A land resource survey of the Fall Point coastline, Broome, W.A.

The purpose of this study was to find a suitable location for a bird observatory and provide adequate coastal land resource data for the area. The main selection criteria and conditions were: the location was closely adjacent to major wader roosting and feeding sites; all-seasons access was required; the location provided a site of around 2 1/2 hectares to provide space for one or more buildings, camp ground and associated facilities ; anticipated access tracks, site developments and levels of use

Rangeland surveys : a basis for improved land use

In mis 1988, the Department of Agriculture started a three-year programme to assist pastoralists in the Murchison River catchment to update land management planning of their stations. This Project, which is funded by the National Soil Conservation Program, will use interim results from a recent rangeland survey which has investigated and mapped the grazing recources throughout the region. Elsewhere in Western Australia\u27s pastoral areas, information on the productive potential of each area - and the management problems inherent for each class of land - are being used to help pastoral managers of Soil Conservation Districts rehabilitate degraded areas. This information will also encourage them to adopt management practices that conserve the land and improve the long-term economic performance of the grazing enterprise

Inhibition of interleukin-1β-stimulated collagenase and stromelysin expression in human tendon fibroblasts by epigallocatechin gallate ester

The medicinal benefits of green tea (Camellia sinensis) consumption have been attributed to bioavailable polyphenols, notably epigallocatechin gallate (EGCG). We have assessed the effects of EGCG and its non-esterified counterpart EGC on the expression of the collagenases, matrix metalloproteinases (MMP)-1 and -13, and the stromelysin, MMP-3, in human tendon-derived fibroblasts. Interleukin (IL)-1ß increased MMP-1, -3 and -13 mRNA and output at least 30-fold. EGCG reduced this stimulation, by 20–30% at 2.5 µM and more than 80% at 25 µM, and had a smaller effect on MMP-2 mRNA expression, which was not stimulated by IL-1ß. In all experiments EGCG was at least 10-fold more potent than EGC. EGCG reduced the stimulation of p54 JNK/SAPK phosphorylation by IL-1ß but did not affect p38 MAPK phosphorylation, the degradation of I?B or the activating phosphorylation of NF?B. We conclude that EGCG reduces the IL-1-stimulated expression of both collagenase and stromelysin mRNA species, an effect which may be mediated by inhibition of the JNK/SAPK pathway. Taken together with previous reports of EGCG effects on the expression and/or activity of gelatinases and aggrecanases, our results underline the importance of extracellular matrix breakdown as a potential target for the actions of green tea polyphenols

An inventory and condition survey of rangelands in the Carnarvon Basin, Western Australia

The inventory and condition survey of rangelands in the Carnarvon Basin, undertaken by the Department of Agriculture and Food, Western Australia (DAFWA) between 1980 and 1982, describes and maps the natural resources of the region’s pastoral leasehold land. This survey report provides a baseline record of the existence and condition of the natural area’s resources, to assist with the planning and implementation of land management practices. The report identified and described the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assessed the impact of pastoralism and made land management recommendations. The area surveyed covers about 74 500km² in the Carnarvon Basin and Shark Bay regions, and includes the catchments of the Lyndon and Minilya rivers and the lower reaches of the Gascoyne and Wooramel Rivers. The vegetation of the Carnarvon Basin area is mainly dominated by perennial shrubs. A small number of botanical families contain a large proportion of the dominant perennials in the area. Of these Acacia, Eremophila and Cassia are pre-eminent in the taller shrub communities, Atriplex and Maireana in the low chenopod shrublands, Eucalyptus in the low woodlands and Triodia and Plectrachne in the hummock grasslands

Single-machine scheduling with stepwise tardiness costs and release times

We study a scheduling problem that belongs to the yard operations component of the railroad planning problems, namely the hump sequencing problem. The scheduling problem is characterized as a single-machine problem with stepwise tardiness cost objectives. This is a new scheduling criterion which is also relevant in the context of traditional machine scheduling problems. We produce complexity results that characterize some cases of the problem as pseudo-polynomially solvable. For the difficult-to-solve cases of the problem, we develop mathematical programming formulations, and propose heuristic algorithms. We test the formulations and heuristic algorithms on randomly generated single-machine scheduling problems and real-life datasets for the hump sequencing problem. Our experiments show promising results for both sets of problems

Turbulence and angular momentum transport in a global accretion disk simulation

The global development of magnetohydrodynamic turbulence in an accretion disk is studied within a simplified disk model that omits vertical stratification. Starting with a weak vertical seed field, a saturated state is obtained after a few tens of orbits in which the energy in the predominantly toroidal magnetic field is still subthermal. The efficiency of angular momentum transport, parameterized by the Shakura-Sunyaev alpha parameter, is of the order of 0.1. The dominant contribution to alpha comes from magnetic stresses, which are enhanced by the presence of weak net vertical fields. The power spectra of the magnetic fields are flat or decline only slowly towards the largest scales accessible in the calculation, suggesting that the viscosity arising from MHD turbulence may not be a locally determined quantity. I discuss how these results compare with observationally inferred values of alpha, and possible implications for models of jet formation.Comment: ApJ Letters, in press. The paper and additional visualizations are available at http://www.cita.utoronto.ca/~armitage/global_abs.htm

Pause-and-Go Self-Balancing Formation Control of Autonomous Vehicles Using Vision and Ultrasound Sensors

In this work, we implement a decentralized and noncooperative state estimation and control algorithm to autonomously balance a team of robots in a circular formation pattern. The group of robots includes a leader periodically moving at a constant steering angle and a set of followers that, by only leveraging intermittent and noisy proximity measurements, independently implement a fully decentralized state estimation control algorithm to determine and adjust their relative position with closest neighbors. The algorithm is conducted in a pause-and-go sequence, where, during the pause, each robot stops to gather and process the information coming from the measurements, estimate the relative phase with respect to the others, and identify its closest pursuant. During the go, each robot accelerates to space from its closest pursuant and then to move at a constant speed when the desired spacing is achieved. The algorithm is tested in an unprecedented experiment on a custom-made low-cost caster-wheeled robotic framework featuring sonar and vision sensors mounted on a rotating platform to estimate the proximity distance to closer neighbors. The control scheme, which does not necessitate cooperation and is capable of coping with uncertain and intermittent sensor feedback data, is shown to be effective in balancing the robot on the circle even when, at a steady state, no feedback sensor data are available