Impact of broom, Cytisus scoparius (Fabaceae), in naturally treeless sub-alpine frost-hollow vegetation communities at the Barrington Tops, south-eastern Australia

The exotic shrub Cytisus scoparius (L.) Link (family Fabaceae), known as broom, is having a major impact on native vegetation in naturally treeless sub-alpine frost-hollow areas (c. 32o 01’ 37” S, 151o 26’ 12” E’, 1440 m elevation) at the Barrington Tops, New South Wales, in south-eastern Australia. This vegetation is of limited extent and has significant biogeographical and ecological importance. Nine paired 10 m line transects were compared, with one of the pair in areas of almost 100% Cytisus scoparius and the other in adjacent areas without Cytisus scoparius. Results were compared with species recorded from this area in the 1930s. There are obvious differences in native vegetation in areas with and without Cytisus scoparius. On average there were 5.1 (range 2–10) species per 10 m in areas of almost 100% Cytisus scoparius cover and 17.0 (12–25) species per 10 m in areas adjacent to infested areas but without Cytisus scoparius. Other than Cytisus scoparius, the area surveyed had little in the way of exotic species and these were only present at low densities. Native species present in 2008 are similar to those recorded in the 1930s; there were no records of Cytisus scoparius in the area in the 1930s. The study suggests that control of Cytisus scoparius in naturally treeless areas at the Barrington Tops should be a priority to prevent a decline in the distribution and abundance of many plant species, many of which only occur in treeless areas of the Barrington Tops

Testability of a swarm robot using a system of systems approach and discrete event simulation

A simulation framework using discrete event system specification (DEVS) and data encoded with Extensible Markup Language (XML) is presented to support agent-in-the-loop (AIL) simulations for large, complex, and distributed systems. A System of Systems (SoS) approach organizes the complex systems hierarchically. AIL simulations provide a necessary step in maintaining model continuity methods to achieve a greater degree of accuracy in systems analysis. The proposed SoS approach enables the simulation and analysis of these independent and cooperative systems by concentrating on the data transferred among systems to achieve interoperability instead of requiring the software modeling of global state spaces. The information exchanged is wrapped in XML to facilitate system integration and interoperability. A Groundscout is deployed as a real agent working cooperatively with virtual agents to form a robotic swarm in an example threat detection scenario. This scenario demonstrates the AIL framework\u27s ability to successfully test a swarm robot for individual performance and swarm behavior. Results of the testing process show an increase of robot team size increases the rate of successfully investigating a threat while critical violations of the algorithm remained low despite packet loss

Plant species first recognised as naturalised for New South Wales in 2002 and 2003, with additional comments on species recognised as naturalised in 2000–2001

Information is provided on the taxonomy and distribution of 71 taxa of naturalised or naturalising plants newly recorded for the state of New South Wales during the period 1 January 2002 to 31 December 2003. Of these taxa, 32 are new records for Australia (prefaced with a †). These species are: Abutilon pictum, Acanthus mollis, †Aesculus indica (naturalising), Agapanthus praecox subsp. orientalis, Ajuga reptans, †Anigozanthos flavidus, Aquilegia vulgaris, Arbutus unedo, †Athertonia diversifolia (naturalising), †Bergenia x schmidtii (naturalising), Bromus catharticus subsp. stamineus, Bryophyllum daigremontianum, Bryophyllum fedtschenkoi, Calyptocarpus vialis, †Ceiba speciosa (naturalising), Cereus uruguayanus, †Cestrum x cultum, †Chamaecyparis lawsoniana, Cistus salviifolius, †Clematis montana, †Coprosma x cunninghamii, Coprosma robusta, Cornus capitata, Cotoneaster simonsii, Cotoneaster x watereri group, Crinum moorei, Cupressus lusitanica, †Cylindropuntia fulgida var. mamillata forma monstrosa, †Cylindropuntia prolifera, Cylindropuntia tunicata, Desmanthus virgatus, Drosanthemum candens, †Elaeagnus umbellata (naturalising), †Eragrostis trichophora, †Eupatorium lindleyanum, †Gibasis pellucida, Glechoma hederacea, †Hesperis matronalis, Hieracium aurantiacum subsp. carpathicola, †Inga edulis (naturalising), †Juniperus conferta (naturalising), †Justicia caudata, Lamium galeobdolon, Lathyrus tingitanus, †Lysimachia fortunei, †Maackia amurensis, †Monstera deliciosa, †Murdannia keisak, Odontonema tubaeforme, Oxalis vallicola, Phoenix canariensis, †Physostegia virginiana, Pinus patula, Pittosporum eugenioides, †Pittosporum ralphii, Pittosporum tenuifolium, Plectranthus ecklonii, †Potentilla vesca, †Prunus campanulata, †Rhododendron ponticum, Rosa luciae, Rubus rugosus, Ruellia squarrosa, †Senna multijuga, Stapelia gigantea, Stephanophysum longifolium, Strobilanthes anisophylla, †Tabebuia chrysotricha, †Tabebuia impetiginosa, †Tradescantia pallida and Ulmus x hollandica. Additional notes and name changes are recorded for plants first recognised as naturalised for New South Wales over the period 2000–2001. The identification of several naturalised taxa occurring in New South Wales has been corrected. Plants formerly identified as Pinus nigra var. corsicana are now considered to be Pinus halepensis; Cylindropuntia arbuscula is Cylindropuntia kleiniae, Cylindropuntia tunicata is Cylindropuntia rosea, Abrus precatorius subp. precatorius is now Abrus precatorius subsp. africanus and Cotoneaster ?horizontalis is Cotoneaster microphyllus. Further field studies have revealed that Cylindropuntia leptocaulis, Cylindropuntia spinosior, Hypericum kouytchense and Chamaesyce ophthalmica are more widespread than previously thought

Osteoporosis therapy: an example of putting evidence-based medicine into clinical practice

A major aim of evidence-based medicine is to assist clinical decision-making by providing the most current and reliable medical information. Systematic reviews and meta-analyses are important tools in this process. Systematic reviews identify and compile relevant evidence, while meta-analyses summarize and quantify the results of such reviews. Results from meta-analyses are, at present, the main source of summary evidence for the efficacy of treatments for a specific condition. They are important tools for helping to choose among treatment options, although they cannot be used to directly compare the magnitude of the effect of various therapies. However, the methods used and the consequent clinical value of the results, may be poorly understood by clinicians, who may therefore not take full advantage of the evidence. Recently, a panel of experts in osteoporosis and evidence-based medicine applied rigorous, validated, scientific standards to produce a systematic review and meta-analysis of randomized controlled trials of anti-resorptive agents used to treat osteoporosis. They found that, although several agents reduced the risk of vertebral fracture, only two, alendronate and risedronate, demonstrated convincing evidence for both non-vertebral and vertebral fracture risk reductions. The clinical implication of these results is that there are important differences in anti-fracture efficacy among currently available agents. In the absence of evidence from head-to-head clinical trials and because of the systematic nature and methodological rigor of the analyses, these data provide important information for clinical decision-makin

A SOCIAL COST-BENEFIT ANALYSIS OF A SMALL-SCALE CLAM FISHERY IN THE EASTERN CAPE, SOUTH AFRICA

When a proposal was advanced in 1991 to harvest the wedge clam Donax serra in the Eastern Cape, South Africa, for commercial gain, it elicited a huge public outcry. In order to shed light on the issue, a social costbenefit analysis (CBA), based on a biologically sustainable extraction rate of 100 ton of clams per year, was carried out on its commercial exploitation. Because fishery activities might exact a price on society in the form of negatively altering the quality of people\'s recreation experience in the area, as well as damage the aesthetic and ecological attributes of the beach system, such external effects were identified and valuated. Results from the CBA yielded positive net present values (NPVs) for project options involving live clams being sold on the export market (to Hong Kong) for R24.70 kg-1 and negative NPVs for domestic market options (Johannesburg and Cape Town), where the clam would be sold for R6.50 kg-1. Assuming a discount rate of 8&#37, the highest NPV was obtained for the scenario in which total production was sold on the foreign market and the firm rented facilities of an existing organization. The external cost was the single largest component of the cost of the fishery. The conclusion drawn is that the social benefit of the project exceeds the social cost – a conclusion which supports commercial exploitation of clam stocks along the St Francis Bay beach, but one which does not include the osts associated with policing.Afr. J. mar. Sci. 25: 159–16

Effects of oilseed meal and grain-urea supplements fed infrequently on digestion in sheep: 1. Low quality grass hay diets

An experiment examined intake, growth response and rumen digestion of young sheep fed ad libitum low quality grass hay alone or supplemented with approximately isonitrogenous amounts of barley grain and urea (Bar/N), safflower meal (SAF) or linseed meal (LIN) provided at 3 days intervals. Supplements comprised 13–20% of total DM intake. Sheep fed grass hay alone consumed 60.2gDM/kgLW0.75/day of hay and an estimated 6.09MJ metabolizable energy (ME)/day, and were in liveweight (LW) maintenance. Hay intake was decreased (P<0.05) by the Bar/N supplement with a substitution rate of 0.9, but was not changed by the oilseed meal supplements. Each of the supplements increased (P<0.05) estimated ME intake to a similar extent, but LW gain and wool growth were lower (P<0.05) in sheep supplemented with Bar/N than those supplemented with LIN. Rumen degradabilities of the SAF and LIN CP were estimated to be 0.72 and 0.62, respectively. Rumen ammonia concentrations in sheep fed hay alone (average 97mgNH3/l) were expected to be adequate for microbial activity. Fractional outflow rate (FOR) of liquid from the rumen measured with Co-EDTA (mean 0.109h−1) was greater than that of Cr-mordanted supplements (mean 0.056h−1), which was in turn greater than the FOR of Cr-mordanted hay (mean 0.031h−1). Diet did not affect these FOR. Supplemented sheep accommodated increased DM intake on Day 1 of the 3 day supplementation cycle by increasing rumen digesta load rather than by increasing rate of passage of digesta. Results show that the LW gain of young sheep fed low quality hay was increased more by either oilseed meal than by equivalent amounts of barley grain/urea supplement, apparently due to more efficient utilization of ME for LW gain

Twentieth century increase in snowfall in coastal West Antarctica

The Amundsen Sea sector of the West Antarctic ice sheet has been losing mass in recent decades; however, long records of snow accumulation are needed to place the recent changes in context. Here we present 300 year records of snow accumulation from two ice cores drilled in Ellsworth Land, West Antarctica. The records show a dramatic increase in snow accumulation during the twentieth century, linked to a deepening of the Amundsen Sea Low (ASL), tropical sea surface temperatures, and large-scale atmospheric circulation. The observed increase in snow accumulation and interannual variability during the late twentieth century is unprecedented in the context of the past 300 years and evidence that the recent deepening of the ASL is part of a longer trend