Role of plant functional traits in determining vegetation composition of abandoned grazing land in north-eastern Victoria, Australia

Question: In the Northern Hemisphere, species with dispersal limitations are typically absent from secondary forests. In Australia, little is known about dispersal mechanisms and other traits that drive species composition within post-agricultural, secondary forest. We asked whether mode of seed dispersal, nutrient uptake strategy, fire response, and life form in extant vegetation differ according to land-use history. We also asked whether functional traits of Australian species that confer tolerance to grazing and re-colonisation potential differ from those in the Northern Hemisphere. Location: Delatite Peninsula, NE Victoria, Australia. Methods: The vegetation of primary and secondary forests was surveyed using a paired-plot design. Eight traits were measured for all species recorded. ANOSIM tests and Non-metric Multi-dimensional Scaling were used to test differences in the abundance of plant attributes between land-use types. Results: Land-use history had a significant effect on vegetation composition. Specific leaf area (SLA) proved to be the best predictor of response to land-use change. Primary forest species were typically myrmecochorous phanerophytes with low SLA. In the secondary forest, species were typically therophytes with epizoochorous dispersal and high SLA. Conclusions: The attributes of species in secondary forests provide tolerance to grazing suggesting that disturbance caused by past grazing activity determined the composition of these forests. Myrmecochores were rare in secondary forests, suggesting that species had failed to re-colonise due to dispersal limitations. Functional traits that resulted in species loss through disturbance and prevented re-colonisation were different to those in the Northern Hemisphere and were attributable to the sclerophyllous nature of the primary forest

Partial Core Transformer for Energization of High Voltage Arc-Signs

paper T3-304A high voltage partial core resonating transformer has been designed and constructed such that its magnetising current reactance is matched to the reactive current drawn by the capacitance of an arc-sign. The supply only provides the real power losses of the transformer plus any reactive power mismatch between the magnetizing reactance and the capacitance of the arc-sign. A mathematical model of the transformer is developed using a reverse design modelling technique. The model is then used to design a 50Hz, 8kVA, 230V/80kV, partial core transformer to meet the required electrical demand of the load. The transformer was constructed and tested. The transformer successfully resonated with the load and provided 68VAr of compensation when operating at 10kV while being supplied from a domestic 230V, 10A, power outlet. The completed transformer has a finished weight of 69kg and has been successfully used for powering an arc-sign at an exhibition of electric sculptures

Lattice Kinetics of Diffusion-Limited Coalescence and Annihilation with Sources

We study the 1D kinetics of diffusion-limited coalescence and annihilation with back reactions and different kinds of particle input. By considering the changes in occupation and parity of a given interval, we derive sets of hierarchical equations from which exact expressions for the lattice coverage and the particle concentration can be obtained. We compare the mean-field approximation and the continuum approximation to the exact solutions and we discuss their regime of validity.Comment: 24 pages and 3 eps figures, Revtex, accepted for publication in J. Phys.

Denominator identities for finite-dimensional Lie superalgebras and Howe duality for compact dual pairs

We provide formulas for the denominator and superdenominator of a basic classical type Lie superalgebra for any set of positive roots. We establish a connection between certain sets of positive roots and the theory of reductive dual pairs of real Lie groups. As an application of our formulas, we recover the Theta correspondence for compact dual pairs. Along the way we give an explicit description of the real forms of basic classical type Lie superalgebras.Comment: Latex, 75 pages. Minor corrections. Final version, to appear in the Japanese Journal of Mathematic

Towards quantitative computed tomography

Computed tomography is introduced along with an overview of its diverse applications in many scientific endeavours. A unified approach for the treatment of scattering from linear scalar wave motion is introduced. The assumptions under which wave motion within a medium can be characterised by concourses of rays are presented along with comment on the validity of these assumptions. Early and conventional theory applied for modelling the behaviour of rays, within media for which ray assumptions are valid, are reviewed. A new computerised method is described for reconstruction of a refractive index distribution from time-of-flight measurements of radiation/waves passing through the distribution and taken on a known boundary surrounding it. The reconstruction method, aimed at solving the bent-ray computed tomography (CT) problem, is based on a novel ray description which doesn't require the ray paths to be known. This allows the refractive index to be found by iterative solution of a set of linear equations, rather than through the computationally intensive procedure of ray tracing, which normally accompanies iterative solutions to problems of this type. The preliminary results show that this method is capable of handling appreciable spatial refractive index variations in large bodies. A review containing theory and techniques for image reconstruction from projections is presented, along with their historical development. The mathematical derivation of a recently developed reconstruction technique, the method of linograms is considered. An idea, termed the plethora of views idea, which aims to improve quantitative CT image reconstruction, is introduced. The theoretical foundation for this is the idea that when presented with a plethora of projections, by which is meant a number greater than that required to reconstruct the known region of support of an image, so that the permissible reconstruction region can be extended, then the intensity of the reconstructed distribution should be negligible throughout the extended region. Any reconstruction within the extended region, that departs from what would be termed negligible, is deduced to have been caused by imperfections of the projections. The implicit expectation of novel schemes which are presented for improving CT image reconstruction, is that contributions within the extended region can be utilised to ameliorate the effects of the imperfections on the reconstruction where the distribution is known to be contained. Preliminary experimental results are reported for an iterative algorithm proposed to correct a plethora of X-ray CT projection data containing imperfections. An extended definition is presented for the consistency of projections, termed spatial consistency, that incorporates the region with which the projection data is consistent. Using this definition and an associated definition, spatial inconsistency, an original technique is proposed and reported on for the recovery of inconsistencies that are contained in the projection data over a narrow range of angles

Migration potential as a new predictor of long-distance dispersal rate for plants

How biotic and abiotic factors interact to shape the overall pattern of dispersal of propagules is critical in understanding the evolution of dispersal mechanisms as well as predicting dispersal rates between patchily-distributed habitats. But which plant traits, demographic and/or habitat factors best predict the capacity for dispersal? We introduce the concept of migration potential (v), a readily interpretable parameter that combines recruitment efficiency (recruits per adult / seeds per adult per dispersal cycle) with level of habitat occupancy for predicting effective long-distance dispersal (LDD) of seeds. Using our empirical (genotype assignment) estimates of LDD and statistics on life-history traits and demographic features for contrasting co-occurring shrub species as a test case, and comparing alternative plant traits, we demonstrate that rate of LDD is best described as a simple function of v. As the direct consequence of life-history and demographic traits in a specific environmental context, v has the potential to predict LDD rates in both stable and changing ecosystems

Defining forgiveness: Christian clergy and general population perspectives.

The lack of any consensual definition of forgiveness is a serious weakness in the research literature (McCullough, Pargament &amp; Thoresen, 2000). As forgiveness is at the core of Christianity, this study returns to the Christian source of the concept to explore the meaning of forgiveness for practicing Christian clergy. Comparisons are made with a general population sample and social science definitions of forgiveness to ensure that a shared meaning of forgiveness is articulated. Anglican and Roman Catholic clergy (N = 209) and a general population sample (N = 159) completed a postal questionnaire about forgiveness. There is agreement on the existence of individual differences in forgiveness. Clergy and the general population perceive reconciliation as necessary for forgiveness while there is no consensus within psychology. The clergy suggests that forgiveness is limitless and that repentance is unnecessary while the general population suggests that there are limits and that repentance is necessary. Psychological definitions do not conceptualize repentance as necessary for forgiveness and the question of limits has not been addressed although within therapy the implicit assumption is that forgiveness is limitless.</p

Strategies and tactics for local market making in the Temporary Staffing Industry

This paper examines the increasing complexity of interactions between temporary staffing agencies and their client firms within the local labour market of Birmingham, UK. Temporary Staffing Agencies have been identified as active and influential agents in local, national and international labour markets. Their influence on local labour market functioning, national labour regulation and international regulatory frameworks is growing. Existing literature demonstrates the power of large multinational temporary staffing agencies in both established and emerging temporary staffing markets. Such analyses also contend that multinational agencies operate in very different ways to smaller independent ‘back-street’ temporary staffing agencies, with different types of clients and at different ends of the market. However, the research conducted in Birmingham, UK suggests that the reality is more complex. It is argued that there can be more subtle and intricate nuances of relevance to the temporary staffing industry in respect of the relationships that exist between large and small temporary staffing agencies, as well as between such agencies and their clients. We highlight how smaller agencies in Birmingham are utilising a variety of strategies and tactics to creatively ‘bolt-on’ to more formalised national agreements established by multinational agencies with their clients. Moreover, smaller agencies – in some instances – are able to exploit their knowledge of local labour markets to subvert, sabotage and/or infiltrate the activities of multinational agencies in increasingly astute ways. In turn, this generates a series of questions for understanding the nature of ‘market making’ associated with the temporary staffing industry more broadly

Multi-netclust: an efficient tool for finding connected clusters in multi-parametric networks

Summary: Multi-netclust is a simple tool that allows users to extract connected clusters of data represented by different networks given in the form of matrices. The tool uses user-defined threshold values to combine the matrices, and uses a straightforward, memory-efficient graph algorithm to find clusters that are connected in all or in either of the networks. The tool is written in C/C++ and is available either as a form-based or as a command-line-based program running on Linux platforms. The algorithm is fast, processing a network of > 106 nodes and 108 edges takes only a few minutes on an ordinary computer

The Morphological Effects of Two Antimicrobial Peptides, Hecate-1 and Melittin, on Escherichia Coli

The effects of the 26 amino acid, cationic, amphipathic, antibacterial peptide melittin and hecate-1, a 23 amino acid analog of it, on the gram negative bacterium Escherichia coli were investigated using scanning electron microscopy (SEM), transmission electron micros-copy (TEM), and freeze-fracture. Both peptides killed virtually all bacteria at the peptide concentration and cell density used. TEM and SEM revealed aggregates of bacteria entangled with material extruded from the bacterial surfaces. SEM revealed irregular bacterial surfaces with bleb-like projections. TEM and freeze-fracture indicate that the bacterial inner and outer membranes, as well as the peptidoglycan layer between, were extensively damaged. The cytoplasmic contents of the cells, however, did not appear radically disturbed, providing little evidence for osmotically induced cytolysis