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  • 1
    Electronic Resource
    Electronic Resource
    Medial septal projections to the dentate gyrus of the rat: electrophysiological analysis of distribution and plasticity (1984)
    Springer
    Experimental brain research 56 (1984), S. 243-256 
    Details
    ISSN: 1432-1106
    Keywords: Medial septum ; Hippocampus ; Dentate gyrus ; Evoked potentials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Previous electrophysiological experiments in rabbits have suggested that medial septal stimulation activates dentate granule cells and evokes an associated negative field response at the granule cell layer, without an associated “dendritic” response. Anatomical studies have suggested that septal input to the granule cells may be to stratum moleculare, or close to the cell layer, or may not exist at all. The present experiments confirmed in rats anaesthetised with urethane that medial septal stimulation elicits single action potentials from cells in the granule layer. The associated negative field potential was maximal in the granule cell layer and there was no sign of a separate dendritic potential. The fibres responsible for this potential travel to the dorsal hippocampus in the fornix superior rather than the fimbria, taking the same course as the fibres which contribute to the dense cholinesterase staining just above the granule cell layer. Stimulation at 100 Hz for 1 s of either medial septal, or perforant path, input to the dentate granule cell layer produced long term potentiation of the subsequent evoked field responses to the stimulated pathway. The responses to the non-stimulated pathway were unchanged. Paired pulse stimulation produced both homosynaptic and heterosynaptic potentiation. These data suggest that medial septal input synapses close to granule cell bodies and produces a negative field potential which is a combination of dendritic and population spike potentials. Medial septal input also appeared to produce direct activation of hilar neurones, some of which may be basket cells or other interneurones. The data also show that long term potentiation is specific to this input, perhaps dependent on presynaptic mechanisms. Paired pulse potentiation, at least in the heterosynaptic case appears to depend on postsynaptic mechanisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236280
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  • 2
    Electronic Resource
    Electronic Resource
    Petrov-Galerkin finite element methods with a hinged test space for singularly perturbed problems (1985)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 21 (1985), S. 1803-1812 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In this paper we introduce finite element methods of Petrov-Galerkin type for the approximate solution of two-point boundary-value problems for singularly perturbed, second-order, ordinary, linear differential equations. We write down Petrov-Galerkin methods on a uniform mesh which have asymptotic error estimates, as the mesh size tends to zero, whose magnitude is independent of the singular perturbation parameter. This is in marked contrast to standard finite element methods which do not possess such a property on a uniform mesh. For these, typically, the error on a fixed uniform mesh blows up as the singular perturbation parameter tends to zero.This robust behaviour of these Petrov-Galerkin methods for singularly perturbed problems is achieved by choosing trial spaces of standard piecewise polynomial type, while the test spaces consist of hinged piecewise polynomials.We consider self-adjoint and non-self-adjoint two-point boundary-value problems with Dirichlet boundary conditions. We define hinged test spaces for both types of problem. We then introduce a number of sample problems and we present numerical solutions of these sample problems using a Petrov-Galerkin method with the appropriate hinged test space.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620211007
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  • 3
    Electronic Resource
    Electronic Resource
    Dispersal ofAleochara bilineata [Col.: Staphylinidae] following inundative releases in urban gardens (1992)
    Springer
    BioControl 37 (1992), S. 55-63 
    Details
    ISSN: 1573-8248
    Keywords: Staphylinidae ; Aleochara bilineata ; beneficial arthropods ; dispersal ; predation ; biological control ; arthropodes utiles ; dissémination ; prédation ; lutte biologique ; Staphylinidae ; Aleochara bilineata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Résumé Aleochara bilineata (Gyllenhal) [Coleoptera: Staphylinidae] est un prédateur et un parasite courants de la mouche des racines [Diptera: Anthomyiidae] dans les cultures commerciales et les jardins potagers. Pour évaluer l'activité de dissémination deA. bilineata dans les jardins potagers, on a lâché des coléoptères marqués à raison de 0 et de 1000 en 1987, et de 0, 250, 500, et 1000/jardin potager/semaine en 1988. Trois pour cent des coléoptères ainsi marqués ont été recapturés dans les jardins potagers d'origine. Les populations naturelles deA. bilineata sont très faibles dans tous les jardins potagers et on ne constate aucune augmentation décelable de 1987 à 1988. Les recaptures sont proportionnelles aux taux de lâchers. On n'observe aucune différence significative dans les taux de recapture entre les sexes. Les recaptures et les distributions non uniformes deA. bilineata marqués dans les jardins potagers révèlent qu'ils ont pu voler au moins à 5 km de distance dans les conditions urbaines et choisir certains jardins plutôt que d'autres comme emplacements propices à l'accouplement, la quête de nourriture et l'oviposition.
    Notes: Abstract Aleochara bilineata (Gyllenhal) [Coleoptera: Staphylinidae] is a common predator and endoparasite of root maggot [Diptera: Anthomyiidae] in both commercial crops and home gardens. To test dispersal activity ofA. bilineata in home gardens, marked beetles were released at rates of 0 and 1,000 in 1987 and 0, 250, 500, and 1,000/gardens/wk in 1988. Three percent of marked beetles were recaptured in release gardens. NaturalA. bilineata populations were very small in all gardens, and there was no detectable increase from 1987 to 1988. Recaptures were proportional to release rates. There was no significant difference in recapture rates between sexes. Recaptures and non-uniform distributions of markedA. bilineata in control gardens revealed that they were capable of flying at least 5 km under urban conditions, and of selecting particular gardens as suitable mating, foraging, and oviposition sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02372974
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    Paper (German National Licenses)
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