RONSE DECRAENE, L.-P. AND AKEROYD, J. R., 1988. Generic limits in Polygonurn and related genera (Polygonaceae) on the basis of floral characters. In order to investigate the taxonomic value of a number of characters in the elucidation of relationships within the collective genus Polygonurn L., and segregate genera Atraphaxis L., Calligonum L., Pteropyrum Jaub. & Spach., Oxygonurn Burch., Fagofivrurn Mill., Hnrpagocarpus Hutch. & Dandy and Polygonella Michx., 83 species of the tribe Polygoneae emend. Jaretzky were studied. The following floral characters were examined: stamen number, insertion and external morphology; structure and morphology of the floral nectaries; vasculature and surface morphology of the tepals. Problems i n floral morphology in Polygonaceae are discussed, together with relationships within the Family. l'he tribal division proposed by Haraldson (1978) is supported, but a new and different delimitation of genera is proposed. The present data support a division of Polygonurn L. sensu lalo and its related taxa into two tribes: Polygoneae (containing Polygonum L. sensu slriclo, Fallopia Adans., Oxygonum Burch., Pterofivrum Jaub. & Sparh., Atraphaxis L. and Calligonum L.), and Persicarieae (containing Fagopyrurn Mill., Harpagocarpus Hutch. & Dandy, Persicaria Mill. and Koenigia L.). The genus Reynoulria Houtt. is included as a section of Fallopia Adans.; Bislorla Mill,, Aconogonon Reirhenb. and Touara Adans. are included within Persicaria Mill. A number of new combinations are proposed in Persicaria and Fallopia.
Purpose-To provide a review of the interface between e-learning, digital libraries and learning content. Design/methodology/approach-A review of current thinking and activity surrounding the delivery of content in e-learning systems. Some analysis of information concerns and commentary on future scenarios. Findings-The paper investigates the reality of information management in e-learning practice. It looks at types of information extant in systems and analyses links between (virtual) learning environments, digital libraries and web content. It examines the potential for reuse of material in a university context and the supporting standards and technology. Research limitations/implications-Looks particularly at UK and US context but also has an international dimension. Originality/value-It brings together a disposable set of issues to provide a discursive but practical summary of the topic. It will be of value to an information manager faced with managing content in a learning organisation. Keywords Computer based learning, Learning, Information management, Open systems Paper type Conceptual paper E-learning now E-learning is an ill-defined concept, subject to wide variation in practice, but which nevertheless has become an established component of education delivery worldwide. At one extreme it implies the use of the web technology to facilitate the whole cycle of learning from initial sign-on to final certification, with a range of operations in between, and with no, or little, physical interaction with the host university. This replicates the distance learning model and has parallels with the operations of distance learning universities, which sprang up in the 1960s, though they too had earlier roots in the external degrees of the major UK universities. At the other extreme, and much more commonly, e-learning in many university and college contexts is a hybrid of "traditional" face-to-face teaching, with electronic delivery of content and services built on and, where appropriate, with administration and related tasks also being web based-so called blended learning, in a mixture of the old and new. It has also been correctly described as a process and not as a technology or a product. But to enable these interactions, generic systems have been developed virtual learning environment (VLEs) in the UK, and learning management system (LMS) in the USA which provide a technological, parameter driven framework to allow individual academics to develop and deliver learning content, to interact with students and to
Abstract.In this article we construct a Jordan arc T in the complex plane, with endpoints 0 and 1, such that the polynomials are dense in the Hardy space //2(D\r); D:= {z e C : \z\ < 1} . In order to minimize technical details we do much of our work on a particular "annular" region which has rectilinear boundary. For the rest of the paper let E = {z = x+iy : 1 < max{|x|, \y\} < 2}, S = {z = x+iy : max{|jsc|, \y\} = 1}, and T -{z = x + iy : max{|x|, \y\} -2}. Let us say that a Jordan arc Y := It is well known that if
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