4,118 research outputs found

    An ecological study of Chinese privet (Ligustrum sinense Lour.) in the Waikato Region

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    Chinese privet (Ligustrum sinense) has naturalised across the Waikato region invading lowland native forest and wetland habitat. This shrub has the ability to form a dense canopy or subcanopy and appears to exclude other native species from establishing in the understorey. Chinese privet seedlings were found in abundance underneath privet canopy, where they grow slower than when invading a new site yet are able to succeed adult plants and continually occupy a site. Chinese privet seedlings establish readily under intact native canopy but are more prolific in disturbed high light environments. Fruit is produced in abundance and is dispersed by birds particularly beneath perch sites, which limits seed dispersal over open ground. Chinese privet seedlings appear to be palatable to stock, but rapidly out-compete and dominate regenerating native species when grazing pressure is removed. A short-lived seedbank, six months to one year viability, suggests that the removal of adult plants will quickly reduce the number of seedlings establishing. This invasive shrub is a serious weed in south-eastern USA where it is well established and would appear to have similar potential in New Zealand to form vast, dense thickets with very low floristic diversity

    Waiwhakareke Restoration Plantings: Establishment of Monitoring Plots 2005-06

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    Waiwhakareke Natural Heritage Park is being developed to reconstruct native lowland and wetland ecosystems as were once widespread in the Waikato Region. The 60ha Natural Heritage Park is located on the north-west outskirts of Hamilton City and includes a peat lake (Horseshoe Lake) which is surrounded by introduced willow trees. There is some native marginal vegetation around the lake, including rushes and sedges, and an extensive area of gently sloping pasture completes the catchment. The restoration and recreation of the native plant and animal communities is being lead by the Hamilton City Council in partnership with The University of Waikato, Wintec, Nga Mana Toopu o Kirikiriroa Limited Resource Management and Cultural Consultants and Tui 2000 (McQueen 2005; McQueen & Clarkson 2003)

    An application of software design and documentation language

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    The software design and documentation language (SDDL) is a general purpose processor to support a lanugage for the description of any system, structure, concept, or procedure that may be presented from the viewpoint of a collection of hierarchical entities linked together by means of binary connections. The language comprises a set of rules of syntax, primitive construct classes (module, block, and module invocation), and language control directives. The result is a language with a fixed grammar, variable alphabet and punctuation, and an extendable vocabulary. The application of SDDL to the detailed software design of the Command Data Subsystem for the Galileo Spacecraft is discussed. A set of constructs was developed and applied. These constructs are evaluated and examples of their application are considered

    Does the Foundational Model of Anatomy Ontology Provide a Knowledge Base for Learning and Assessment in Anatomy Education?

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    Throughout the development of the Foundational Model of Anatomy (FMA) ontology, one of the use cases put forth has been anatomy education. In this work, we examine which types of knowledge taught to anatomy students can be supported by the FMA knowledge base. We first categorize types of anatomical knowledge, then express these patterns in the form “Given ____, state ____”. Each of the 33 patterns was evaluated for whether this type of knowledge is compatible with the modeling and scope of the FMA

    Eguchi-Hanson Solitons in Odd Dimensions

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    We present a new class of solutions in odd dimensions to Einstein's equations containing either a positive or negative cosmological constant. These solutions resemble the even-dimensional Eguchi-Hanson-(A)dS metrics, with the added feature of having Lorentzian signatures. They are asymptotic to (A)dSd+1/Zp_{d+1}/Z_p. In the AdS case their energy is negative relative to that of pure AdS. We present perturbative evidence in 5 dimensions that such metrics are the states of lowest energy in their asymptotic class, and present a conjecture that this is generally true for all such metrics. In the dS case these solutions have a cosmological horizon. We show that their mass at future infinity is less than that of pure dS.Comment: 26 pages, Late

    Optically pure heterobimetallic helicates from self-assembly and click strategies

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    Single diastereomer, diamagnetic, octahedral Fe(II) tris chelate complexes are synthesised that contain three pendant pyridine proligands pre-organised for coordination to a second metal. They bind Cu(I) and Ag(I) with coordination geometry depending on the identity of the metal and the detail of the ligand structure, but for example homohelical (ΔFe,ΔCu) configured systems with unusual trigonal planar Cu cations are formed exclusively in solution as shown by VT-NMR and supported by DFT calculations. Similar heterobimetallic tris(triazole) complexes are synthesised via clean CuAAC reactions at a tris(alkynyl) complex, although here the configurations of the two metals differ (ΔFe,ΛCu), leading to the first optically pure heterohelicates. A second series of Fe complexes perform less well in either strategy as a result of lack of preorganisation

    SS433:the microquasar link with ULXs?

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    SS433 is the prototype microquasar in the Galaxy and may even be analogous to the ULX sources if the jets' kinetic energy is taken into account. However, in spite of 20 years of study, our constraints on the nature of the binary system are extremely limited as a result of the difficulty of locating spectral features that can reveal the nature and motion of the mass donor. Newly acquired, high resolution blue spectra taken when the (precessing) disc is edge-on suggest that the binary is close to a common-envelope phase, and hence providing kinematic constraints is extremely difficult. Nevertheless, we do find evidence for a massive donor, as expected for the inferred very high mass transfer rate, and we compare SS433's properties with those of Cyg X-3.Comment: 4 pages, 3 figures, to appear in "Compact binaries in the Galaxy and beyond

    Symmetries of a class of nonlinear fourth order partial differential equations

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    In this paper we study symmetry reductions of a class of nonlinear fourth order partial differential equations \be u_{tt} = \left(\kappa u + \gamma u^2\right)_{xx} + u u_{xxxx} +\mu u_{xxtt}+\alpha u_x u_{xxx} + \beta u_{xx}^2, \ee where α\alpha, β\beta, γ\gamma, κ\kappa and μ\mu are constants. This equation may be thought of as a fourth order analogue of a generalization of the Camassa-Holm equation, about which there has been considerable recent interest. Further equation (1) is a ``Boussinesq-type'' equation which arises as a model of vibrations of an anharmonic mass-spring chain and admits both ``compacton'' and conventional solitons. A catalogue of symmetry reductions for equation (1) is obtained using the classical Lie method and the nonclassical method due to Bluman and Cole. In particular we obtain several reductions using the nonclassical method which are no} obtainable through the classical method

    New exact fronts for the nonlinear diffusion equation with quintic nonlinearities

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    We consider travelling wave solutions of the reaction diffusion equation with quintic nonlinearities ut=uxx+μu(1u)(1+αu+βu2+γu3)u_t = u_{xx} + \mu u (1 -u ) ( 1 +\alpha u + \beta u^2 +\gamma u^3). If the parameters α,β\alpha , \beta and γ\gamma obey a special relation, then the criterion for the existence of a strong heteroclinic connection can be expressed in terms of two of these parameters. If an additional restriction is imposed, explicit front solutions can be obtained. The approach used can be extended to polynomials whose highest degree is odd.Comment: Revtex, 5 page
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