine causes prolonged larval development; disruption or prevention of pupal eclosion; deformation of antennal, abdominal, and genital structures; and reduction in adult weight and longevity of the parasitoid. These toxic effects are exacerbated when the dietary dose of α-tomatine is increased from 12 μmol to 20 μmol/g dry wt of diet. However, the toxicity of α-tomatine is attenuated in parasitoids reared from hosts fed on artificial diets that contain equimolar or supramolar amounts of 3β-OH-sterols admixed with α-tomatine. Further, the toxicity of extracts from the foliage of different cultivars of tomatoes toH. exiguae is contingent upon the composite levels of α-tomatine and total phytosterol (free and esterified). Cultivars with a low total sterol-tomatine ratio are more toxic toH. exiguae. The possible mode of action of α-tomatine toxicity toH. exiguae by disruption of sterol metabolism is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987618
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  • 89
    Digitale Medien
    Digitale Medien
    Kairomones and their use for management of entomophagous insects (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 1057-1061 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Heliothis zea ; Lepidoptera ; Noctuidae ; Microplitis croceipes ; Hymenoptera ; Braconidae parasitoids ; kairomones
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract In laboratory experiments conducted to compare the kairomonal activity forMicroplitis croceipes (Cresson) of frass fromHeliothis zea (Boddie) larvae fed on different host plants,M. croceipes females responded to extracts of frass from larvae reared on cotton or soybeans but not on corn. The lack of response to frass from larvae reared on corn was shown to be a result of a lack of some appropriate chemical(s) in the corn.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987627
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  • 90
    Digitale Medien
    Digitale Medien
    Etude ultrastructurale de la spermatogènese chezTrichinella spiralis Owen 1835 (Nématode trichuroïde) (1981)
    Springer
    Parasitology research 64 (1981), S. 207-215 
    Details
    ISSN: 1432-1955
    Schlagwort(e): Ultrastructure ; Spermatogenesis ; Nematoda ; Trichinella spiralis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé L'étude ultrastructurale de la spermatogénèse chezT. spiralis a permis de retrouver chez cette espèce les caractères morphologiques observés dans la lignée mâle chez la plupart des Nématodes, c'est-à-dire absence de flagelle chez le spermatozoïde, absence de reconstitution de l'enveloppe nucléaire après divisions méiotiques, structure atypique du centriole. Elle a permis de situer le spermatozoïde par rapport aux classifications antérieurement proposées.
    Notizen: Abstract The ultrastructural study of spermatogenesis inT. spiralis demonstrated the main characteristics of the male germ cells in the class Nematoda, i.e. lack of flagella, lack of reconstitution of the nuclear envelope after the meiotic divisions, and atypical structure of the centriole. The spermatozoon ofT. spiralis was compared with previous classifications of the Nematoda spermatozoa.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00930498
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  • 91
    Digitale Medien
    Digitale Medien
    The ultrastructure of the epidermis of the redia ofParorchis acanthus nicoll (Digenea; Philophthalmidae) (1981)
    Springer
    Parasitology research 65 (1981), S. 19-30 
    Details
    ISSN: 1432-1955
    Schlagwort(e): Parorchis acanthus ; Redia ; Ultrastructure ; Epidermis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Regional and age differences in the epidermis of the redia ofP. acanthus have been studied by transmission electron microscopy. The depth of the outer cytoplasmic epidermis increases by four times from stage I to stage III and the microvilli double their length and branch by stage II. Electron-dense and electron-lucent membrane bound bodies are present in all stages, the latter being released onto the surface as vesicles. Multivesicular bodies appear in stage III. All are formed in one type of secretory epidermal cell body. Anterior and posterior concentric folds, of thickened outer cytoplasmic epidermis only, increase the surface area and also the diameter of the redia on contraction. In stages I and II the apical regions of the ventro-lateral processes and birth papilla, and the lattice pattern on the posterior papilla, each consisting of thickened outer cytoplasmic epidermis only, may provide rigidity and support during migration. The uniciliate sensory receptors appear to be mechanoreceptors.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00926550
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  • 92
    Digitale Medien
    Digitale Medien
    The glomerulus of a stenohaline fresh-water teleost, Carassius auratus gibelio, adapted to saline water (1981)
    Springer
    Cell & tissue research 220 (1981), S. 73-85 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Glomerulus ; Stenohaline fresh-water teleost ; Salt-water adaptation ; Kidney ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Prussian carp, Carassius auratus gibelio, were maintained in aquaria with a salinity of 15‰ for 3 months. More than 90% of the glomeruli disappeared from the tissue as a result of the adaptation to saline water. Kidney tissue was excised and prepared for electron microscopy after perfusion fixation in situ. The fine structure of the renal corpuscle was compared with the normal ultrastructure of glomeruli of control fish from fresh-water aquaria. The main alterations include retraction of the endothelium from the basement membrane, widening of the subendothelial region, folding of the thickened basement membrane and epithelial layer, and the dislocation of slit diaphragms. The findings are discussed in relation to developmental stages of mammalian glomeruli and glomeruli from tissue cultures. The structural changes of the rudimentary glomeruli of the carp kept in 15‰ salt water differ from those observed in euryhaline fish from sea water.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00209967
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  • 93
    Digitale Medien
    Digitale Medien
    Developmental stages and localization of peroxidatic activity in the leucocytes of three teleost species (Cyprinus carpio L.; Tinca tinca L.; Salmo gairdneri Richardson) (1981)
    Springer
    Cell & tissue research 220 (1981), S. 163-180 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Leucocytes ; PO-reactivity ; Teleosts (Cyprinus carpio L., Tincatinca L., Salmo gairdneri R.) ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructural localization of peroxidase (PO) in the leucocytes of three teleosts (Cyprinus carpio L., Tinca tinca L., Salmo gairdneri R.) has been investigated using the 3,3′-diaminobenzidine method. In the heterophilic granulocytes the granules show a species specific structure and are PO-positive at pH 7.6. They can be traced back to small granules arising near the Golgi apparatus (GA) in the promyelocyte. They coalesce to form larger granules and gradually change into the mature type. Myelocytes contain small unreactive granules, and these represent a second granule population. Eosinophils contain one PO-positive granule type (at pH 9), and these granules show a varying density during cell maturation. Basophils are present only in the Cyprinid species, and contain unreactive granules originating from precursors displaying a weakly positive reaction at pH 7.6. The active secretory organelles (RER, GA) are PO-negative, except for a weakly positive reaction in the flocculent matrix of the inner G-cisternae. In promonocytes and monocytes the granules are unreactive, but in the macrophages PO-positive staining occurs in a few small to medium sized granules, and in large vacuoles. At least some of these latter are apparently derived from phagolysosomes containing digested erythrocytes. Thrombocytes and lymphocytes are unreactive. The successive development of PO-positive and negative granule populations in the heterophils, and the PO-reactivity of eosinophils and basophils, show some similarities to the corresponding cells in higher vertebrates, but an analogous PO-positive (“azurophil”) granule type in monocytes seems to be absent.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00209975
    Standort Signatur Erwartet Verfügbarkeit
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  • 94
    Digitale Medien
    Digitale Medien
    Sex pheromone components isolated from china corn borer,Ostrinia furnacalis guenée (lepidoptera: Pyralidae), (E)- and (Z)-12-tetradecenyl acetates (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 841-851 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Lepidoptera ; Pyralidae ; Ostrinia furnacalis ; sex pheromone ; corn borer ; (E)-12-tetradecenyl acetate ; (Z)-12-tetradecenyl acetate ; tetradecyl acetate ; gas chromatography-mass spectrometry ; selected ion monitoring technique
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The sex pheromone components from the corn borer spreading widely in China,Ostrinia furnacalis Guenée, have been identified as (E)-and (Z)-12-tetradecenyl acetates (E andZ12–14∶ Ac). The ratio ofE isomer toZ isomer was 53 ∶ 47. Traps containing 1 × 10−7−1 × 10−5 g of these compounds captured more males than did live females or their tip extract (3–6 female equivalents). Tetradecyl acetate (14 ∶ Ac) was also identified in the tip extract. Its quantity was about 1.8 times the sum of the other two isomers. However, including this compound in its natural ratio in pheromone traps resulted in a decrease in trap catches (P〈 0.05).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00992382
    Standort Signatur Erwartet Verfügbarkeit
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  • 95
    Digitale Medien
    Digitale Medien
    Identification of a sex pheromone ofHeliothis subflexa (GN.) (Lepidoptera: Noctuidae) and field trapping studies using different blends of components (1981)
    Springer
    Journal of chemical ecology 7 (1981), S. 1011-1022 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Sex pheromone ; Heliothis subflexa ; Lepidoptera ; Noctuidae ; reproductive behavior ; field trapping ; capillary chromatography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Eight compounds were isolated from the sex pheromone gland ofHeliothis subflexa (Gn.) and identified as hexadecanal, (Z)-9-hexadecenal, (Z)-11-hexadecenal, (Z)-7-hexadecen-1-ol acetate, (Z)-9-hexadecen-1-ol acetate, (Z)-11-hexadecen-1-ol acetate, (Z)-9-hexadecen-1-ol, and (Z)-11-hexadecen-1-ol. Although the whole blend was found to be an effective male attractant, the deletion of alcohols from the blend increased trap captures considerably. Further, although the binary mixture of (Z)-9-hexadecenal and (Z)-11-hexadecenal caught some maleH. subflexa, significant increases in captures were noted when the three acetate components were included in the blend.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987623
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  • 96
    Digitale Medien
    Digitale Medien
    Ultrastructural studies on the nucleoli of the follicle cells in the Lizards Acanthodactylus scutellatus hardyi and Eremias brevirostris (1981)
    Springer
    Cell & tissue research 214 (1981), S. 169-180 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Nucleolus ; Pyriform cells ; Intermediate cells ; Lizards ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of the nuclei in the ovarian follicular cells has been examined in the lizards Acanthodacylus scutellatus hardyi, and Eremias brevirostris. During certain growth stages, the nuclei of the intermediate and the pyriform cells become large and conspicuous, and usually contain numerous morphologically variable nucleoli. The latter may be nucleolonemal, compact, ring-shaped, “filamentous”, “fine-filamentous”, “amorphous” or “course-granular” in type, and the number and type in each nucleus seems to be related to the developmental stage. The type of nucleolus may indicate different phases of activity in the nucleus and may also suggest an association with the production of different types of RNA.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00235154
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
    Digitale Medien
    Digitale Medien
    Identification and morphometric evaluation of the synapses of optic nerve afferents in the optic tectum of the axolotl (Ambystoma mexicanum) (1981)
    Springer
    Cell & tissue research 214 (1981), S. 593-611 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Synapses ; Optic afferents ; Optic tectum ; Axolotl ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The terminals of retinal afferents in the tectum of the axolotl have been identified ultrastructurally using techniques of horseradish peroxidase-filling and degeneration. The mitochondria in filled structures show a characteristic electron-lucent matrix. After both eyes have been removed, terminals with light mitochondria disappear from the area known to receive an optic input. In this area the presence of light mitochondria is almost always diagnostic of the retinal origin of a bouton. The synapses are similar to those assumed to be of retinal origin in other vertebrates. Detailed morphometric analysis has been carried out on identified optic synapses in the optic tectum of the axolotl.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233499
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Digitale Medien
    Digitale Medien
    The ultrastructure of the innervation of the intestinal wall in the teleosts Myoxocephalus scorpius and Pleuronectes platessa (1981)
    Springer
    Cell & tissue research 214 (1981), S. 651-658 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Intestine ; Teleost ; Ultrastructure ; Innervation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The innervation of the intestinal wall in the teleosts Myoxocephalus and Pleuronectes was examined electron microscopically. Two classes of axons can be identified. The first, which is in the majority, contains numerous 50–150 nm granular vesicles as well as some 40–50 nm agranular vesicles while the second contains predominantly the 40–50 nm agranular vesicles. Chromate/dichromate staining methods suggest that the first type is aminergic. Both types lie in close association with the perikarya of intrinsic myenteric neurons but only axons containing predominantly agranular vesicles have synaptic membrane specialisations. No axon bundles pass into the longitudinal muscle layer in Myoxocephalus gut and though some do in Pleuronectes, they do not closely approach the smooth muscle cells. Axons containing large granular vesicles lie in intimate contact with the myocytes of the circular muscle layer. Both axon types pass through the submucosa to form a plexus underneath the mucosal epithelium. Varicosities containing agranular or granular vesicles are separated from the epithelial cells by a gap of about 200 nm in which lies a basal lamina.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233504
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
    Digitale Medien
    Digitale Medien
    Nerves containing substance P, vasoactive intestinal polypeptide, enkephalin or somatostatin in the guinea-pig taenia coli (1981)
    Springer
    Cell & tissue research 215 (1981), S. 21-39 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Peptidergic nerves ; Guinea-pig taenia coli ; Substance P ; Vasoactive intestinal peptide ; Somatostatin ; Enkephalin ; Ultrastructure ; Histochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The guinea-pig taenia coli is rich in peptide-containing nerves. Nerve fibres containing substance P (SP), vasoactive intestinal peptide (VIP), or enkephalin, were numerous in the smooth muscle while somatostatin fibres were very few. Nerve fibres displaying SP or VIP immunoreactivity were numerous in the myenteric plexus. Enkephalin nerve fibres were fairly numerous in the plexus while somatostatin nerve fibres were sparse. Nerve cell bodies containing immunoreactive SP or VIP were regularly seen in the plexus. Delicate varicose elements of the different types of nerve fibres were found to ramify around nerve cell bodies in a manner suggestive of innervation. In the electron microscope the various peptide-storing nerve fibres (i.e., elements containing SP, VIP or enkephalin) were found to contain a varying number of fairly large, electron-opaque vesicles in the varicose swellings. These vesicles represent the storage site of the neuropeptides. The isolated taenia coli responded to electrical nerve stimulation with a contraction. After cholinergic and adrenergic blockade the contractile response was replaced by a relaxation followed by a contraction upon cessation of stimulation. SP contracted the taenia while VIP caused a relaxation. The enkephalins raised the resting tension slightly while somatostatin had no effect. These observations are compatible with a role for SP as an excitatory neurotransmitter and for VIP as an inhibitory one, and with the view that both SP neurones and VIP neurones act as motor neurones. In preparations contracted by SP the electrically induced contractions were reduced in amplitude while the electrically induced relaxations seen after adrenergic and cholinergic blockade were enhanced in amplitude. In preparations relaxed by VIP there was an increased contractile response to electrical stimulation, while in the atropine + guanethidine-treated preparation the electrically induce relaxations were reduced in amplitude. The enkephalins reduced the contractile response to electrical stimulation, while somatostatin induced a very small reduction in the amplitude of such responses. These observations suggest that SP neurones and VIP neurones may play additional roles as interneurones. Somatostatin neurones probably act as interneurones. Enkephalin-containing fibres may serve to modify the release of transmitter from other nerves in the smooth muscle, perhaps through axo-axonal arrangements. Alternatively, the enkephalin nerve fibres in the smooth muscle are afferent elements involved in mediating sensory impulses to the myenteric plexus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00236246
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  • 100
    Digitale Medien
    Digitale Medien
    Hepatocyte differentiation during early fetal development in the rat (1981)
    Springer
    Cell & tissue research 215 (1981), S. 133-142 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Rat fetus ; Hepatocyte differentiation ; Ultrastructure ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Rat hepatocyte differentiation between day 12 and 19 of fetal life was studied by electron microscopy. The cytoplasmic structures involved in synthetic and secretory function, i.e., rough endoplasmic reticulum and Golgi apparatus, appear to be the first to differentiate, and their development is probably related to the secretion of different kinds of plasma proteins. The cytoplasmic organelles involved in other hepatic functions develop later: lysosomes from day 15, peroxysomes, glycogen rosettes and smooth endoplasmic reticulum still later. However, the morphological differentiation of bile canaliculi begins from day 12.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00236254
    Standort Signatur Erwartet Verfügbarkeit
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