Australian waterbirds : time and space travellers in dynamic desert landscapes

Australia’s waterbirds are mostly nomadic, capitalising on highly variable aquatic resources in the arid interior (70% of the continent) for feeding and breeding. Waterbirds, unlike most aquatic organisms, can move between catchments, exploiting habitat wherever it occurs. In Australia, patterns of resource availability for waterbirds are mostly pulsed with peaks of productivity, coinciding with flooding and differing in time and space, affecting individuals, species and functional groups of waterbirds. Australian waterbirds are no different from waterbirds elsewhere, with their behaviour reflecting broad-scale resource availability. They respond to changing patterns of resource distribution, with rapid movements at spatial and temporal scales commensurate with the dynamics of the resource. The most serious conservation threat to waterbirds is a bottleneck in resource availability, leading to population declines, increasingly forced by anthropogenic impacts. River regulation and other threats (e.g. draining) reduce the availability of wetland habitat and decrease the probability of viable resource patches. It is axiomatic that waterbirds need water and such population bottlenecks may occur when the availability of water across the continent is limited. The rehabilitation of regulated rivers with environmental flows and protection of naturally flowing rivers in the arid region are essential for long-term sustainability of Australia’s waterbird populations.

Globalizing time and space : temporal and spatial considerations in discourses of globalization

Globalization discourse is concerned with the effects of spatial change—changes in the shape, scale and extensity or social processes— and the effects of temporal change—particularly changes to, or away from, modernity. By drawing together both axes of change, globalization discourse suggests a way of navigating this tension. However, it is argued here that most globalization theories accord primacy to one of these axes, which results in them being conflated. As a result, globalization theories are often presented in highly systemic terms and downplay the diversity of social processes.

History's motion : on absolute time and space in Tibet

On-going contestations to establish the hegemonic narrative of Tibet's history rest on the shared assumption that a true narrative, or history's motion, exists. This essay suggests that history's motion is a continuing legacy of Newton's concepts of absolute time and space, even while the current disputes over Tibet's history point to the limitations of these concepts in practice.

Time and spatial resolution of slip and twinning in a grain embedded within a magnesium polycrystal

Plastic yielding in magnesium alloys frequently involves the initiation of both slip and twinning events. A proper understanding of the phenomenon at the grain level requires knowledge of how these two mechanisms progress and interact over both time and space and what the local resolved stresses are. To date, simultaneous collection of such information has not been achievable. To address this shortfall, we have developed a modified Laue based in situ micro X-ray diffraction technique with an unprecedented combination of time and spatial resolution. A ten-fold reduction in data collection times is realized by the refinement of rapid polychromatic Laue "single-shot" mapping. From single Laue patterns, we extract grain depth information, detect onset of yielding and achieve 2 × 10-4 lattice strain resolution. The technique is employed to examine yielding and twinning in a magnesium grain embedded ∼200 μm below the sample surface. We examine 13 time steps and reveal the following behaviour: initial onset of basal slip, subsequent onset of twinning, development of further accommodation slip and evolution of twin shape and size; along with the corresponding values of local resolved shear stresses. © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Avoiding competition? Site use, diet and foraging behaviours in two similarly sized geese wintering in China

Competition may occur when two species with similar feeding ecologies exploit the same limited resources in time and space. In recent years, the Eastern Tundra Bean Goose Anser fabalis serrirostris and Greater White-fronted Goose Anser albifrons frontalis have increased in wintering numbers at Shengjin Lake, China. To examine the potential for coexistence and possible avoidance strategies, we studied (1) their habitat use, (2) foraging behaviours and (3) diets of birds foraging in mixed- and single-species flocks. Both species extensively exploited sedge meadows, where they showed considerable overlap in spatial distribution and diet. The percentage feeding time and diet of both species were unaffected by the presence of the other. Greater White-fronted Geese appeared diurnal sedge meadow specialists, almost never feeding in other habitats. Eastern Tundra Bean Geese were less selective, exploiting other habitats, which they increasingly exploited at night in mid-winter. The use of alternative habitats and night feeding may have avoided interspecific competition. While the specialised feeding ecology of Greater White-fronted Geese may make them particularly vulnerable to loss of sedge meadow habitat, Eastern Tundra Bean Geese may be able to adjust because of their use of alternative habitats and a less restricted diet.

Use of geographical information systems as a tool for predicting fish yield in tropical reservoirs : case study on Sri Lankan reservoirs

Use of geographical information systems (GIS) in inland fisheries has hitherto been essentially restricted to site evaluation for aquaculture development and assessment of limnological changes in time and space in individual water bodies. The present GIS study was conducted on the land-use pattern of the catchments of nine reservoirs in Sri Lanka, for which detailed fishery data, viz. yield, fishing intensity, landing size of major constituent species, together with selected limnological data such as conductivity and chlorophyll-a, were available. Potential statistical relationships (linear, curvilinear, exponential and second-order polynomial) of fish yield (FY, in kg ha−1 yr−1) to different land-use patterns, such as forest cover (FC, in km2) and shrub-land (SL, in km2), either singly, or in combination, and/or the ratio of each land type to reservoir area (RA in km2) and reservoir capacity (RC in km3), were explored. Highly significant relationships were evident between FY to the ratio of SL and/or FC+SL to RA and/or RC. Similarly, the above land-use types to RA and RC ratios were significantly related to limnological features of the reservoirs. The relationships of FY to various parameters obtained in this study were much better correlated than those relationships of FY to limnological and biological parameters used in yield prediction in tropical and temperate lacustrine waters previously.

Exechonella (Exechonellidae: Bryozoa, Cheilostomata) from the recent and miocene of Southern Australia

The cheilostome family Exechonellidae Harmer, 1957 is widely distributed in time and space. The genus Exechonella Duvergier, 1924 has a pan-tropical to subtropical distribution from the Eocene to the Recent and is represented by several Australian species from the Tertiary of Victoria and the Recent ofthe southern and eastern coasts. Some species exhibit a wide range of variation in morphological characters, and one, Exechonella papillata, "appears to be new, and is described here. Nearly all specimens are encrusting, but one Tertiary Victorian species has erect, cylindrical, branching colonies. Recent samples, from a depth range of 40-190 metres, include large colonies of several thousand zooids. Frontal wall structures include marginal septular pores connecting between the visceral and hypostegal coeloms, and frontal foramina. Avicularia and homologous structures derived from frontal septular pores are illustrated. The structure of the frontal foramina in different populations of Tertiary E. marginata, demonstrates a major development of hypostegal coelom not found in other species, but resembling that found in another exechonellid genus, Stephanopora Kirkpatrick, 1888.

On animal distributions in dynamic landscapes

Few landscapes are static and patterns of resource distribution can vary markedly in time and space. Patterns of movement and dispersal in response to environmental change are equally diverse and occur on a broad range of temporal scales. For patterns of movement and dispersal that vary spatially and temporally throughout the life-time of an individual, the concepts of home range and geographic range alone do not adequately describe the observed patterns of distribution of individuals, populations or species. Here we further simplify Gauthreaux (1982) classification of movement types into a simple bipartite system and link movements (or lack thereof) to a similarly simple classification of ranges. In addition, we introduce two new indices that describe the relationship of an individual's life-time movements to its distribution as described by home and geographic range. Our interest in this subject arose from endeavouring to interpret local changes in waterbird abundance in the arid interior of the Australian continent and to understand these changes in relation to patterns of resource distribution and movement. In this discussion we focus on terrestrial vertebrates capable of multiple breeding events throughout an extended life-time.

How to diagnose multiple sclerosis and what are the pitfalls

The task of confirming a diagnosis of multiple sclerosis (MS), one of the commonest neurological disorders affecting young adults, has altered significantly in the magnetic resonance imaging era. Conversely, key principles, most notably objective documentation of neurological dissemination in time and space, remain fundamental to the process. Clinical acumen and experience are equally as crucial as an ability to interpret relevant investigations. Recognising typical clinical patterns, addressing potential 'mimics', and stratifying prognosis of a clinically isolated syndrome are just some of the challenges inherent in diagnosing MS.

Floodplain wetlands of the Gellibrand estuary: What type of invertebrate community

Introduction. Along the south coast of Australia, wetlands on the floodplains of lowland rivers and estuaries have been severely altered by agriculture and urbanization. Efforts to restore or rehabilitate these wetlands are hampered by insufficient knowledge of the original condition of these wetlands, or their variability in time and space. This research describes the macroinvertebrate community of wetlands on the floodplain of the Gellibrand River and estuary, which has suffered comparatively few human impacts. The aim of the research was to describe the variability of macroinvertebrate communities as a baseline for the future management of these wetlands, and to contribute to the general understanding of estuary-floodplain wetlands, thereby improving the basis for their management.

The Gellibrand River has a catchment area of approximately 1200 km2 draining the western slopes of the Otway Ranges, and entering the Southern Ocean at Princetown. From a mean annual flow of 315 000 mL, 25 000 mL are removed per annum for agricultural and domestic use (O'May & Wallace 2001), and flows are closer to natural regimes than most other Western Victorian rivers. The estuary is a bar-built, salt-wedge estuary that becomes completely blocked by the sand bar in most years, during summer and autumn. Over past decades, the estuary mouth has been opened artificially in most years. to prevent flooding of agricultural land and roads adjacent to the wetlands. At its maximum, the salt-wedge penetrates approximately 10 km upstream from the river mouth, but the estuary may also be completely fresh during high winter discharge
(Mckay 2000).

The wetlands surrounding Princetown cover 119 ha and are listed as nationally important (Environment Australia 2001). This listing regards the wetlands as an important habitat for animals at vulnerable stages of their life cycle and a refuge from adverse conditions, such as drought. They are a good example of coastal brackish and freshwater marshes, with an important ecological and hydrological role as part of a large wetland
complex.

The influence of polymerization time and dopant concentration on the absorption of microwave radiation in conducting polypyrrole coated textiles

Temperature changes in conducting polypyrrole/para-toluene-2-sulphonic acid (PPy/pTSA) coated nylon textiles due to microwave absorption in the 8–9 GHz and 15–16 GHz frequency ranges were obtained by a thermography station during simultaneous irradiation of the samples. The temperature values are compared and related to the amounts of reflection, transmission and absorption obtained with a non-contact free space transmission technique, indicating a relationship between microwave absorption and temperature increase. Non-conductive samples showed no temperature increase upon irradiation irrespective of frequency range. The maximum temperature difference of around 4 °C in the conducting fabrics relative to ambient temperature was observed in samples having 48% absorption and 26.5 ± 4% reflection. Samples polymerized for 60 or 120 min with a dopant concentration of 0.018 mol/l or polymerized for 180 min with a dopant concentration of 0.009 mol/l yielded optimum absorption levels. As the surface resistivity decreased and the reflection levels increased, the temperature increase upon irradiation reduced.

Conventions of pictorialism (iconic imagery, perceived space and the picture plane) deconstructed and reconstructed as alternative models of perception, embodied in paintings and drawings

This thesis is concerned with conventions of pictorialism, viz. the surface of an artwork or the plane of denotation (in my case paper, canvas or wood); and iconic imagery and the depiction of perceptual space that is connotated by marks, colours and forms upon that surface. Most importantly this thesis is concerned with the relationship between these elements and the deconstruction of them. That the reconstruction of the deconstructed language can create expressive iconic structures that perhaps contain conflicting information and elements, but are simultaneously single and self-contained perceptual models of seeing the world, and the things in it, in another way; is a major focus. The thesis is embodied in the paintings and drawings which are documented in the exegesis that follows.