ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Ultrastructure  (129)
  • Lepidoptera  (59)
  • CR: 5.17
  • Seismology
  • Springer  (225)
  • D. Reidel Publishing Company  (1)
  • Division of Earthsciences, Seismological Laboratory, California Institute of Technology
  • Dover Publ.
  • North-Holland
  • 2010-2014
  • 1995-1999
  • 1980-1984  (226)
  • 1950-1954
  • 1982  (102)
  • 1981  (124)
Sammlung
Schlagwörter
Verlag/Herausgeber
Erscheinungszeitraum
  • 2010-2014
  • 1995-1999
  • 1980-1984  (226)
  • 1950-1954
Jahr
  • 1
    Digitale Medien
    Digitale Medien
    Behandlung steifer Anfangswertprobleme gewöhnlicher Differentialgleichungen mit adaptiven Runge-Kutta-Methoden (1982)
    Springer
    Computing 29 (1982), S. 153-165 
    Details
    ISSN: 1436-5057
    Schlagwort(e): 65L05 ; CR: 5.17 ; Numer. Analysis ; verallgemeinerte Runge-Kutta-Methoden ; steife Probleme
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik
    Beschreibung / Inhaltsverzeichnis: Abstract Adaptive Runge-Kutta-methods are considered. Investigations of stability for these linear implicit methods are studied. For the application a LS-stable method of order four with an adaptive stepsize control is proposed. Test results for 25 stiff initial value problems for different tolerances are discussed.
    Notizen: Zusammenfassung Es werden adaptive Runge-Kutta-Verfahren betrachtet und Stabilitätsuntersuchungen für diese linear impliziten Methoden durchgeführt. Für die Anwendung wird ein LS-stabiles Verfahren vierter Ordnung mit einer angepaßten Schrittweitenkontrolle vorgeschlagen. Testergebnisse von 25 stiff Anfangswertproblemen für verschiedenen Toleranzen werden diskutiert.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02249938
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Approximation of time-dependent free boundaries (1982)
    Springer
    Numerische Mathematik 40 (1982), S. 179-199 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS) ; Primary 65N30 ; Secondary 35R35 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary Two problems are considered in the paper: the first of them is connected with elliptic variational inequalities and consists in developing a moving obstacle algorithm for approximating the unknown free boundary; the other problem is linked with numerical solution of the Stefan problem, which is formulated in the similar way as in the elliptic case. Some computational aspects are also discussed in the paper.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01400538
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Finite elements for parabolic equations backwards in time (1982)
    Springer
    Numerische Mathematik 40 (1982), S. 207-227 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65M30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary Several regularization methods for parabolic equations backwards in time together with the usual additional constraints for their solution are considered. The error of the regularization is estimated from above and below. For a “boundary value problem in time”-method, finite elements as well as a time discretization are introduced and the error with respect to the regularized solution is estimated, thus giving an overall error of the discrete regularized problem. The algorithm is tested in simple numerical examples.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01400540
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Adams methods for neutral functional differential equations (1982)
    Springer
    Numerische Mathematik 39 (1982), S. 221-230 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65L05 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary In this paper Adams type methods for the special case of neutral functional differential equations are examined. It is shown thatk-step methods maintain orderk+1 for sufficiently small step size in a sufficiently smooth situation. However, when these methods are applied to an equation with a “non-smooth” solution the order of convergence is only one. Some computational considerations are given and numerical experiments are presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01408695
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Improvement of numerical solution of boundary layer problems by incorporation of asymptotic approximations (1982)
    Springer
    Numerische Mathematik 39 (1982), S. 309-324 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS (MOS): 65L10 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary A method for improvement of the numerical solution of differential equations by incorporation of asymptotic approximations is investigated for a class of singular perturbation problems. Uniform error estimates are derived for this method when implemented in known difference schemes and applied to linear second order O.D.E.'s. An improvement by a factor ofε n+1 can be obtained (where ɛ is the “small” parameter andn is the order of the asymptotic approximation) for a small amount of extra work. Numerical experiments are presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01407865
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Finite difference methods and their convergence for a class of singular two point boundary value problems (1982)
    Springer
    Numerische Mathematik 39 (1982), S. 341-350 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65L10 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary We discuss the construction of three-point finite difference approximations and their convergence for the class of singular two-point boundary value problems: (x α y′)′=f(x,y), y(0)=A, y(1)=B, 0〈α〈1. We first establish a certain identity, based on general (non-uniform) mesh, from which various methods can be derived. To obtain a method having order two for all α∈(0,1), we investigate three possibilities. By employing an appropriate non-uniform mesh over [0,1], we obtain a methodM 1 based on just one evaluation off. For uniform mesh we obtain two methodsM 2 andM 3 each based on three evaluations off. For α=0,M 1 andM 2 both reduce to the classical second-order method based on one evaluation off. These three methods are investigated, theirO(h 2)-convergence established and illustrated by numerical examples.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01407867
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    On the numerical analysis of the Von Karman equations: Mixed finite element approximation and continuation techniques (1982)
    Springer
    Numerische Mathematik 39 (1982), S. 371-404 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS (MOS): 65 N 30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary The purpose of this paper is to study the approximation of the Von Karman equations by the mixed finite element scheme of Miyoshi and to follow the solutions arcs at a neighbourhood of the first eigenvalue of the linearized problem. This last problem is solved by a continuation method.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01407870
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Maximale Konvergenzordnung bei der numerischen Lösung von Anfangswertproblemen mit Splines (1982)
    Springer
    Numerische Mathematik 39 (1982), S. 449-463 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS (MOS): 65L65 ; CR: 5.17 ; AMS (MOS): 65L65 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Beschreibung / Inhaltsverzeichnis: Summary In [10] a general procedureV is presented to obtain spline approximations by collocation for the solutions of initial value problems for first order ordinary differential equations. In this paper the attainable order of convergence with respect to the maximum norm is characterized in dependence of the parameters involved inV; in particular the appropriate choice of the collocation points is considered.
    Notizen: Zusammenfassung In [10] ist ein allgemeines VerfahrenV beschrieben, das die Lösungen von Anfangswertproblemen bei gewöhnlichen Differentialgleichungen erster Ordnung durch Splines approximiert. Die Konstruktion der Splines erfolgt hierbei mittels Kollokation. In dieser Arbeit wird die maximal erreichbare Konvergenzordnung vonV bezüglich der Maximumnorm in Abhängigkeit aller Parameter vonV charakterisiert, insbesondere wird auf die geeignete Wahl der Kollokationsknoten eingegangen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01407875
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Über die Effektivität einiger nichtlinearer Verfahren bei der numerischen Behandlung steifer Differentialgleichungssysteme (1982)
    Springer
    Numerische Mathematik 40 (1982), S. 169-177 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65L05 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary The stability and accuracy of some explicit nonlinear methods for the numerical integration of stiff systems of ordinary differential equations are investigated. It is shown, that in the general case they can produce the essential error. The special class of stiff systems is singled out, for which these methods are highly efficient. Some numerical results are also presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01400537
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Discretization of multiparameter eigenvalue problems (1982)
    Springer
    Numerische Mathematik 40 (1982), S. 319-328 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS (MOS): 65J05, 65L15 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary Although multiparameter eigenvalue problems, as for example Mathieu's differential equation, have been known for a long time, so far no work has been done on the numerical treatment of these problems. So in this paper we extend the spectral theory for one parameter (cf. [7, II, VII]) to multiparameter eigenvalue problmes, formulate in the framework of discrete approximation a convergent numerical treatment, establish algebraic bifurcation equations for the intersection points of the eigenvalue curves and illustrate this with some numerical examples.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396449
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 11
    Digitale Medien
    Digitale Medien
    The finite element method for parabolic equations (1982)
    Springer
    Numerische Mathematik 40 (1982), S. 373-406 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30, 65M20 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary We extend in this paper the analysis of a posteriori estimates of the space discretization error presented in a previous paper [3] for time-independent space meshes. In the context of the model problem studied there, results are given relating the effectiveness of the error estimator to properties of the solution, space meshes, and manner in which the meshes change. A procedure based upon this theory is presented for the adaptive construction of time-dependent meshes. The results of some computational experiments show that this procedure is practically very effective and suggest that it can be used to control the space discretization error in more general problems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396452
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 12
    Digitale Medien
    Digitale Medien
    An approximation technique for the numerical solution of a Stefan problem (1982)
    Springer
    Numerische Mathematik 38 (1982), S. 141-154 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 35 A 40 ; 35 K 05 ; 65 N 15 ; 65 K 05 ; 80 A 20 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary A nonlinear approximation technique for the numerical solution of certain free boundary problems is proposed. The method is shown for a degenerate one-dimensional Stefan problem. For this problem, an error estimate, which is independent of the used algorithm, is derived. Numerical examples are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01395813
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 13
    Digitale Medien
    Digitale Medien
    Travel-time residuals and three-dimensional velocity structure of Italy (1982)
    Springer
    Pure and applied geophysics 120 (1982), S. 583-606 
    Details
    ISSN: 1420-9136
    Schlagwort(e): Seismology ; P-wave residuals ; Three-dimensional velocity inversion ; Velocity structure of Italy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract Jeffreys-Bullen P and PKP travel-time residuals observed at more than 50 seismic stations distributed along Italy and surrounding areas in the time interval 1962–1979, indicate the complex velocity pattern of this region. Strong lateral velocity inhomogeneities and low velocity zones are required to explain the observed pattern of residuals. In particular, late arrivals of about 1 sec are observed in the Apenninic mountain range, requiring both greater crustal thickness and low velocity layers, coherent with seismic refraction data and surface wave dispersion measurements. The seismic stations located in the Western and Eastern Alps indicate the presence of high velocities. In the Western Alps the strong azimuthal variation of residuals and the high values of early arrivals have a close relationship to the Ivrea body, an intrusive crustal complex characterized by a velocity as high as 7–7.2 km/sec. A travel-time inversion performed with theAki et al. (1977) block model, confirms the peculiar characteristics and the sharp variations in the lithosphere of the whole Italian region, with values of velocity perturbations between many adjacent blocks, ranging in size from 50 to 100 km, and independent from the earth parametrization chosen, reaching values up to 10% in the lithospheric part and 5% in the asthenosphere. 3-D inversion requires also high velocity along the Tyrrhenian coastal margin, equivalent to an uprise of major crustal and lithospheric discontinuities along this part of the Italian peninsula. Moreover low velocity material must be present in the northern part of the Adriatic foreland, in the lithosphere-asthenosphere system, closely related to the stress and seismicity pattern, and the lateral bending of the lithosphere in the same region.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00879838
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 14
    Digitale Medien
    Digitale Medien
    On improving the absolute stability of local extrapolation (1982)
    Springer
    Numerische Mathematik 40 (1982), S. 329-337 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS (MOS): 65L05 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary A widely used technique for improving the accuracy of solutions of initial value problems in ordinary differential equations is local extrapolation. It is well known, however, that when using methods appropriate for solving stiff systems of ODES, the stability of the method can be seriously degraded if local extrapolation is employed. This is due to the fact that performing local extrapolation on a low order method is equivalent to using a higher order formula and this high order formula may not be suitable for solving stiff systems. In the present paper a general approach is proposed whereby the correction term added on in the process of local extrapolation is in a sense a rational, rather than a polynomial, function. This approach allows high order formulae with bounded growth functions to be developed. As an example we derive anA-stable rational correction algorithm based on the trapezoidal rule. This new algorithm is found to be efficient when low accuracy is requested (say a relative accuracy of about 1%) and its performance is compared with that of the more familiar Richardson extrapolation method on a large set of stiff test problems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396450
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 15
    Digitale Medien
    Digitale Medien
    The finite element method for parabolic equations (1982)
    Springer
    Numerische Mathematik 40 (1982), S. 339-371 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; 65M20 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary In this first of two papers, computable a posteriori estimates of the space discretization error in the finite element method of lines solution of parabolic equations are analyzed for time-independent space meshes. The effectiveness of the error estimator is related to conditions on the solution regularity, mesh family type, and asymptotic range for the mesh size. For clarity the results are limited to a model problem in which piecewise linear elements in one space dimension are used. The results extend straight-forwardly to systems of equations and higher order elements in one space dimension, while the higher dimensional case requires additional considerations. The theory presented here provides the basis for the analysis and adaptive construction of time-dependent space meshes, which is the subject of the second paper. Computational results show that the approach is practically very effective and suggest that it can be used for solving more general problems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396451
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 16
    Digitale Medien
    Digitale Medien
    The indicatrix method in free boundary problems (1982)
    Springer
    Numerische Mathematik 38 (1982), S. 39-52 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS (MOS): Primary 65L10 ; Secondary 35R35 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary An approximate method for nonlinear problems with functional constraints is considered, in which the constraint in the whole domain is replaced by the constraint on a manifold of lower dimension. The stability criterion is introduced, and convergence theorems are proved for the onedimensional problem. Numerical results for the elastic-plastic torsion problem are given.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01395807
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 17
    Digitale Medien
    Digitale Medien
    Existence and approximation results for nonlinear mixed problems: Application to incompressible finite elasticity (1982)
    Springer
    Numerische Mathematik 38 (1982), S. 365-382 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary This paper considers the problems of minimizing Gateaux-differentiable functionals over subsets of real Banach spaces defined by a non-linear equality constraint. The existence of a Lagrange multiplier is proved, together with approximation results on the constrained subset, provided a nonlinear compatibility condition, generalizing the classical inf-sup condition, is satisfied. These ideas are applied to equilibrium problems in incompressible finite elasticity and lead to convergence results for these problems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396438
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 18
    Digitale Medien
    Digitale Medien
    A note onC o Galerkin methods for two-point boundary problems (1982)
    Springer
    Numerische Mathematik 38 (1982), S. 447-453 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS) 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary As is known [4]. theC o Galerkin solution of a two-point boundary problem using piecewise polynomial functions, hasO(h 2k ) convergence at the knots, wherek is the degree of the finite element space. Also, it can be proved [5] that at specific interior points, the Gauss-Legendre points the gradient hasO(h k+1) convergence, instead ofO(h k ). In this note, it is proved that on any segment there arek−1 interior points where the Galerkin solution is ofO(h k+2), one order better than the global order of convergence. These points are the Lobatto points.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396444
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 19
    Digitale Medien
    Digitale Medien
    On the stability of backward differentiation methods (1982)
    Springer
    Numerische Mathematik 38 (1982), S. 467-471 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS) 65L20 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary The approximation of linear systemsy′=−A(t)y+b(t) by backward differentiation methods up to order 5 is considered. It is proved that the error does not increase if the real symmetric matrixA(t) is positive definite andA′(t) is negative semi-definite.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396446
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 20
    Digitale Medien
    Digitale Medien
    Approximation of Hopf bifurcation (1982)
    Springer
    Numerische Mathematik 39 (1982), S. 15-37 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65 N 30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary We make several assumptions on a nonlinear evolution problem, ensuring the existence of a Hopf bifurcation. Under a fairly general approximation condition, we define a discrete problem which retains the bifurcation property and we prove an error estimate between the branches of exact and approximate periodic solutions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01399309
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 21
    Digitale Medien
    Digitale Medien
    The numerical solutions of interface problems by infinite element method (1982)
    Springer
    Numerische Mathematik 39 (1982), S. 39-50 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary In this paper we derive error estimates for infinite element method used in the approximation of solutions of interface problems. Furthermore, approximations of stress intensity factors are given. The infinite element method may be considered as a certain scheme of mesh refinement, but it has the advantages that the refinement is easy to be constructed that the stiffness matrix can be calculated efficiently, and that an approximate solution which has a singularity at the singular point can be also obtained.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01399310
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 22
    Digitale Medien
    Digitale Medien
    Finite dimensional approximation of nonlinear problems (1982)
    Springer
    Numerische Mathematik 38 (1982), S. 1-30 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary In the first two papers of this series [4, 5], we have studied a general method of approximation of nonsingular solutions and simple limit points of nonlinear equations in a Banach space. We derive here general approximation results of the branches of solutions in the neighborhood of a simple bifurcation point. The abstract theory is applied to the Galerkin approximation of nonlinear variational problems and to a mixed finite element approximation of the von Kármán equations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01395805
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 23
    Digitale Medien
    Digitale Medien
    Éléments finis mixtes incompressibles pour l'équation de Stokes dans ℝ3 (1982)
    Springer
    Numerische Mathematik 39 (1982), S. 97-112 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS (MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary We introduce some new families of finite element approximation for the stationary Stokes and Navier Stokes equations in a bounded domain in ℝ3. These elements can used tetahedrons or cubes. The approximation satisfie exactly the incompressibility condition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01399314
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 24
    Digitale Medien
    Digitale Medien
    Ultrastructural localization and gradient of activity of alkaline phosphatase activity during rodent odontogenesis (1982)
    Springer
    Calcified tissue international 34 (1982), S. 273-279 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Odontogenesis ; Ultrastructure ; Alkaline phosphatase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The ultrastructural localization and gradient of activity of alkaline phosphatase were studied with respect to cell differentiation, matrix synthesis, and matrix mineralization in the incisor and molar teeth of 4-day-old Sprague-Dawley rats. The animals were perfused intracardially at room temperature with 2.5% glutaraldehyde in 0.1M sodium cacodylate (pH 7.4) with 3–4% sucrose. The jaws were dissected, immersion-fixed for 24 h, and the incisor and molar tooth germs removed. These were demineralized in 10% EDTA in NaOH (pH 7.4) with 7% sucrose. After reactivation of the enzyme with 0.1M MgCl in Tris-maleate buffer (pH 7.4) at 4°C, the teeth were incubated for alkaline phosphatase in a medium consisting of 6 ml 3% sodiumβ-glycerophosphate, 4 ml 0.2M Tris-HCl buffer (pH 9.2), 3 ml 1.6% MgSO4, 12 ml 0.5% lead citrate (pH⋍12), and 2.1 g sucrose. The pH was adjusted to 9.2 with 0.2M HCl, the volume made up to 30 ml, and the solution centrifuged for 10 min at 5000 rpm. Control teeth were incubated in medium minus the substrate. Finally, the specimens were routinely post-fixed and embedded for sectioning and examination with a Philips 300 electron microscope. A gradient of alkaline phosphatase activity was mapped along the developing teeth in the cells of the stratum intermedium, the proximal borders of the ameloblasts, the early dentine matrix, the predentine-dentine border, matrix vesicles, and the plasma membranes of odontoblasts and subodontoblast cells. The gradient of alkaline phosphatase activity was evident in the forming tooth from the cervical loop to the crown apex and was related to the cellular events, matrix synthesis, and matrix mineralization occurring during odontogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02411250
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 25
    Digitale Medien
    Digitale Medien
    Electron microscopy of avian osteopetrosis induced by retrovirus MAV.2-O (1982)
    Springer
    Calcified tissue international 34 (1982), S. 382-390 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Avian osteopetrosis ; Avian oncornavirus ; Ultrastructure ; Calcification ; Bone cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Diaphyseal tibial bone of 12.5 – 13-day and 19-day-old embryos and 20-day-old hatched chicks infected with retrovirus MAV.2-O were examined by transmission electron microscopy. The viruses were associated with lining osteoblasts and osteocytes. Whereas the infection of the osteoblast layer seemed to be a transient stage, virus association with osteocytes was a constant and main ultrastructural feature. The viruses were found either in the osteoid or in the periosteocytic space of the bone lacunae. They arose from dense cytoplasmic areas located near the cell plasmalemma via a budding process. The newly budded virus particles often had a large tail or a fine stalk-like process lost in the extracellular space. The viruses underwent calcification by deposition of inorganic material and were incorporated in the bone trabeculae. No production of virus was observed in typical osteoclasts with well-differentiated ruffled borders. The viral-induced avian osteopetrosis seemed to result from increased bone deposition through stimulation of osteoblast and osteocyte activities, whereas osteoclastic bone resorption seemed to be undisturbed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02411272
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 26
    Digitale Medien
    Digitale Medien
    Ultrastructure of the cyanobacterium,Mastigocladus laminosus (1982)
    Springer
    Archives of microbiology 133 (1982), S. 11-19 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Cyanobacteria ; Ultrastructure ; Mastigocladus laminosus ; Fischerella ; True branching
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The morphology and ultrastructure of the thermophilic cyanobacteriumMastigocladus laminosus were examined by scanning and transmission electron microscopy. Mature cultures consisted of relatively old, wide filaments that branched frequently to form younger, thinner filaments. The cells of the younger filaments had a consistently cylindrical morphology, while those of older filaments were rounded and pleomorphic. The internal ultrastructure of the cells depended somewhat on their age. As young cells became larger and wider, their thylakoids underwent slight rearrangement and spread out toward the center of the cytoplasm. Polyphosphate bodies, carboxysomes (polyhedral bodies), and lipid-body-like structures increased in number as the cells aged, but ribosomes and cyanophycin granules were depleted. Cell division involved septum formation followed by ingrowth of the outer membrane and sheath. Cells in older filaments were separated from each other by a complete layer of sheath material. Septum formation in older cells was also seen to occur parallel to the long axis of the filament, thereby confirming that true branching took place.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00943762
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 27
    Digitale Medien
    Digitale Medien
    Range of action and interaction of pheromone traps for the summerfruit tortrix moth,Adoxophyes orana (F.v.R.) (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 1251-1262 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Lepidoptera ; Tortricidae ; Adoxophyes orana ; pheromone traps ; attraction ; interaction ; trap spacing ; wind ; monitoring ; mass trapping
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract In a spindle-tree apple orchard, sex pheromone traps for the summerfruit tortrix moth were distributed at different spacings. From the captures, information was derived about influence of prevailing wind direction and of trap spacing on interactions between traps. Prevailing wind direction in the experimental area had no appreciable influence on trap interaction, perhaps because of eddying within the planting. The relationship between density and capture of traps was first considered theoretically and interaction by overlap of active-space areas was distinguished from that by overlap of mere capturing areas, which depend also on distance of dispersal. The actual results were in accordance with these considerations and indicated that the diameter of the active-space areas averaged 15 m. The variation in the captures of the wider-spaced traps was too large to be conclusive about the average width of the capturing areas, but the diameter of these seemed to be more than about 45 m. These data have been related to adequate trap distances for monitoring and mass trapping.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987758
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 28
    Digitale Medien
    Digitale Medien
    Effects of cotton condensed tannin, maysin (Corn) and pinitol (soybeans) onHeliothis zea growth and development (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 1429-1436 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Lepidoptera ; Noctuidae ; Heliothis zea ; bioassay ; host plant resistance mechanisms ; allelochemicals
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Maysin, a flavone glycoside from corn silks, inhibits ingestion, and thus growth, ofHeliothis zea (Boddie) larvae. Pinitol from soybeans inhibitedH. zea growth by the same mechanism. Despite the widely held assumption that tannins inhibit growth by inhibiting assimilation, cotton condensed tannin inhibitedH. zea growth by reducing ingestion; no evidence was found for a reduction in assimilation. Neonate larvae are shown to be much more sensitive to allelochemics than larvae that have fed on control diet before being transferred to diet containing plant allelochemics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00989100
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 29
    Digitale Medien
    Digitale Medien
    Sex pheromone chemistry of the western spruce budwormChoristoneura occidentalis Free (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 351-362 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Choristoneura occidentalis ; western spruce budworm ; Lepidoptera ; Tortricidae ; pheromone chemistry ; Choristoneura fumiferana ; capillary GC-MS ; (E/Z)-11-tetradecenal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract SCOT capillary Chromatographic and SCOT capillary chromatographic-mass spectrometic analyses of gland washes and effluvia of virgin femaleChoristoneura occidentalis Free, have been conducted with both a diapausing and nondiapausing strain of this insect. The following compounds were identified in gland washes and effluvia in both strains:E andZ11–14∶Ald,E andZ11–14∶Ac,E andZ11–14∶OH and 14∶Ald, 14∶Ac, and 14∶OH. The average aldehyde: acetate: alcohol ratio found by analysis of single glands by virgin females (nondiapausing strain) was 1∶7∶0.73. Analysis of virgin female effluvia gave this ratio as 10∶3∶8 (diapausing strain: %Z=8, 11, 15, respectively) and 10∶3∶6 (nondiapausing strain: %Z=8, 11, 12, respectively). The saturated components were generally 1–2% of theE isomer in each case. Comparisons of EAG responses of bothC. occidentalis andC. fumiferana toE11–14∶Ald,E11–14∶Ac andE11–14∶OH were made. Correlations with both laboratory and field data previously published were also made betweenC. fumiferana andC. occidentalis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987783
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 30
    Digitale Medien
    Digitale Medien
    Disruption of male spruce budworm orientation to calling females in a wind tunnel by synthetic pheromone (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 493-506 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Choristoneurafumiferana (Clem.) ; Lepidoptera ; Tortricidae ; sex pheromone ; mating disruption ; sex attraction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Male spruce budworm [Chorisloneura fumiferana (Clem.)] moths were held for 3 hr in a wind tunnel and subjected to various concentrations of background synthetic pheromone. They were then exposed to calling females and their response was recorded. The background pheromone was presented either as discrete turbulent plumes or as a uniform permeation throughout the tunnel. The numbers of males wing-fanning and flying in response to the calling females decreased as the concentration of background pheromone increased. Of the males which flew, a higher proportion progressed upwind in the discrete plumes than in the uniform permeation, an indication that structure in the pheromone cloud is necessary for upwind progression. In both discrete plumes and uniform permeation fewer males were able to locate the females (i.e., disruption was greater) as the concentration of synthetic pheromone increased, but for the same total release rates, disruption was greater when the synthetic pheromone was released in discrete plumes rather than in a uniform permeation. This implies that disruption which involves luring males to sources of synthetic pheromone is more effective than masking female plumes by uniform permeation and suggests that it is more efficient to release pheromone from a few potent sources than from numerous low-potency sources.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987797
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 31
    Digitale Medien
    Digitale Medien
    Monooxygenase activities of fat body and gut homogenates of monarch butterfly larvae,Danaus plexippus, fed four cardenolide-containing milkweeds,Asclepias spp. (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 797-805 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Monarch butterfly ; Asclepias spp. ; monooxygenase ; induction ; cardenolide ; aldrin epoxidation ; p-chloro-N-methylanilme demethylation ; Lepidoptera ; Danaidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Monarch butterfly larvae were examined for NADPH-dependent monooxygenase activities. Midgut and fat body homogenates catalyzed aldrin epoxidation andp-chloro-N-methylanilineN-demethylation at consistently low rates compared to many other lepidopteran larvae. Homogenates from larvae collected from four different milkweeds (Asclepias spp.) with quite different cardenolide contents had similar levels of activity. There were no detectable variations in activity due to season or year of collection.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00988320
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 32
    Digitale Medien
    Digitale Medien
    Structure-activity relationships in sex attractants for north American noctuid moths (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 731-754 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Alkenylcompounds ; pheromones ; chemotaxonomy ; decenyl dodecenyl ; tetradecenyl ; hexadecenyl ; trapping ; Lepidoptera ; Noctuidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Sex attractants known for 145 species of noctuid moths have many common features both as to chemical constituents and to their relationships in blends. The great majority of constituents are straight-chain (Z)-alkenols, -alkenals, or -alkenyl acetates of even carbon number (10 through 16). The unsaturation is nonterminal in odd-numbered positions (5 through 11). In effective lures, these components are blended in specific ratios and the components in a sex pheromone or sex attractant blend are structurally related by “one-change” steps. This means that any blend component differs from one or more other components by a single structural alteration, such as a change in double bond position, or a change in carbon chain length, or a change in the oxygen function. For the few multicomponent systems known in detail, the central place in the “one-change” framework is occupied by the predominant blend component. Different patterns of occurrence of lure components occur in the subfamilies Acronictinae, Noctuinae, Hadeninae, Cuculliinae, Amphipyrinae, Heliothidinae, Plusiinae, Acontiinae, and Pantheinae, and some subfamilies are as yet without known lures. Some guiding principles for elucidation of blend compositions for unstudied species are presented; these guidelines can also be used in improvement of some synthetic blends of unsatisfactory quality.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00988315
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 33
    Digitale Medien
    Digitale Medien
    Toxicity studies of analogs of 2-tridecanone, a naturally occurring toxicant from a wild tomato (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 837-842 
    Details
    ISSN: 1573-1561
    Schlagwort(e): 2-Tridecanone ; structure-activity relationships ; Lycopersicon hirsutum f.glabratum C.M. Mull ; Heliothis zea (Boddie) ; Lepidoptera ; Noctuidae ; resistance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Toxicity bioassays of the naturally occurring insecticide 2-tridecanone and a group of structural analogs against the tomato fruitworm (Heliothis zea) reveal a significant influence of chain length on toxicity of methyl ketones. This effect may be due to the differential ability of these compounds to penetrate lipid barriers and reach the active site, since a close relationship is seen between toxicity and lipophilicity. Congeners of chain lenths 15 and over are less active than predicted by this relationship, possibly due to steric effects.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00994783
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 34
    Digitale Medien
    Digitale Medien
    Evidence of an oviposition stimulant for peachtree borer (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 1125-1132 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Peachtree borer ; Synanthedon exitiosa (Say) ; Lepidoptera ; Sessiidae ; oviposition stimulant ; peach ; Prunus persica
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Peachtree borer (PTB) cocoons, peach tree bark, and a mixture of frass and gum obtained arount PTB wounds were extracted with organic solvents of increasing polarity. Female PTB moths,Synanthedon exitiosa (Say), laid the greatest number of eggs on filter paper substrates treated with acetone extracts of PTB cocoons, ethyl acetate extracts of peach tree bark and acetone extracts of frass and gum mixtures. The extracts of cocoons or frass and gum mixture were separated by liquid chromatography and thin layer chromatography.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00986983
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 35
    Digitale Medien
    Digitale Medien
    Contact stimulants fromHeliothis virescens that influence the behavior of females of the tachinid,Eucelatoria bryani (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 1183-1191 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Kairomone ; contact chemicals ; arrestant ; host seeking ; Eucelatoria bryani ; Diptera ; Tachinidae ; Heliothis ; Lepidoptera ; Noctuidae ; parasitoid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Factors acting at contact or close range affected the behavior associated with host seeking of females, but not of males, of the tachinid,Eucelatoria bryani Sabrosky. Females were arrested by components of larvae ofHeliothis virescens (F.) and by a dichloromethane extract of okra leaves. A hexane extract ofH. virescens frass and a chloroform-methanol extract ofH. virescens larvae were both active. In addition to chemicals, shape and size were involved because females were arrested by small inert objects the size ofH. virescens larvae and frass.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00990751
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 36
    Digitale Medien
    Digitale Medien
    Effects of metronidazole on growth, chloroplast structure and differentiation in gametophytes ofAnemia phyllitidis L. Sw. (1982)
    Springer
    Protoplasma 113 (1982), S. 144-149 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Anemia phyllitidis ; Chloroplast ; Gametophyte ; Metronidazole ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Metronidazole inhibits cell division in gametophytes of the fernAnemia phyllitidis without changing morphogenetic patterns. Simultaneously the sensitivity of the prothallia against gibberellins which substitute for the natural sexual pheromone “antheridiogen A”, is increased. The inhibition of cell division is accompanied by a loss of chlorophyll and by severe changes in the ultra-structure of the chloroplasts.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01282004
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 37
    Digitale Medien
    Digitale Medien
    Nuclear and nucleolar inclusions in root tip ofBrassica napus L. (1982)
    Springer
    Protoplasma 113 (1982), S. 189-192 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Brassica napus ; Membrane ; Nucleolus ; Nucleus ; Ultrastructure ; Vacuole
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Vacuole-like structures were found in the nuclei of root tip cells ofBrassica napus. The cells containing the unusual nuclear inclusions were found to be adjacent to zones of degenerating cells. Such groups of cells occurred irregularly in the meristematic regions of the young root tips. The possibility that they represent changes which have occurred in old seeds is discussed. The “vacuole-like” structures seen in the cells adjacent to the degenerating zones were bounded by a membranous layer 12 nm thick. This is thicker than most cellular membranes. The “vacuoles” frequently contained inclusions and showed similarities to protein bodies reported elsewhere. The structures are thought to represent rearrangements of cell products which may have accumulated through an imbalance of metabolism in consequence of the imminent cell degeneration.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01280906
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 38
    Digitale Medien
    Digitale Medien
    Hyphal tip ultrastructure ofAspergillus nidulans andAspergillus giganteus and possible implications of woronin bodies close to the hyphal apex of the latter species (1982)
    Springer
    Protoplasma 113 (1982), S. 209-213 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Aspergillus nidulans ; Aspergillus giganteus ; Hyphal apex ; Ultrastructure ; Woronin body
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The hyphal tip ultrastructure ofAspergillus nidulans andAspergillus giganteus indicates that their apical organization is very similar to that found in other filamentous fungi. Both species have an area immediately behind the hyphal apex free of all large organelles and containing a high concentration of vesicles. InA. giganteus only one size class of vesicle is clearly evident, with a mean diameter of 72 nm. InA. nidulans two size classes of vesicle were found, with mean diameters of 75 nm and 31 nm. A Spitzenkörper is evident inA. nidulans as an area very close to the tip containing only the smaller vesicles. InA. giganteus one or more apparently mature Woronin bodies were found within the first 1 μm of some hyphal apices. The possible significance of their presence is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01280909
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 39
    Digitale Medien
    Digitale Medien
    Ultrastructure of meiosis in the mossRhynchostegium serrulatum I. Prophasic microtubules and spindle dynamics (1982)
    Springer
    Protoplasma 110 (1982), S. 23-33 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Meiosis ; Microtubules ; Polarity ; Ultrastructure ; Mosses
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary An extensive system of microtubules develops during meiotic prophase in the mossRhynchostegium serrulatum (Hedw.)Jaeg. &Sauerb. Development of the cytoskeleton can be traced to early prophase when the nucleus is acentric and the single plastid divides into four plastids. The cytoskeletal microtubules are associated with equidistant positioning of the four plastids at the distal tetrad poles and with migration of the nucleus to a central position in the sporocyte. The cytoskeleton, which interconnects plastids and encloses the nucleus, contributes to the establishment of moss sporocyte polarity. Just prior to metaphase I evidence of the prophase cytoskeleton is lost as the bipolar metaphase I spindle develops in association with discrete polar organizers located in opposite cleavage furrows between plastids.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01314678
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 40
    Digitale Medien
    Digitale Medien
    Ultrastructural localization of polysaccharides in the motile diatomNavicula cuspidata (1982)
    Springer
    Protoplasma 113 (1982), S. 10-22 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Diatom ; Motility ; Mucopolysaccharide ; Secretion ; Staining ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Generation of movement in benthic diatoms is thought to be intimately associated with secretion at the raphe, a slit in the silica cell wall. The presence and distribution of extracellular substances and their source was investigated cytochemically by transmission electron microscopy. Extracellular material, possibly-acid mucopolysaccharide, was observed consistently within the entire length of the raphe of both valves and also as a sheath enveloping the silica frustule. Such quantities of extracellular material are absent in conventionally fixed motile diatoms. Numerous cytoplasmic vesicles, with fibrillar contents, distributed peripherally but concentrated along the raphe and at the cell poles, react strongly with a polysaccharide specific stain; their distribution in the cell and polysaccharide content suggest these may be the source of raphe and sheath material. Results support the most recent theories on the mechanism of locomotion in outline only; the details cannot be clarified. Localization procedures using alcian blue and silver staining of peroxidised sections are discussed briefly.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01283035
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 41
    Digitale Medien
    Digitale Medien
    Isolation and ultrastructural identification of membranes from the fungusGilbertella persicaria (1982)
    Springer
    Protoplasma 111 (1982), S. 87-106 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Fungi ; Gilbertella persicaria ; Membranes ; Mitochondria ; Organelle isolation ; Plasma membrane ; Ultrastructure ; Vacuoles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Methods are described for isolating and identifying subcellular membranes from walled hyphae ofGilbertella persicaria. Differences in thickness and symmetry of membranes and in contents of vesicles were used to distinguish different types of membranes. Mitochondria, vacuoles, plasma membrane, and vesicles with attached ribosomes from homogenized germlings equilibrated at the 1.2/1.4 M interface in discontinuous sucrose gradients. Accelerated flotation in centrifuged Ficol-sucrose gradients resulted in the additional separation of the mixed membranes into three fractions: one contained predominantly intact mitochondria, another was composed of vacuoles and vesicles coated with ribosomes, and a third was enriched in plasma membranes. Based upon morphometric analysis, these fractions contained 92% mitochondria, 53% vacuoles, and 89% plasma membranes, respectively. The source of vesicles coated with ribosomes was investigated since rapidly growing hyphae ofG. persicaria contained little rough endoplasmic reticulum as compared with other classes of membranes. Reconstruction from electron micrographs of mitochondrial fragmentation and vesiculation suggested that most of the ribosome-coated vesicles originated from disrupted mitochondria rather than from rough endoplasmic reticulum. The study demonstrates the utility of ultrastructural markers to identify membranesin vitro independent of, or as an adjunct to, cytochemical and biochemical markers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01282067
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 42
    Digitale Medien
    Digitale Medien
    A light and electron microscopic study of stigmas inAneilema andCommelina species (Commelinaceae) (1982)
    Springer
    Protoplasma 112 (1982), S. 26-36 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Aneilema ; Commelina ; Cytochemistry ; Evolution ; Papillae ; Pollination ; Secretion ; Stigmas ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The stigmas of species inAneilema andCommelina are trifid and comprise elongate papillae. Progressive degeneration of papular cells is observed in stigmas from open flowers and at anthesis papillae may be moribund and collapsed. Fluid emanating from the hollow style flows onto the surface through ruptures in the cuticle at the interpapillar junctions into the interstices at maturity. This secretion stains positively for protein. Stigmas are of the “wet” type. The cuticle overlying the papillar cells is ridged and at the final stages prior to flowering this cuticle becomes detached from the underlying cellulosic wall. The sub-cuticular space so formed is filled with secretion. InAneilema species detachment of cuticle is at the papillar tip and along the lateral walls. InCommelina species the anticlinal walls of adjacent papillae are strongly attached for much of their length and thus detachment of cuticle is restricted to the papillar tip. The cell wall at the tip in both genera may proliferate forming a rudimentary transfer-cell type wall. The secretion is considered to be produced by the papillar cells. It is PAS positive but fails to stain for protein and in both the light and electron microscopes appears heterogenous. Pollen attachment, hydration, germination and early tube growth are very rapid following self-pollination, the pollen tubes entering the neck of the style within ten minutes of attachment. A unique character combination involving pollen and stigmas in these genera indicates a monophyletic origin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01280212
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 43
    Digitale Medien
    Digitale Medien
    Microcyst formation in the plasmodial slime moldDidymium iridis (1982)
    Springer
    Protoplasma 112 (1982), S. 81-91 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Didymium iridis ; Microcyst-encystment ; Ultrastructure ; Differentiation ; Myxomycete
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Myxamoebae ofDidymium iridis were removed from the bacterial food source and induced to encyst by transfer to 10 mM phosphate buffer. After 24 hours of induction approximately 90% of the myxamoebae had differentiated into microcysts. The kinetics of encystment were not significantly affected by pH or osmolarity of the encystment medium. Early stages of encystment were distinguished by the appearance of autophagic vacuoles and an extracellular “slime-like” sheath. The outer wall layer, consisting of dense fibrils, was unevenly deposited after 4 hours. An electron-lucent, second wall layer appeared between 5–10 hours followed by a densely packed, third wall layer adjacent to the plasma membrane. Wall formation appeared to involve smooth-membraned vesicles of possible Golgi origin. The vesicle contents and outer wall layer reacted with the periodic acid-silver methenamine stain for polysaccharide. The density of intramembrane particles of the protoplasmic fracture face increased during encystment with a gradual formation of aggregates of particles.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01280218
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 44
    Digitale Medien
    Digitale Medien
    Tentacle contraction and ultrastructure inDiscophrya collini: The response to cations (1982)
    Springer
    Protoplasma 112 (1982), S. 92-100 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Discophrya ; Tentacle contraction ; Cations ; Calcium ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Discophrya collini is a suctorian protozoan with contractile tentacles containing a microtubule-lined canal and microfilaments. The effects of a range of cations on tentacle contraction and ultrastructure have been determined. Treatment with 80 mM CaCl2 and 95 mM MgCl2 causes contraction to 28% and 57% of the control length respectively. Re-extension takes over 4 hours in the culture medium, but CaCl2-treated tentacles are re-extended after a 5 minutes treatment with 10−2 M EDTA or 5 × 10−3 M EGTA. CuCl2 causes a significant contraction at 10−5 M (to 77%); LaCl3 at 10−4 M (to 65%); ZnCl2 at 10−2 M (to 65%), but BaCl2, CoCl2, MnCl2, NiCl2, and SrCl2 cause significant changes only at 10−1 M. The cytoplasm of CaCl2-treated cells contains two forms of membraneous structures when viewed in TEM; that of MgCl2-treated cells reveals granular areas of medium electron density. None of these features are seen in control cells. The microtubules of the tentacle canal appear to be intact upon its retraction into the cell with no change occurring in the numbers or relative positions of the microtubules. The tentacle cortex is wrinkled. It is suggested from this and previous work that tentacle contraction may be mediated by a microfilament-based mechanism, and that calcium may be involved.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01280219
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 45
    Digitale Medien
    Digitale Medien
    Cross-linking bridges associated with the microbody-lipid globule complex inChytriomyces aureus andChytriomyces hyalinus (1982)
    Springer
    Protoplasma 112 (1982), S. 181-188 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Fungus ; Zoospore ; Ultrastructure ; Membranes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Determining how the orientation and association among organelles are maintained within zoospores of theChytridiales is important to understanding the control of zoospore motility. Zoospores of the aquatic fungi,Chytriomyces aureus andC. hyalinus, contain microbody-lipid globule complexes with an elongate microbody adjacent to the portion of a lipid globule facing the cell's interior and a fenestrated cisterna (the rumposome) opposed to the surface of the lipid globule toward the plasma membrane. Mitochondria are intimately associated with the microbody. Electron microscopy of the microbody-lipid globule complex fixed in glutaraldehyde and osmium tetroxide, with or without tannic acid, reveals cross-linking bridges connecting the rumposome to the plasma membrane, to the microbody, and to microtubules of the rootlet extending from the kinetosome. It is concluded that these bridges are responsible, at least in part, for the consistent location of the microbody-lipid globule complex in the zoospore body. The possible role of the rumposome as a receptor organelle is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01284092
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 46
    Digitale Medien
    Digitale Medien
    Rapidly-secreting, cultured oat cells serve as a model system for the study of cellular exocytosis. Characterization of cells and isolated secretory vesicles (1982)
    Springer
    Protoplasma 112 (1982), S. 196-204 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Secretion ; Vesicles ; Ultrastructure ; Cultured cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Callus-derived suspension cultures of oats dramatically increase the viscosity of the culture media after one month in culture. Colorimetric assays for sugars and protein, as well as measurements of viscosity, suggest that the released material is a long-chain polysaccharide, probably a pectinaceous substance. These cells grow slowly in liquid culture, yet despite their low cell density, they are able to increase the viscosity of the media several fold within seven days after media transfer. Ultrastructural observations show that oat cells have features common to actively-secreting cells; especially evident are numerous dictyosomes with hypertrophied cisternae. Using a combination of filtering and centrifugation techniques we were able to recover large numbers of intact secretory vesicles. The interior of the vesicles stain with periodic acid-silver hexamine, and colormetric analysis of the vesicle pellet for total sugars confirms the presence of polysaccharides in this vesicle fraction. Because of the uniformity of these cells, the high rate of secretion, and the accessability of a large vesicle population, this culture system is'a useful model for studying the secretory process in plant cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01284094
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 47
    Digitale Medien
    Digitale Medien
    Site of secretion of the trail marker of the eastern tent caterpillar (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 31-39 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Malacosoma americanum ; eastern tent caterpillar ; Lepidoptera ; Lasiocampidae ; trail pheromone ; pheromone secretory site ; silk trail
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract A new site of secretion of a chemical trail marker was found on the sternum at the tip of the last abdominal segment of the larva of the eastern tent caterpillarMalacosoma americanum. Larvae marked from this site by drawing their sterna along the substrate when they extended existing trails in search of food and again when they established recruitment trails to food-finds. Differences in the quantity or quality of the marker deposited by exploring and recruiting caterpillars may account for the greater activity of the recruitment trails.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00984003
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 48
    Digitale Medien
    Digitale Medien
    Sex pheromone of fall armyworm (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 267-273 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Fall armyworm ; Spodoptera frugiperda ; Lepidoptera ; Noctuidae ; (Z)-9-dodecen-1-ol acetate ; (Z)-9-tetradecen-1-ol acetate ; pheromone ; mating behavior
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Two components of the fall armyworm,Spodoptera frugiperda (J.E. Smith), sex pheromone, (Z)-9-dodecen-1-ol acetate (DDA) and (Z)-9-tetradecen-1-ol (TDA), were tested alone and in combination to determine their effects on male sexual response and inhibition of mating in the laboratory. The threshold response for FAW males was lower for TDA than for DDA, and males responded to TDA over a wider range of dosages. Although TDA is not attractive to FAW males in the field, this compound was highly effective in reducing mating under laboratory conditions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00984022
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 49
    Digitale Medien
    Digitale Medien
    Directional flow of male scent released byPseudaletia separata walker (Lepidoptera: Noctuidae) and its repellent effect on adults and larvae of four noctuid and one phycitine moth (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 1263-1270 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Lepidoptera ; Noctuidae ; Pseudaletia separata ; male scent ; repellent pheromone ; repellent allomone ; nonspecificity ; sexual selection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Air movement around a malePseudaletia separata Walker, observed using the smoke of an incense stick during wing-fanning, showed that the air moves away from the female and backwards. Moths moved or flew away immediately when vaporized benzaldehyde was blown over their antennae in a screen cage set in a greenhouse. This repellency lacked species, sex, or individual specificity. Male scent acts as an inhibitor to conspecific males and, at the same time, to other moths if they approach the male in courtship. Inhibition of ovipositional and larval locomotory behavior by benzaldehyde was also demonstrated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987759
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 50
    Digitale Medien
    Digitale Medien
    Sex pheromone components of the turnip moth,Agrotis segetum (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 1305-1321 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Agrotis segetum ; turnip moth ; Lepidoptera ; Noctuidae ; sex pheromone ; straight-chain acetates ; single-cell recordings ; electroantennography ; behavior ; gas chromatography-mass spectrometry ; entrainment
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Analysis of female abdominal tips ofAgrotis segetum by means of GC-MS showed the presence of 13 aliphatic acetates and alcohols. (Z)-7-Dodecenyl acetate was found to be the main component in the extracts at amounts of about 1 ng/female. (Z)-9-Tetradecenyl acetate and (Z)-7-dodecenol were present to the extent of 49 and 19%, respectively, of the main component. Minor components could be identified as decyl acetate, (Z)-5-decenyl acetate, dodecyl acetate, (Z)-9-dodecenyl acetate, tetradecyl acetate, a tetradecenyl acetate, hexadecyl acetate, a hexadecenyl acetate, (Z)-5-decenol, and (Z)-9-tetradecenol. The presence and biological activity of decyl acetate, (Z)-5-decenyl acetate, and (Z)-7-dodecenyl acetate in the extracts could be detected by GC-EAD. Tested by EAG (Z)-5-decenyl acetate evoked the highest response among pheromone candidates, followed by (E)-5-decenyl acetate and (Z)-7-dodecenyl acetate. Single-cell recordings from 100 male antennal sensilla trichodea revealed receptorcells highly sensitive to (Z)-5-decenyl, (Z)-7-dodecenyl, (Z)-8-dodecenyl, and (Z)-9-tetradecenyl acetate as well as (Z)-5-decenol. The (Z)-5-decenyl, (Z)-7-dodecenyl, and (Z)-9-tetradecenyl acetate receptors were activated significantly also by female extracts. When tested in a tube olfactometer, a blend of decyl, (Z)-5-decenyl, (Z)-7-dodecenyl, and (Z)-9-tetradecenyl acetate evoked the same male response as did female glands. Tested in the field, this blend was more attractive than virgin females. Other authors previously reported many of the compounds identified in the present study. However, both quantitative and qualitative discrepancies exist among the various investigations, possibly due to the existence of geographical races.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987764
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 51
    Digitale Medien
    Digitale Medien
    Synthesis of (±)-10-methyl-1-dodecanol acetate, the chiral component of the smaller tea tortrix moth (Adoxophyes sp.), with an option for asymmetric induction (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 41-53 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Smaller tea tortrix moth ; Adoxophyes sp. ; Lepidoptera ; Tortricidae ; asymmetric induction ; 10-methyl-1-dodecanol acetate ; ester ; chirality
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract A new route to (±)-10-methyl-1-dodecanol acetate, a minor component of the smaller tea tortrix moth (Adoxophyes sp.), is described. An optional sequence that permits the generation of the chiral center with enantiomeric excesses (ee's) as high as 74% (R) or 80% (S) employing the available (S)-(−)-prolinol as a chiral auxiliary may be included. High-performance liquid chromatography of diastereomeric intermediates allows preparation of products with greater ee's.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00984004
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 52
    Digitale Medien
    Digitale Medien
    Feeding responses of eastern spruce budworm larvae to sucrose and other carbohydrates (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 233-239 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Choristoneura fumiferana ; Lepidoptera ; Tortricidae ; carbohydrates ; sucrose ; feeding preference ; behavior
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Spruce budworm larvae reared on an artificial diet were tested for preference of twelve carbohydrates over a water control. A strong preference for sucrose was seen, followed by fructose, inositol, and glucose. Male and female larvae do not differ in their responses to sucrose. The behavioral threshold for sucrose is at 10−4 to 10−3 M, with a peak response in the range of 0.01 to 0.05 M sucrose.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00984019
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 53
    Digitale Medien
    Digitale Medien
    Sex pheromone of the avocado pest,Amorbia cuneana (Walsingham) (Lepidoptera: Tortricidae) (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 255-265 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Western avocado leafroller ; Amorbia cuneana ; sex pheromone ; Tortricidae ; (E,E)- and (E,Z)-10,12-tetradecadien-1-ol acetate ; Lepidoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The major volatile components in the extract of the female sex pheromone gland ofAmorbia cuneana consisted of (E,E)- and (E,Z)-10,12-tetradecadien-1-ol acetates. The identification was based on electroantennogram bioassay of gas Chromatographic effluent from sex pheromone gland extract, relative retention times on polar and nonpolar gas chromatographic columns, chemical degradation (ozonolysis, saponification), mass spectrometry, chemical synthetic methods, and field tests. Based on mass spectrometry and retention times by capillary gas chromatography, traces of (E)-10-tetradecen-1-ol acetate and 1-tetradecanol acetate were also present in the extract. Traps baited with a combination of synthetic (E,E)- and (E,Z)-10,12-tetradecadien-1-ol acetates caught more males than did traps baited with females.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00984021
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 54
    Digitale Medien
    Digitale Medien
    Looplure efficacy and electrophysiological responses in three plusiinae species (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 1455-1462 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Efficacy ; electroantennogram ; looplure ; response threshold ; sex attractant ; trapping ; Trichoplusia ni ; Pseudoplusia includens ; Rachiplusia ou ; pheromone ; Lepidoptera ; Noctuidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Source concentration differences of (Z)-7-dodecen-1-ol acetate, or looplure, were evaluated for field trapping efficiency and electrophysiological responses with malePseudoplusia includens (Walker),Trichoplusia ni (Hubner) andRachiplusia ou (Guenné) (Lepidoptera: Noctuidae). Sticky traps baited with 1000 μg of the lure captured a significantly greater (P 〈 0.05) number of maleP. includens andT. ni than any other concentration;R. ou males were caught at a greater rate in traps baited with 100 μg of looplure, significantly more (P 〈 0.05) than with 1000 μg. Electroantennogram (EAG) studies demonstrated that antennae of maleP. includens have a lower response threshold to looplure than eitherT. ni orR. ou antennae, the latter demonstrating the highest significant threshold of response. No differences in the stimulus-response functions of the three species were detected.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00989102
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 55
    Digitale Medien
    Digitale Medien
    Sex pheromone of the fall webworm moth,Hyphantria cunea (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 383-396 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Insect sex pheromone ; fall webworm moth ; American white moth ; Hyphantria cunea ; salt march caterpillar moth ; Estigmene acrea ; Lepidoptera ; Arctiidae ; (Z,Z)-9,12-octadecadienal ; linolealdehyde ; (Z,Z,Z)-9,12,15-octadecatrienal ; linolenaldehyde ; (Z,Z)-3,6-cis-9,10-epoxyheneicosadiene
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Three compounds have been identified as sex pheromone components produced by female fall webworm moths,Hyphantria cunea (Drury). These compounds 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). The ratio of these compounds was approximately 5∶6∶13, respectively, in female tip extracts prepared from U.S.S.R, insects and approximately 1∶8∶21, respectively, in extracts from U.S. insects. The ratio in female effluvia trapped from U.S. insects was 1∶6∶27, respectively. Compound III plus either I or II is effective in eliciting upwind flight in a wind tunnel. Compounds I, II, and III are also components of the sex pheromone system of the saltmarsh caterpillar moth,Estigmene acrea (Drury).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987787
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 56
    Digitale Medien
    Digitale Medien
    Compounds modifying the activity of two sex attractants for males of the pea moth,Cydia nigricana (F.) (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 397-408 
    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 ; inhibitor ; Synergist ; lure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract (E)-10-Dodecen-1-yl acetate (E10–12∶Ac) and (E,E)-8,10-dodecadien-1-ylacetate (E,E8,10–12∶Ac) are sex attractants for males of the pea moth,Cydia nigricana (F.). Thirty-two structurally related compounds with chain lengths of 9–14 carbon atoms were exposed withE10–12∶Ac orE,E8,10–12∶Ac in traps in the field to investigate their influence on the activity of the attractants. Only alchols and acetates unsaturated at C-8, -9, or -10 greatly influenced moth captures. (Z) and (E)-8-dodecen-1-ol were weak synergists forE10–12∶Ac but no synergists forE,E8,10–12∶Ac were found. (Z) and (E)-8-dodecen-1-yl acetate and (E,E)-8,10-dodecadien-1-ol inhibited bothE10–12∶Ac andE,E8,10–12∶Ac while (E)-10-dodecen-1-ol, 10-dodecyn-1-ol, (Z) and (E)-9-dodecen-1-yl acetate, (Z)-10-dodecen-1-yl acetate, and undecyl acetate inhibited only the former attractant.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987788
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 57
    Digitale Medien
    Digitale Medien
    Mate-seeking behavior and reduced mating byEphestia cautella (Walker) in a sex pheromone-permeated atmosphere (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 507-515 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Almond moth ; Ephestia cautella ; Lepidoptera ; Pyralidae ; stored products ; pest management ; behavior ; density ; flight
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The mating rate ofEphestia cautella (Walker) was inversely related to the level of pheromone permeating the air. However, permeation did not prevent mating by altering the number of females calling or the frequency, duration, or pattern of male flight. Instead, permeation probably prevented mating by reducing the distance from which a male can respond to a female. The pheromone level necessary to achieve a particular reduction in mating increases with moth density.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987798
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 58
    Digitale Medien
    Digitale Medien
    Sex pheromone ofPandemis heparana (Den. and Schiff.) (Lepidoptera:Tortricidae) (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 663-670 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Pandemis heparana ; sex pheromone ; Lepidoptera ; Tortricidae ; gas chromatography ; mass spectrometry ; insect behavior ; (Z)-11-tetradecen-1-yl acetate ; (Z)-9-tetradecen-1-yl acetate ; (Z)-11-tetradecenl-ol ; tetradecyl acetate ; dodecyl acetate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract 90% (Z)-11-tetradecen-1-yl acetate, 5% (Z)-9-tetradecen-1-yl acetate, 5% (Z)-11-tetradecen-1-ol, dodecyl acetate (〈1%), and tetradecyl acetate (〈1%) were identified from gland extracts ofPandemis heparana females by gas chromatography and gas chromatography-mass spectrometry analysis (including mass fragmentography studies), chemical characterization, total synthesis, laboratory and field bioassays. In the field, a mixture of (Z)-11-tetradecen-l-yl acetate and (Z)-9-tetradecen-l-yl acetate (95∶5) was found to be essential for attractiveness ofP. heparana males.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00989635
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 59
    Digitale Medien
    Digitale Medien
    Effects of pheromone components and their degradation products on the response ofHeliothis spp. to traps (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 755-762 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Sex pheromone ; Heliothis virescens ; tobacco budworm ; Heliothis zea ; bollworm ; virelure ; Lepidoptera ; Noctuidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract None of the isolated degradation products of (Z)-11-hexadecenal [(Z)-11-HDAL] affected the catches of either tobacco budworm [Heliothis virescens (F.)] or bollworm [H. zea (Boddie)] moths when dispensed with pheromone from cotton dental rolls in cone traps. Also, none of the degradation products of (Z)-9-tetradecenal [(Z)-9-TDAL] had an effect on trap catches of tobacco budworm moths. Two of the three chemicals that have previously been identified in ovipositor washes of tobacco budworms but that are absent in those of bollworms caused a reduction in capture of bollworms: (Z)-9-TDAL (1.0 μg/trap) caused a 96% reduction in trap catch and (Z)-11-hexadecen-1-ol (20.0 μg/trap) caused a similar reduction. Tetradencenal (40 μg/trap) had no effect on trap catch.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00988316
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 60
    Digitale Medien
    Digitale Medien
    Response of the ichneumonid parasiteNemeritis canescens to Kairomones from the flour moth,Ephestia kuehniella (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 843-850 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Kairomones ; 2-acylcyclohexane-1 ; 3-diones ; Ephestia keuhniella Zeller ; (syn.Anagasta kuehniella Zeller) ; Lepidoptera ; Pyralidae ; Nemeritis canescens (Grav.) (syn.Venturia canescens (Grav.)) ; Ephestia cautella (Wlk.) ; Ephestia elutella (Hubner) ; Hymenoptera ; Ichneumonidae ; Plodia interpunctella (Hubner) ; oviposition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract 2-Acylcyclohexane-1,3-diones, a novel class of compounds in the larval mandibular glands ofEphestia(=Anagasta) kuehniella Zeller, act as kairomones. Their relative activities in eliciting oviposition responses from the larval parasiteNemeritis(=Venturia) canescens (Grav.) are reported.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00994784
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 61
    Digitale Medien
    Digitale Medien
    Pheromone hydrolysis by cuticular and interior esterases of the antennae, legs, and wings of the cabbage looper moth,Trichoplusia ni (Hübner) (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 859-866 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Antennae ; esterases ; pheromone degradation ; cuticle ; olfaction ; cabbage looper ; Trichoplusia ni ; Lepidoptera ; Noctuidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Examination was made of the hydrolytic activities of esterases obtained from the antennae, legs, and wings of 3-day-old cabbage looper moths,Trichoplusia ni (Hübner), by elution and by homogenation of those appendages. Pheromone hydrolysis in 1-min assays was monitored by use of tritium-labeled (Z)-7-dodecen-1-ol acetate and thin-layer chromatography to separate the reaction products. Listed according to the activities of the esterases obtained by homogenation, the organs were antennae 〉 legs 〉 wings. In contrast, the order according to the activities of the eluted esterases was wings 〉 legs 〉 antennae. Also, the eluted enzymes were less active than the esterases obtained by homogenization. The relatively high pheromone-hydrolyzing activity present in homogenized antennae suggests that the esterases originated inside the antennae and lends support to the hypothesis proposed in earlier investigations that pheromone-inactivating enzymes may play an important role in the olfactory process, possibly by clearing pheromone from the vicinity of the olfactory receptors. The esterases detected on the cuticle, on the other hand, may function by preventing surface accumulation of pheromone. The higher measured esterase activity in homogenates of prothoracic legs than of mesothoracic or metathoracic legs suggests that the prothoracic legs, which are used to clean the antennae of debris, may function by removing and degrading pheromone from the surface of antennae.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00994786
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 62
    Digitale Medien
    Digitale Medien
    Development of a bioluminescence assay for aldehyde pheromones of insects (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 923-933 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Aldehyde pheromone ; bioluminescence ; corn earworm ; Heliothis zea ; insect pheromone ; navel orangeworm ; Amyelois transitera ; western spruce budworm ; Choristoneura occidentalis ; spruce budworm ; Choristoneura fumiferana ; Lepidoptera ; assay for aldehydes ; Pyralidae ; Noctuidae ; Tortricidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Pheromone levels in the glands of individual female moths of the spruce budworm (Choristoneura fumiferana), the western spruce budworm (C. occidentalis), the navel orangeworm (Amyelois transitella), and the corn earworm (Heliothis zea) were quantitively measured by means of a new bacterial bioluminescence assay specific for aldehydes. The sensitivity and rapidity of the bioluminescent assay enabled studies to be conducted on the dependence of the pheromone levels in the spruce budworm on age and the effect of photoperiod on the pheromone levels in the corn earworm. The bioluminescence assay provides a rapid and sensitive approach for studying aldehyde pheromone levels and their regulation in insects.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987659
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 63
    Digitale Medien
    Digitale Medien
    Development of a bioluminescence assay for aldehyde pheromones of insects (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 935-945 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Aldehydes ; bioluminescence ; insect pheromones ; Porapak Q ; spruce budworm ; Choristoneura fumiferana ; Lepidoptera ; (E)-11-tetradecenal ; trapping ; bioassay for aldehydes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract A newly developed bioluminescent assay was used to measure quantitatively the amount of (E)-11-tetradecenal, the major component of the sex pheromone of the spruce budworm, trapped on Porapak Q®. The bioluminescent response was linearly related to the amount of aldehyde either deposited on the absorbent or trapped from an airstream. However, the recovery of pheromone from Porapak was dependent on whether the air was prefiltered (through Porapak) or taken directly from the atmosphere. Furthermore, pheromone on Porapak was lost with time during the flow of air through the absorbent, indicating that trapping of aldehyde pheromone should be conducted for short periods of time for optimal recoveries. The applicability of the assay system for the rapid and direct measurement of the release rates of aldehyde pheromone lures was demonstrated for pheromone lures used for baiting spruce budworm traps.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987660
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 64
    Digitale Medien
    Digitale Medien
    Sex pheromone of European grapevine moth (Lobesia botrana) its chemical transformations in sunlight and heat (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 973-980 
    Details
    ISSN: 1573-1561
    Schlagwort(e): (E, Z)-7,9-Dodecadien-1-yl acetate ; European grapevine moth ; Lobesia botrana ; Lepidoptera ; Tortricidae ; sex pheromone ; photoisomerization ; conjugated diene
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Photo- and radical isomerization of (E, Z)-7,9-dodecadien-1-yl acetate (DDA) leads to an equilibrium mixture of all four possible geometric isomers of 7,9-DDA in the ratio ofE,E, 69–76%;Z,E, 11–13%;E, Z, 12–15%; andZ, Z, 1–3%. Iodine catalysis of the isomerization takes place even in dark at room temperature and is probably a radical reaction.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987663
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 65
    Digitale Medien
    Digitale Medien
    Composition, quantification, and periodicity of sex pheromone gland volatiles from individualHeliothis virescens females (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 1043-1055 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Heliothis virescens ; Lepidoptera ; Noctuidae ; Z11-16:Ald ; 16:Ald ; Z9-14:Ald ; 14:Ald ; sex pheromone emission ; gland volatiles ; blend composition ; pheromone emission rates
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Sex pheromone gland volatiles from individualHeliothis virescens (F.) females were collected and analyzed on an SP-2330 capillary gas-liquid chromatography column for identification and quantification of the compounds emitted. Only four of the seven compounds previously reported as pheromone components appeared consistently in the volatile collections: 14:Ald, Z9-14:Ald, 16:Ald, and Z11-16:Ald. The female glands did not emit the same amounts of these compounds throughout a 24-hr period; they emitted maximum quantities between 6 and 11 hr after the onset of scotophase with the remainder of the photoperiod having minimal emission rates. Although the absolute quantities fluctuated, the percent compositions of the compounds remained about the same throughout the 24-hr period.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987885
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 66
    Digitale Medien
    Digitale Medien
    Fine structure of the larval rhinophores of the nudibranch, Rostanga pulchra, with emphasis on the sensory receptor cells (1982)
    Springer
    Cell & tissue research 225 (1982), S. 235-248 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Rhinophore ; Larva ; Nudibranch ; Sensory cell ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The rhinophores of the veliger larva of Rostanga pulchra are located in the intravelar field near the base of the velar lobes. Each rhinophore is a cylindrical structure, tapering distally, and covered with a dense meshwork of microvilli. A conspicuous row of ciliary tufts runs along each side of the rhinophore and several stiffer tufts, composed of fewer cilia, are positioned around the tip or at the base. The rhinophoral epithelium consists of supporting cells, ciliated cells (giving rise to the ciliary rows), dendritic terminals (giving rise to the tufts around the apex), and sinuses containing occasional amebocytes. The lumen of the rhinophore is occupied by the rhinophoral ganglion and muscle cells that are oriented in two perpendicular planes. Cell bodies of the dendritic endings are located within the rhinophoral ganglion, which in turn joins into the optic and cerebral ganglia. Rhinophoral ganglionic neurons do not synapse with each other, but numerous neuromuscular synapses are found in the lumen of the rhinophore. Morphological evidence suggests that the dendritic endings are chemoreceptors and the ciliated cells are possibly mechanoreceptors but are not functional at this stage in development. The functional role of the rhinophores is discussed in relation to larval behavior at settlement and metamorphosis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00214678
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 67
    Digitale Medien
    Digitale Medien
    Ultrastructure of pinealocytes of the kangaroo rat (Dipodomys ordi) (1982)
    Springer
    Cell & tissue research 226 (1982), S. 167-175 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pineal gland ; Ultrastructure ; Kangaroo rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of the pinealocytes of the wild-captured ord kangaroo rat (Dipodomys ordi) was examined. A homogeneous population of pinealocytes was present in the pineal gland of the kangaroo rat. The Golgi apparatus, granular endoplasmic reticulum, mitochondria, lysosomes, dense-core vesicles, vacuoles containing a flocculent material and lipid droplets were consistent components of the pinealocyte cytoplasm, whereas infrequently-observed organelles included centrioles, multivesicular bodies, subsurface cisternae, “synaptic” ribbons and cilia. The number of dense-core vesicles was relatively high and dense-core vesicles and vacuoles containing a flocculent material were present in the same cell. Although it has been recently suggested that two different secretory processes, i.e., neurosecretory-like (Golgi apparatus — dense-core vesicles) and ependymal-like (granular endoplasmic reticulum — vacuoles containing a flocculent material) may be involved in different regulatory mechanisms in the pinealocytes, the definitive answer to this is still far from clear. Therefore, the pineal gland of the kangaroo rat appears to be a good model for the study of the potential relationship between these two secretory processes, especially in respect to seasonal changes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00217091
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 68
    Digitale Medien
    Digitale Medien
    The fine structure of the polymorphic spermatozoa of Fusitriton oregonensis (Mollusca: Gastropoda), with notes on the cytochemistry of the internal secretions (1982)
    Springer
    Cell & tissue research 227 (1982), S. 235-255 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Sperm polymorphism ; Ultrastructure ; Mollusca ; Prosobranchia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The prosobranch Fusitriton oregonensis exhibits an unusual form of sperm polymorphism. The viable, eupyrene sperm are attached in groups of about fifty to worm-shaped, apyrene, carrier sperm. There is a second apyrene sperm, which is lancet-shaped and has a different internal organization than the carrier, but does not transport eupyrene sperm. The eupyrene sperm are filiform (185 μm long), with a conical acrosome, elongate nucleus and midpiece. They contain large stores of glycogen in the principal piece, together with an unusually high proportion of protein. The latter is due to a complex interconnecting system of fibres that supports the tail internally. A distinct annulus is located, characteristically, at the junction between midpiece and principal piece. The carrier sperm has a core of about 112 axonemes that arise from basal bodies in the anterior end and extend through its entire length of 36 μm. The basal bodies have unstriated rootlets that are embedded in a granular cap. Large membrane-bound “yolk bodies” are arranged along the length of the carrier sperm, on either side of the median axonemal core. Dense bodies, which may be indigestible residues formed from the degeneration of the nucleus, are excreted by exocytosis. Individual carrier sperm are capable of “corkscrew” propulsion, resembling that of spirochaetes. The lancet sperm is three times as long as the carrier. The sixteen or so axonemes, which are arranged peripherally like a cage enclosing the cytoplasm, originate from a dense centriolar plate in the anterior end. The cytoplasm is filled with secretions including small yolk granules, dense bodies (also excreted), clear vesicles, and a membranated granular secretion that resembles mucus. The possible functions of the lancet and carrier sperm are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210883
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 69
    Digitale Medien
    Digitale Medien
    Three-dimensional organization of smooth muscle cells in blood vessels of laboratory rodents (1982)
    Springer
    Cell & tissue research 227 (1982), S. 429-437 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Smooth muscle ; Arteriole ; Three-dimension ; Ultrastructure ; Laboratory rodents
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Three-dimensional aspects of smooth muscle cells of the microvas-culature were studied ultrastructurally in laboratory rodents by means of serial thin sections and reconstruction of muscle cell models. It was demonstrated that a muscle cell of an arteriole (luminal diameter (LD) 17 μm) in hamster striated muscle was spindle-shaped, 70 μm long, and wound twice round the vessel axis. The volume of the cell was calculated as 750 μm3 and its surface area as 1330 μm2. A muscle cell in an arteriole (LD 6 μm) in the rat retina was irregular in shape, about 22 μm long, and had branched processes. The cell volume was calculated as 139 μm3 and its surface area as 298 μm2.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210897
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 70
    Digitale Medien
    Digitale Medien
    The interstitial cells in the colon of the rabbit (1982)
    Springer
    Cell & tissue research 222 (1982), S. 41-51 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Ultrastructure ; Interstitial cell ; Myenteric plexus ; Colon ; Rabbit
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The interstitial cells associated with the myenteric plexus of the rabbit colon were studied by scanning and transmission electron microscopy. It was demonstrated that the interstitial cells were stellate or fusiform in shape and located over the ganglia, over nerve bundles and between muscle cells. They were characterized by many slender processes, and resemble fibroblasts. No basal lamina was observed between the interstitial cells and muscle cells. It was concluded that structural features of the interstitial cells are distinctly different from those of neurons, Schwann cells, or of smooth muscle cells, while they show clear similarities to those of fibroblasts. By scanning electron microscopy the shapes and the relations of these cells could be demonstrated in great detail.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218287
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 71
    Digitale Medien
    Digitale Medien
    Noradrenergic axon terminals in the substantia gelatinosa of the rat spinal cord (1982)
    Springer
    Cell & tissue research 222 (1982), S. 359-378 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Axon terminals ; Substantia gelatinosa ; Spinal cord ; Noradrenaline ; Ultrastructure ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The noradrenergic terminals in the substantia gelatinosa of the dorsal horn of the cervical spinal cord of the rat were investigated by means of the histofluorescence technique and electron-microscopic cytochemistry using the glyoxylic acid-KMnO4 fixation technique. In accordance with the topographical distribution of fluorescent catecholaminergic fibers, noradrenergic terminals containing small granular vesicles were frequently observed electron microscopically in the outer layer of the substantia gelatinosa. These terminals were most frequently found to appose without showing typical synaptic features, small-caliber dendrites, spine apparatus, and rarely, large caliber dendrites. Only in a few cases, the noradrenergic terminals exhibited typical synaptic contacts with dendritic elements of small size. In addition, noradrenergic terminals apposed non-noradrenergic terminals containing small agranular vesicles. In rats bearing surgical lesions of the dorsal roots, no noradrenergic terminal were found in contact with the degenerated axon terminals in the substantia gelatinosa. These findings suggest that the noradrenergic afferents to the substantia gelatinosa may exert their influence on sensory transmission via dorsal horn cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213218
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 72
    Digitale Medien
    Digitale Medien
    Presence of dense-core vesicles in pinealocytes of the cat (1982)
    Springer
    Cell & tissue research 222 (1982), S. 695-698 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pineal gland ; Ultrastructure ; Dense-core vesicles ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Dense-core vesicles, 90–200 nm in diameter, were found in pinealocytes of the cat. They were present both in perikarya and cell processes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213868
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 73
    Digitale Medien
    Digitale Medien
    Ultrastructural immunocytochemical characterization of isotocin, vasotocin and neurophysin neurons in the magnocellular preoptic nucleus of the goldfish (1982)
    Springer
    Cell & tissue research 223 (1982), S. 685-694 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Immunoelectron microscopy ; Preoptic nucleus ; Goldfish ; Magnocellular neuroendocrine cells ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary We describe the ultrastructural localization of isotocin, vasotocin and neurophysin in the magnocellular preoptic nucleus of the goldfish. With the aid of immunocytochemical techniques, we see staining both in classical neurosecretory granules and in diffuse agranular form throughout somata and processes. Signs of cellular and synaptic interactions between chemically identified neurons include axon terminals which contain vasotocin immunoreactivity and membrane specializations (puncta adhaerentia) between adjacent somata. Our investigations provide an anatomical basis for neuroendocrine and neurotransmitter-like functions of peptidergic neurons in the teleost preoptic nucleus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218487
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 74
    Digitale Medien
    Digitale Medien
    The pinealocyte nucleolus (1982)
    Springer
    Cell & tissue research 224 (1982), S. 195-206 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pinealocytes ; Nucleolus ; Rat ; Ultrastructure ; Twenty-four-hour changes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary An ultrastructural and morphometric analysis was made of the nucleolar components in pinealocytes of 40 male Fischer rats sampled at eight times in an LD 12∶12 photoperiod cycle. Comparisons of results from the eight times showed variation in estimated mean volume of the granular component of ±29%, and of the fibrillar component ±11%, in relation to daily means. Peaks in mean volume of total nucleolus and its granular component occurred at 1 h of light. Near maximal and minimal mean volumes of the fibrillar component both occurred during both light and dark. Fibrillar centers (nucleolar organizer regions) of different sizes were found at all sampling times. It is concluded that temporal patterns in 24-h changes in the nucleolar components are most prominent in the granular component, and are more complex than suggested by changes in total nucleolar size or mean dimensions, and than represented by a simple biphasic circadian rhythm. Examples of different stages in the migration of the granular component, and of possible sites of nucleo-cytoplasmic transfer of nucleolar material, are described.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00217279
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 75
    Digitale Medien
    Digitale Medien
    Ultrastructure of gut-associated lymphoid tissue (GALT) in the amphibian urodele, Pleurodeles waltlii (1982)
    Springer
    Cell & tissue research 224 (1982), S. 663-671 
    Details
    ISSN: 1432-0878
    Schlagwort(e): GALT (gut-associated lymphoid tissue) ; Urodeles ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé L'ultrastructure du tissu lymphoïde associé au tube digestif (GALT) a été étudiée chez l'amphibien urodèle, Pleurodeles waltlii. Les follicules lymphoïdes se présentent comme de vrais infiltrés entre les éléments conjonctifs de la muqueuse. Ils se trouvent principalement constitués par des plasmocytes mûrs et en développement, des macrophages et des granulocytes. Les cellules lymphoïdes migratrices provoquent une invasion massive de l'épithelium intestinal qui présente des modifications notables comme la disparition de la membrane basale et une diminution du nombre de cellules muqueuses. D'après son organisation et ses composants cellulaires, le GALT de P. waltlii semble représenter un précurseur phylogénétique primitif de la “barrière immunologique intestinale” des mammifères.
    Notizen: Summary The ultrastructure of gut-associated lymphoid tissue (GALT) has been studied in the salamander, Pleurodeles waltlii. Lymphoid accumulations appear as true infiltrates scattered throughout the lamina propria cell elements. The most important components of these infiltrates are small and medium sized lymphocytes, and, in lesser amounts, developing and mature plasma cells, macrophages and granulocytes. Migrating lymphoid cells massively invade the intestinal epithelium inducing noticeable modifications, such as the disappearance of the basement membrane and decreased numbers of mucous cells. Thus, in its organization and cell composition, the GALT of P. waltlii appears to represent a primitive phylogenetic precursor of the mammalian “intestinalimmunologic ” barrier.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213761
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 76
    Digitale Medien
    Digitale Medien
    Histotopography and ultrastructure of the thin limbs of the loop of Henle in the hamster (1982)
    Springer
    Cell & tissue research 225 (1982), S. 111-127 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Loops of Henle ; Thin limbs ; Kidney (hamster) ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the kidney of the Syrian hamster the descending thin limbs of both the short and long loops of Henle are not spatially separated from each other and descend between the vascular bundles. Ultrastructurally, five different epithelial types are distinguished in the thin limbs of the short and long loops of Henle. Short loops possess only a descending thin limb with a simply organized epithelium (type 1). Long loops comprise an upper and a lower part of the descending thin limb and the ascending thin limb. The upper part of the long descending thin limb is equipped with a complex and highly interdigitating epithelium with shallow junctions (type 2), which gradually transforms into the simple noninterdigitating type-3 epithelium of the lower part. In a minor portion of long descending thin limbs, however, the upper part begins with an even more complexly organized epithelium (type 2a) than type 2. Type-2a epithelium is conspicuously thicker and possesses a more elaborate mode of cellular interdigitation. Along the descent of this tubular part through the inner stripe of the outer medulla, type-2a epithelium transforms into type-2 epithelium. It is suggested that the long descending thin limbs, which start with type-2a epithelium, belong to the longest loops. The type-4 epithelium of the ascending thin limbs is characterized by flat and extensively interdigitating cells with shallow junctions. The unique pattern of the type-2 a epithelium favors the assumption that solute secretion essentially contributes to the increase in concentration of tubular fluid in long descending thin limbs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216222
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 77
    Digitale Medien
    Digitale Medien
    Effects of acute opiate-peptide administration on pro-opiomelanocortin cells of the intermediate lobe of the rat pituitary (1982)
    Springer
    Cell & tissue research 225 (1982), S. 217-222 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Opiate peptides ; Pituitary ; Pro-opiomelanocortin cells ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effects of acute injections of synthetic opiate peptides into the lateral cerebral ventricle of young adult male rats on cells of the intermediate lobe of the pituitary were studied. Met-enkephalin (100/μg) injected into anesthetized rats, or 20 μg beta-endorphin administered via a previously implanted cannula to unanesthetized animals, will lead to cell degranulation and often to expanded Golgi zones and prominent regions of rough endoplasmic reticulum in secretory cells when tissue is fixed 45–60 min after peptide administration. Treatment of animals with the opiate antagonist naloxone hydrochloride prior to enkephalin injection appeared to prevent the cellular changes elicited with peptide alone. Observations suggest that opiate peptides administered to the cerebrospinal fluid may stimulate release of pro-opiomelanocortin-peptide from pituitary cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216230
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 78
    Digitale Medien
    Digitale Medien
    Development of the ovarian surface and associated germ cells in the human fetus (1982)
    Springer
    Cell & tissue research 226 (1982), S. 493-510 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Ovarian cords ; Surface epithelium ; Fetal germ cells ; Mesonephros ; Ultrastructure ; SEM
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ovarian surface and associated germ cells have been studied in human fetuses from 12 weeks of age until near term, using light, TEM and SEM techniques. The surface epithelium and related cords proliferate extensively, especially at midterm. The cords in the ovarian cortex appear to be linked with ingrowths from the surface epithelium, and both structures have a common basal lamina. Germ cells are always interspersed among the somatic cells of the surface epithelium and associated cords. These results indicate that both the proliferating cords and surface epithelium may contribute to the formation of early follicles. Furthermore, the occurrence, of elements having some of the features of primitive steroidogenic cells in the regions of cordsurface epithelium continuity, suggests that both structures (surface epithelium and cords) contribute somatic cells, which in addition to becoming granulosa cells, might also contribute to the provision of primitive interstitial cells. Gonocytes tend to migrate through the developing ovarian tissue towards the surface where they become extruded into the peritoneal cavity. This phenomenon might contribute to the reduction in the number of germ cells at birth and parallels the atretic processes within the ovary.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00214779
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 79
    Digitale Medien
    Digitale Medien
    A quantitative ultrastructural analysis of changes in hamster cheek-pouch epithelium treated with vitamin A (1982)
    Springer
    Cell & tissue research 226 (1982), S. 541-554 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Oral epithelium ; Cell differentiation ; Vitamin A ; Ultrastructure ; Stereology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructural changes induced by the topical application of retinol acetate on hamster cheek pouch epithelium were evaluated using stereological analysis. Electron micrographs were prepared of the basal and superficial regions of the nucleated cell layer of the epithelium obtained from 3 treated and 3 control animals and examined at two levels of magnification. A total of 528 micrographs were analyzed using a coherent double lattice test system. Although the mean thickness of the nucleated cell layer did not change significantly after 10 days of treatment with retinol acetate the formation of keratinized squames was completely inhibited. This was paralleled by significant changes in the volume density of a number of organelles in both the basal and superficial strata. Rough endoplasmic reticulum increased significantly whereas filaments, which maintained a constant diameter of approximately 9 nm, keratohyalin granules and membrane-coating granules decreased in both strata. Desmosomes also showed a significant decrease in numerical area density in the treated tissues. In contrast, no changes were observed in the volume density of the Golgi apparatus, free ribosomes or mitochondria in the treated epithelium. It is concluded that this treatment provides an epithelium lacking all features of keratinization and may be a useful model for examining metabolic activities specifically associated with keratinization.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00214783
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 80
    Digitale Medien
    Digitale Medien
    The structure of a hair mechanoreceptor in the antennule of crayfish (Crustacea) (1982)
    Springer
    Cell & tissue research 226 (1982), S. 565-578 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Mechanosensory hair ; Chordotonal organ ; Ultrastructure ; Crustacea
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In this study we examine the fine structure of mechanosensory hairs in the antennule of crayfish. The sensory hair is a stiff shaft with feather-like filaments. The hair's base is a large expansion of membrane which allows the hair shaft to deflect. The sensory transducing elements are located far from the hair, but are coupled mechanically with the hair shaft by a fine extracellular chorda. The sensory element is a type of scolopidium which consists of a scolopale cell and three sensory cells with a 9 + 0 type ciliary process. This type of scolopidium is characteristic of the chordotonal organ that has no cuticular structure on the surface of the exoskeleton. In this crustacean hair receptor, the deflection of the cuticular hair is transmitted through the chorda to the scolopidium which is a tension-sensitive transducer. The present study reveals that the mechanosensory hair of decapod crustaceans is a chordotonal organ accompanied by a cuticular hair structure. We also discuss comparative aspects of cuticular and subcuticular chordotonal organs in arthropods.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00214785
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 81
    Digitale Medien
    Digitale Medien
    Correlation of mitochondrial form and function in vivo: Microinjection of substrate and nucleotides (1982)
    Springer
    Cell & tissue research 227 (1982), S. 129-137 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Mitochondria ; Ultrastructure ; Microinjection ; ATP ; ADP ; Amoeba proteus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Microinjection of adenine nucleotides and substrates into the cytoplasm of Amoeba proteus followed by EM examination has been used in an attempt to relate alterations in mitochondrial morphology with functional changes. Contracted mitochondria with dark matrix and wide cristae (Type I), and expanded mitochondria with light matrix and narrower cristae (Type II) coexist in normal active amoebae, but their numbers can be varied according to different cell activity states. Following injection of ATP, the mitochondria of the amoebae showed a time-dependent movement towards a predominately Type II form, whilst injections of ADP produced predominately the Type I form. Injection of succinate or deionised water, even in large amounts, had little effect on the numbers of Type I or Type II forms. The change induced by ATP was of long duration; that induced by ADP was influenced by both concentration injected and the cell's substrate levels. With 3 mM solutions of ADP the mitochondrial population was primarily of Type I organelles; higher ADP concentrations or the simultaneous injection of succinate, however, resulted in a switch with time to increased proportions of Type II mitochondria. The results extend the findings of previous in vivo and in vitro mitochondrial studies and are discussed in the light of these.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00206336
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 82
    Digitale Medien
    Digitale Medien
    A light- and electron-microscopic study on the migration of primordial germ cells in the teleost, Oryzias latipes (1982)
    Springer
    Cell & tissue research 227 (1982), S. 139-151 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Migration ; Primordial germ cell ; Teleost ; Oryzias latipes ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The primordial germ cells (PGCs) of Oryzias latipes in migration to the gonadal anlage have been investigated by light and electron microscopy. The ultrastructure of the PGCs, which occur in the subendodermal space on the syncytial periblast, differ conspicuously from that of the surrounding endodermal cells. After the PGCs move to the cavity between lateral plate and ectoderm, they are taken into the somatomesodermal layer and transferred to the dorsal mesentery where they form gonadal anlage with mesodermal cells. During their translocation to the dorsal mesentery through the somatic mesoderm, apparently without formation of pseudopods, the PGCs are completely surrounded by mesodermal cells. Since these conditions seem unfavorable to the active translocation of the PGCs to the dorsal mesentery, it is more likely that the PGCs are transferred passively by the morphogenic activity of the lateral-plate mesoderm. Counts of the number of the PGCs revealed that they are mitotically dormant during the migratory period. After the completion of the migration, they regain their proliferative activity. The PGCs in the female proliferate more actively than those in the male, which provides the first morphological indication of sex differentiation in this species of fish.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00206337
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 83
    Digitale Medien
    Digitale Medien
    Ingrowth of optic nerve fibers and onset of myelin ensheathment in the optic tectum of the trout (Salmo gairdneri) (1982)
    Springer
    Cell & tissue research 227 (1982), S. 201-211 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Optic systems ; Axonal growth ; Myelination ; Ultrastructure ; Teleosts
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The early differentiation of the optic pathway of the trout was studied by means of autoradiography, silver impregnation and electron microscopy. Ingrowth of optic nerve fibers into the optic tectum was consistently shown by tracer application and Golgi studies to occur at stage 28, about one week before hatching. Fibers being arranged in discrete bundles were rapidly growing through the longitudinal axis of tectum and at stage 33 reached its posterior end. Cross sections of these fiber bundles at different positions revealed myelin ensheatment to be initiated at the end of stage 34 at the anterior pole of the tectum. Since in the optic nerve of the trout the onset of myelination occurred even earlier (stage 33), it is assumed that this differentiation process follows a rostro-caudal gradient during development of the optic pathway.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00206341
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 84
    Digitale Medien
    Digitale Medien
    Sensory input to growth stimulating neuroendocrine cells of Lymnaea stagnalis (1982)
    Springer
    Cell & tissue research 227 (1982), S. 371-386 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Tentacle sensory input system ; Neuroendocrine control of growth ; Ultrastructure ; L. stagnalis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Several environmental factors influence the growth of the basommatophoran freshwater snail Lymnaea stagnalis. Growth is hormonally controlled by 4 cerebral clusters of ca 50–75 peptidergic, neuroendocrine Light Green Cells (LGC). The present light, transmission, and scanning electron microscopic study shows that the LGC are synaptically contacted by a tentacle sensory system (TSS). The TSS consists of 2 types of primary sensory neurone, viz. ca 150 S1-cells and ca 50–100 S2-cells. A S1-cell has a non-ciliated dendrite and an axon branch that synaptically contacts the soma of a S2-cell. A S2-cell has a branching, ciliated dendrite. Probably, S1- and S2-cells have different sensory modalities and can integrate sensory information by intersensory interaction. The S2-axons run through the tentacular nerves, the cerebral ganglia, and the intercerebral commissure. In each ganglion S2-axons branch and form synaptic contacts on the axons and somata of the LGC and on glial cells that surround the LGC. In an LGC-cluster, 1–3 LGC-somata are particularly strongly innervated. Probably, the TSS is involved in the environmental control of growth in L. stagnalis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210892
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 85
    Digitale Medien
    Digitale Medien
    Lack of correlation between ultrastructural and pharmacological types of non-adrenergic autonomic nerves (1982)
    Springer
    Cell & tissue research 221 (1982), S. 551-581 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Non-adrenergic, non-cholinergic nerves ; Cholinergic nerves ; Ultrastructure ; Nervous transmission
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In order to test the premise that non-adrenergic, non-cholinergic (NANC) autonomic nerves have a distinctive ultrastructural appearance, clearly different from that of cholinergic nerves, a detailed quantitative ultrastructural analysis has been made of the non-adrenergic innervation of 15 tissues thought from pharmacological evidence to be innervated by NANC nerves (rat and rabbit anococcygeus muscles; rabbit hepatic portal vein; extrinsically denervated toad lung); cholinergic nerves (atria of rat, rabbit, guinea-pig and toad); or both (guinea-pig cervical and thoracic trachealis muscle; rabbit rectococcygeus muscle; urinary bladder of rat, rabbit, guinea-pig and toad) in addition to their adrenergic supply. Following fixation with a modified chromaffin procedure allowing identification of adrenergic nerves, large, randomly selected samples of non-adrenergic nerve profiles from each tissue were analysed with respect to numbers, relative proportions, and size frequency distributions of different vesicle classes within the profiles. The neuromuscular relationships within each tissue were also analysed. On the basis of these analyses, it is clear that there are no consistent ultrastructural differences between cholinergic and NANC autonomic nerves: neither proportions nor sizes of the vesicles provide any clue as to the transmitter used by a particular nerve. The great majority of nerve profiles, whether cholinergic or NANC, contain predominantly small clear “synaptic” vesicles. Large filled “peptidergic” vesicles are no more common in most NANC nerves than in most cholinergic ones. It is concluded, on ultrastructural grounds, that the primary transmitter in these NANC autonomie nerves is most likely to be stored in and released from the small clear vesicles.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215701
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 86
    Digitale Medien
    Digitale Medien
    Comparative study of structure and function of blood cells from two Drosophila species (1982)
    Springer
    Cell & tissue research 221 (1982), S. 607-615 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Hemocytes ; Drosophila ; Ultrastructure ; Phagocytosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Hemocytes of Drosophila melanogaster and Drosophila yakuba larvae have been defined in terms of their ultrastructure and functions in “coagulation”, wound healing, encapsulation, phenol-oxydase activity, and phagocytosis. The position of these cells among the classical hemocyte types of insects is determined. We distinguish two plasmatocyte types (macrophage plasmatocytes and lamellocytes) which do not seem to belong to the same lineage, and oenocytoids which are the crystal cells of the literature.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215704
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 87
    Digitale Medien
    Digitale Medien
    A comparative ultrastructural and physiological study on melanophores of wild-type and periodic albino mutants of Xenopus laevis (1982)
    Springer
    Cell & tissue research 222 (1982), S. 1-9 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Melanophores ; Periodic albinism ; Ultrastructure ; Physiology ; Xenopus laevis, tadpoles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Pigment of tail-fin melanophores in periodic albino Xenopus laevis tadpoles is dispersed in response to darkness and to α-MSH in a manner similar to wild-type melanophores. However, periodic albino tadpoles lack the response to different background conditions and the melatonin-induced aggregation in darkness. The tyrosinase activity in cells of the latter type tadpoles is weak compared to the wild-type cells. Ultrastructural examination of melanophores from periodic albino mutants and cells from wild-type tadpoles shows similar organelles at corresponding sites. A morphological difference can be observed in the fine structure of the melanosomes, which in albinos resembles an earlier stage of development. It is postulated that periodic albino Xenopus laevis possess the cellular mechanism to disperse pigment in the melanophores, but that under physiological conditions the release of α-MSH appears to be absent or scarce.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218284
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 88
    Digitale Medien
    Digitale Medien
    Fine structure of seminiferous tubules from prenatally irradiated rats (1982)
    Springer
    Cell & tissue research 222 (1982), S. 143-152 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Sertoli cells ; Seminiferous tubules ; Irradiated rats ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of the seminiferous tubules was studied in rats that had been subjected to whole body irradiation on the 19th day of gestation. The seminiferous tubules from 3 months-old irradiated animals are devoid of germ cells and contain only Sertoli cells. Compared with controls of the same age, the seminiferous tubule basal membrane is thickened and multilayered and several alterations are observed in the Sertoli cells. The most characteristic of these alterations are: (a) an abnormal number of nuclear heterochromatin clumps, (b) the presence of numerous cytoplasmic vacuoles and various sized lipid droplets, (c) elaborate interdigitations and junctions between adjacent cells, and (d) the presence of anomalous ectoplasmic specializations disposed perpendicularly to the Sertoli cell membrane.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218294
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 89
    Digitale Medien
    Digitale Medien
    Ultrastructural observations on the pineal gland of the Chinese hamster, Cricetulus griseus (1982)
    Springer
    Cell & tissue research 222 (1982), S. 531-546 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pineal gland ; Ultrastructure ; Chinese hamster (Cricetulus griseus)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of the pineal parenchymal cells, pinealocytes and glia-like cells, of the Chinese hamster (Cricetulus griseus) is described. Pinealocyte nuclei contain spindle-shaped inclusions consisting of bundles of closely packed parallel filaments of about 8 nm in thickness. Mitochondria contain lamellar and tubular cristae. Smaller and larger mitochondria are usually localized separately in individual pinealocytes. Flattened mitochondria contain two to four closely arranged, unusual lamellar cristae, which lie parallel to the surface of the mitochondria. These cristae exhibit particular structures. Rough endoplasmic reticulum is frequently found in close association with such flattened mitochondria. Tubular expansions of the outer membrane of mitochondria occur frequently. The pinealocyte cytoplasm contains stacks of flattened cisternae, which are continuous with both smooth and rough endoplasmic reticulum. Pinealocyte cell bodies and processes contain granulated vesicles. Although larger granulated vesicles measuring up to 300 nm in diameter occasionally occur, smaller granulated vesicles (about 100 nm in diameter) and larger ones are usually localized separately in individual cells. Vacuoles containing flocculent material are found in groups in close association with rough endoplasmic reticulum. Glia-like cells with darker cytoplasm and nuclei lie surrounding pericapillary or intercellular spaces. The glia-like cells are characterized by the presence of abundant lipid droplets and occasional pigment granules. Bundles of filaments run parallel to the long axis of the processes of the glia-like cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213853
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 90
    Digitale Medien
    Digitale Medien
    The life cycle of the gastrin granule (1982)
    Springer
    Cell & tissue research 222 (1982), S. 479-491 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Gastrin cell ; Secretory granules ; Secretory process ; Peptide hormones ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of gastrin cells in the rat antrum was analyzed with standardized and quantitative planimetric methods. Resting and active cells were compared. The gastrin cells were activated by removal of the acidproducing part of the stomach (fundectomy). As a result the serum gastrin concentrations were greatly elevated. Compared with gastrin cells in fasted control rats the gastrin cells in fundectomized rats were increased in number, contained fewer cytoplasmic granules, increased amount of endoplasmic reticulum, and an enlarged Golgi area. Generally, the secretory granules of the gastrin cell displayed a wide range of electron density from highly electron-dense to electron-lucent. They exhibited certain characteristic features: 1) Electron-dense granules made up a greater proportion of the total granule population in active gastrin cells than in resting cells. 2) Electron-dense granules were more frequent near the Golgi stacks than in the periphery of the cell. 3) Electron-dense granules were smaller in size than the electron-lucent granules; hence, small electron-dense granules probably represent young granules (progranules), while large, electron-lucent granules represent mature (old) granules. 4) Electron-dense granules invariably displayed a more intense immunoreactivity than electron-lucent granules. The gastrins are generated from a large precursor molecule. The posttranslational processing of this precursor is reflected in the gastrin-component pattern. The gastrin-component pattern in antral extracts of fundectomized and normal fasting rats differed in that the proportion of the gastrin-4-like component was reduced, whereas the gastrin-34-like component was increased in the fundectomized rats. The results suggest a greater proportion of small gastrin components in the mature granules than in the newly formed ones, presumably due to more extensive conversion of larger forms into smaller forms with a longer granule half-life. As a result gastrin-17-and gastrin-34-like components make up a larger proportion of total gastrin in active gastrin cells than in resting gastrin cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213849
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 91
    Digitale Medien
    Digitale Medien
    Primary cultures of endothelial cells of the rat liver (1982)
    Springer
    Cell & tissue research 223 (1982), S. 201-215 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Liver ; Endothelial cells ; Primary culture ; Ultrastructure ; Adsorptive endocytosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A new isolation and purification procedure for endothelial cells of the rat liver and the conditions for large scale survival of these cells in maintenance culture are reported. Cells isolated by this new method and cultured with homologous rat serum on a collagen matrix show the restoration of several ultrastructural characteristics typical of rat liver endothelial cells in situ, including the broad cytoplasmic extensions that contain the sieve plates. These fenestrated cytoplasmic projections, which cover the liver sinusoids in vivo, are well preserved and are reformed in a manner reminiscent of the situation in situ. Reformation of specific membrane receptors is indicated by the reappearance of the capacity to take up horseradish peroxidase by adsorptive endocytosis, a characteristic that is lost during the cell isolation procedure. From the results obtained in this study, maintenance culture of rat liver endothelial cells seems to be a promising system for studying the regulation of pore size of the fenestrated sieve plates by alcohol and certain hormones, for studying the interaction of endothelial cells with other liver cells and tumor cells, and for studying the mechanisms of adsorptive endocytosis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221510
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 92
    Digitale Medien
    Digitale Medien
    Electron-microscopic study of the development of the periarteriolar zone in splenic white pulp of rats (1982)
    Springer
    Cell & tissue research 223 (1982), S. 335-348 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Spleen (rat) ; Ultrastructure ; Periarteriolar lymphatic sheath ; Interdigitating cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary To obtain more information concerning the origin of interdigitating cells, the postnatal development and morphology of the periarteriolar lymphatic sheath in splenic white pulp of rats was investigated by light- and electron-microscopy. Special attention was paid to the ontogeny of interdigitating cells. The spleens of the animals were studied in the age range from 1 h to 28 days after birth. The splenic white pulp of neonatal rats consists only of a few reticuloblasts, which are concentrically arranged around central arterioles. After 21 h an increase in promonocytes and monocytes was noted. Between the fifth and seventh postnatal day monocytogenic cells with a light and almost translucent cytoplasm appear, which display long cytoplasmic projections between the adjacent cells. Neighbouring lymphocytes often insert finger-like processes into the invaginated cellular membrane of these transitional forms. This intimate cellular contact is supported by zonulae occludentes. These cells represent transitional forms between monocytes and interdigitating cells. From seven days of age onwards typical interdigitating cells were present as in adult animals. After the differentiation into an inner and outer periarteriolar lymphatic sheath, the T-cell-dependent area of splenic white pulp has attained its adult appearance and further changes are not to be expected. On the basis of these findings, it is highly probable that interdigitating cells develop via transformation of monocytes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01258494
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 93
    Digitale Medien
    Digitale Medien
    Ultrastructure of scales in a teleost (Carassius auratus L.) after use of rapid freeze-fixation and freeze-substitution (1982)
    Springer
    Cell & tissue research 223 (1982), S. 349-367 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Teleost scales ; Ultrastructure ; Rapid freeze-fixation ; Mineralization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Resumé Des précisions concernant les aspects ultrastructuraux des dépôts minéraux dans les écailles deCarassius auratus ont été obtenues grâce à l'utilisation de la congélation ultra-rapide suivie d'une cryosubstitution en milieu anhydre. Ces données sont comparées à celles fournies par les méthodes usuelles utilisant des fixateurs aqueux. La couche externe des écailles comprend des fibres collagènes disposées sans ordre apparent. Les dépôts minéraux se produisent surtout dans la substance interfibrillaire où des granules denses semblent représenter des sites actifs au cours de la minéralisation apparentée au type sphéritique. La plaque basale comporte deux catégories de fibres collagènes. Les unes, les plus nombreuses, de plus fort diamètre, sont organisées en lamelles formant une structure en contre-plaqué; les autres appelées “fibres TC”, orientées de la base de l'écaille vers la zone superficielle, jouent un rôle important dans les premières phases de la minéralisation de type inotropique dans cette partie de l'écaille. Dans les deux couches de l'écaille, la phase minérale est surtout trouvée dans la substance interfibrillaire. De ce fait, les écailles élasmoides des Téleostéens peuvent être distinguées des autres écailles dermiques connues de Vertébrés inférieurs.
    Notizen: Summary New data on the ultrastructural features of the elasmoid scales ofCarassius auratus have been obtained by use of rapid freezing with subsequent freeze-substitution in anhydrous solvents. These are compared with the results obtained using conventional aqueous fixatives. The external layer of the scales is composed of randomly oriented collagen fibres. In the first stages of mineralization, mineral deposits are located in the interfibrillary substance where dense granules appear to be active sites of mineralization. Spheritic mineralization occurs in this layer. The fibrillary plate is composed of two kinds of collagen fibres. Most of them are organized in lamellae forming the “plywood-like structure”. They are thicker than the so-called “TC fibres”, which are oriented from the basal part towards the superficial layer. These TC fibres are involved in the first stages of mineral deposition in the fibrillary plate where inotropic mineralization occurs. The mineral phase is almost always located in the interfibrillary matrix in both layers of the elasmoid scale. In this respect, teleost scales differ from those described so far in other lower vertebrates.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01258495
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 94
    Digitale Medien
    Digitale Medien
    The ultrastructure of the eye of the mosquitofishGambusia affinis (1982)
    Springer
    Cell & tissue research 223 (1982), S. 431-443 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Eye ; Ultrastructure ; Gambusia affinis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of the tissue components of the eye ofGambusia affinis, excluding the sensory cells, is described. The cornea consists of two different sections of collagenous layers of different density. The choroid includes an argentea composed ofα- andβ-melanophores, lipopterinophores and a choriocapillaris associated with the rete mirabile of the choroid body. Bruch's membrane, underlying the retinal pigment layer, can develop complex associations with fibroblasts delimiting the choriocapillaris. The outer section (stroma) of the iris includes several cell types that are not found in the inner or vitread section. In adultGambusia the lens capsule is well developed, but in twoweek-oldSarotherodon larvae the lens epithelium is covered only by a glycocalyx.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01258500
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 95
    Digitale Medien
    Digitale Medien
    Cytoplasmic organization and quantitation of microtubules in bovine mammary epithelial cells during lactation and involution (1982)
    Springer
    Cell & tissue research 223 (1982), S. 421-430 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Microtubules ; Cattle ; Mammary gland ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Ultrastructural examination of milk secretory cells from lactating bovine mammary gland revealed presence of numerous microtubules in the apical and paranuclear cytoplasm, particularly in the vicinity of Golgi components. Most microtubules were oriented perpendicular to the apical plasma membrane and appeared to form a framework around Golgi dictyosomal elements and secretory vesicles. In comparison, non-secretory cells obtained from involuting glands displayed few microtubules and these were randomly located throughout the cytoplasm with no particular orientation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01258499
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 96
    Digitale Medien
    Digitale Medien
    Apical surface of the epithelial cells in the gallbladder of the rainbow trout and the tench (1982)
    Springer
    Cell & tissue research 224 (1982), S. 449-454 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Gallbladder epithelium ; Brush border ; Apocrine secretion ; Ultrastructure ; Teleosts
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The free surface of the epithelial cells in the gallbladder of the rainbow trout (a predatory fish) and the tench (an omnivorous fish) is characterized by well-developed microvilli. They are irregularly arranged in the tench, but form a true brush border consisting of regularly aligned microvilli in the rainbow trout. In both species membrane-bounded cytoplasmic protrusions, up to 5 μm in diameter, extend from the apical surface. These protrusions are free of granules, secretory vesicles or other organelles; only in the tench some of them contain glycogen. Thus, the previously used terms “apocrine and droplet secretion” are not justified; the epithelial protrusions are now to be regarded as droplets of degenerated cytoplasm. Since they resemble the protrusions reported in fetal and postnatal epithelial cells in the gallbladder of higher vertebrates, interspecific differences are discussed. There is no significant correlation between the seasonal activity of the fish and the abundance or structure of the cytoplasmic protrusions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216886
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 97
    Digitale Medien
    Digitale Medien
    Ultrastructural study of interdigitating cells in the thymus of the spotless starling, Sturnus unicolor (1982)
    Springer
    Cell & tissue research 225 (1982), S. 687-691 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Interdigitating cells ; Thymus ; Birds ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Interdigitating cells (IDC) in the thymus of the spotless starling, Sturnus unicolor, were examined by electron microscopy. They occur principally in the thymic medulla and corticomedullary border. They possess an irregular nucleus and a perinuclear area of cytoplasm, containing most of the membranous organelles, surrounded by a peripheral electron-lucent zone. Clusters of smooth Golgi vesicles and complicated labyrinthine membrane-membrane contacts are the most characteristic cytological features. Birbeck granules are absent. Lymphocytes, plasma cells and even myoid cells can be found embedded in the cytoplasm. Immature elements, intermediate between epithelial-reticular cells and interdigitating cells, are tentatively identified as prointerdigitating cells. The functional significance of IDCs, and their phylogenetic significance in the vertebrate immune system, is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00214813
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 98
    Digitale Medien
    Digitale Medien
    Ultrastructure of the rat median eminence after superfusion (1982)
    Springer
    Cell & tissue research 226 (1982), S. 27-35 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Median eminence ; Ultrastructure ; In vitro systems ; Neurosecretion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Isolated medio-basal hypothalami of adult rats were continuously superfused in a chamber with controllable inputs and outputs, for periods from 30 to 240 min. The median eminence was prepared for transmission electron microscopy under carefully controlled conditions by immersion fixation with osmium tetroxide. The ultrastructure of superfused median eminence was compared with that of directly fixed, non-superfused median eminence. Even after 4h of superfusion, the median eminence displays remarkably well preserved histological and cytological patterns; cytomembranes, cell organelles, intercellular relationships, and extracellular spaces were remarkably similar in superfused and non-superfused tissues. As a consequence of osmium tetroxide fixation, microtubules were not observable. The ultrastructural information obtained from unstimulated rat median eminence superfused in vitro provides a basis for future morphofunctional correlations in the study of neurosecretion.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00217079
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 99
    Digitale Medien
    Digitale Medien
    Ultrastructural changes in the neurohypophysis of the aged male rat (1982)
    Springer
    Cell & tissue research 226 (1982), S. 51-62 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neurohypophysis ; Ultrastructure ; Ageing ; Hormone-containing vesicles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The neurohypophyses (neural lobes of the pituitary) of young adult (3–6 months) and aged (12–30 months) male rats were studied by means of electron microscopy. Stereomorphometric analyses were performed to determine the size, number and relative volume of the hormone-containing vesicles. The principal observations included: 1) the conspicuous depletion in aged rats of the granular hormone-containing vesicles from the axon terminals and the Herring bodies, with a decrease in the relative volume fraction of the vesicles from 4.8 Vv % in the control animals to 1.1 Vv % in the aged rats; 2) a change in the size-distribution of the hormone vesicles; 3) an increase in the extracellular space around the nerve terminals, axons and capillaries; and 4) lipid accumulations and signs of activation in the pituicytes. The possible physiological significance of the findings is discussed in the light of several regulatory functions known to be altered during the process of ageing.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00217081
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 100
    Digitale Medien
    Digitale Medien
    Axon terminals with unusual vesicles in the brain of the polychaete, Ophryotrocha puerilis (1982)
    Springer
    Cell & tissue research 226 (1982), S. 237-240 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Polychaetes ; Neuroendocrine system ; Nerve endings ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the brain of Ophryotrocha puerilis swollen nerve endings filled with electron-lucent vesicles and aggregates of vesicles were observed. The vesicles do not resemble elementary neurosecretory granules. Tests for biogenic amines were negative; no dense-core vesicles were found. The vesicle type described here cannot be related to any of the types thus far found in nerve cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00217098
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...