1,669 research outputs found

    Assessing Integrated Water Management Options for Urban Developments - Canberra case study

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    Urban water services in the Australian Capital Territory (ACT) are currently provided through conventional centralised systems, involving large scale water distribution, wastewater collection, water and wastewater treatment. A study was conducted to assist Environment ACT in setting broad policies for future water services in Canberra. This paper presents the outcomes of a study examining the effects of various water servicing options on water resources and the environment, for two townships in Canberra, one existing and one greenfield site. Three modelling tools were used to predict the effects of various alternative water servicing scenarios, including demand management options, rainwater tanks, greywater use, on-site detention tanks, gross pollutant traps, swales and ponds. The results show that potable water reductions are best achieved by demand management tools or a combination of greywater and rainwater use for existing suburbs, while 3rd pipe systems are preferred for greenfield sites. For this specific climatic region and end use demands, modelling predicted increased water savings from raintanks compared to greywater systems alone, with raintanks providing the additional benefit of reduced peak stormwater flows at the allotment scale. Rainwater and stormwater reuse from stormwater ponds within the catchments was found to provide the highest reduction in nutrient discharge from the case study areas. Environment ACT amended planning controls to facilitate installation of raintanks and greywater systems, and commenced a Government funded rebate scheme for raintanks as a result of this study

    Visual Features Involving Motion Seen from Airport Control Towers

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    Visual motion cues are used by tower controllers to support both visual and anticipated separation. Some of these cues are tabulated as part of the overall set of visual features used in towers to separate aircraft. An initial analyses of one motion cue, landing deceleration, is provided as a basis for evaluating how controllers detect and use it for spacing aircraft on or near the surface. Understanding cues like it will help determine if they can be safely used in a remote/virtual tower in which their presentation may be visually degraded

    Bacterial Flora of Seven Species of Fish Collected at Rongelap and Eniwetok Atolls

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    A very extensive literature exists concerning the normal bacterial flora of marine fish species common to the northern ocean areas, i.e., the North Sea (Stewart, 1932; Aschehoug and Vesterhus, 1943; Reay and Shewan, 1949; Liston, 1956, 1957; Georgala, 1958), the North Atlantic (Reed and Spence, 1929; Gibbons, 1934a, 1934b; Dyer, 1947), and the North Pacific (Hunter, 1920; Fellers, 1926; Snow and Beard, 1939; Kiser, 1944; Kiser and Beckwith, 1942, 1944; Liston, 1959). These studies of the aerobic heterotrophic bacterial flora found on a number of different species of northern ocean fishes have shown that, while the generic distribution of the bacteria associated with freshly caught marine fish may vary quantitatively, the following genera predominate fairly consisteritly: Pseudomonas, Achromobacter, Flavobacterium, and Micrococcus. The genera Proteus, Sarcina, Bacillus, Corynebacterium, and Serratia are encountered less often. Some investigators have discussed the biochemistry of the organisms isolated from marine fish (viz., Thjotte and Somme, 1943) but most of the physiology and biochemistry is limited to only a few properties studied for classifying the microorganisms. A somewhat more extensive discussion of the anabolic and catabolic aspects of the bacterial groups found on North Pacific fish has been given by Colwell (1961) and Liston and Colwell (1962)

    1960 Homecoming Program and 1916-1917 Class Reunion

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    This printed program was compiled for the Jacksonville State College Homecoming festivities in October 1960. As part of the activities, a class reunion was held October 7-8 for the State Normal School alumni from the 1916-1917 class and also the football teams of 1913-1918. Photographs of the alumni are included, along with a transcript of a speech given by R. Liston Crow, a S.N.S. alumnus who later served as treasurer at JSU. The speech details the lives and careers of many of the members of the Class of 1916-1917, along with school memories. The originals of the printed program and speech notes are held in the Crow Collection of Anniston-Calhoun County Public Library; ACCPL temporarily loaned the materials from which HCL created these digital surrogates.https://digitalcommons.jsu.edu/lib_ac_unihist_misc/1011/thumbnail.jp

    Static and Motion-Based Visual Features Used by Airport Tower Controllers: Some Implications for the Design of Remote or Virtual Towers

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    Visual motion and other visual cues are used by tower controllers to provide important support for their control tasks at and near airports. These cues are particularly important for anticipated separation. Some of them, which we call visual features, have been identified from structured interviews and discussions with 24 active air traffic controllers or supervisors. The visual information that these features provide has been analyzed with respect to possible ways it could be presented at a remote tower that does not allow a direct view of the airport. Two types of remote towers are possible. One could be based on a plan-view, map-like computer-generated display of the airport and its immediate surroundings. An alternative would present a composite perspective view of the airport and its surroundings, possibly provided by an array of radially mounted cameras positioned at the airport in lieu of a tower. An initial more detailed analyses of one of the specific landing cues identified by the controllers, landing deceleration, is provided as a basis for evaluating how controllers might detect and use it. Understanding other such cues will help identify the information that may be degraded or lost in a remote or virtual tower not located at the airport. Some initial suggestions how some of the lost visual information may be presented in displays are mentioned. Many of the cues considered involve visual motion, though some important static cues are also discussed

    Adaptive constraints for feature tracking

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    In this paper extensions to an existing tracking algorithm are described. These extensions implement adaptive tracking constraints in the form of regional upper-bound displacements and an adaptive track smoothness constraint. Together, these constraints make the tracking algorithm more flexible than the original algorithm (which used fixed tracking parameters) and provide greater confidence in the tracking results. The result of applying the new algorithm to high-resolution ECMWF reanalysis data is shown as an example of its effectiveness

    SCOLIOSIS: A REVIEW

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    School screening of adolescents reveals a high prevalence of mild rotational deformity. The objective of screening is to prevent serious deformity by regular review of these children, early recognition of progression and provision of spinal bracing for curves greater than 25°. Two per cent of students screened in the age range 11–13 years have curves greater than 10° but only two per thousand screened require active treatment. A programme of exercise combined with bracing until skeletal maturity is reached, obviates the need for major surgery. Indications for follow-up and treatment are reviewed, and some current concepts of the aetiology of idiopathic scoliosis are examined with particular emphasis on the relationship between scoliosis and growth

    Evolutionary pathways toward gigantism in sharks and rays

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    Through elasmobranch (sharks and rays) evolutionary history, gigantism evolved multiple times in phylogenetically distant species, some of which are now extinct. Interestingly, the world's largest elasmobranchs display two specializations found never to overlap: filter feeding and mesothermy. The contrasting lifestyles of elasmobranch giants provide an ideal case study to elucidate the evolutionary pathways leading to gigantism in the oceans. Here, we applied a phylogenetic approach to a global dataset of 459 taxa to study the evolution of elasmobranch gigantism. We found that filter feeders and mesotherms deviate from general relationships between trophic level and body size, and exhibit significantly larger sizes than ectothermic‐macropredators. We confirm that filter feeding arose multiple times during the Paleogene, and suggest the possibility of a single origin of mesothermy in the Cretaceous. Together, our results elucidate two main evolutionary pathways that enable gigantism: mesothermic and filter feeding. These pathways were followed by ancestrally large clades and facilitated extreme sizes through specializations for enhancing prey intake. Although a negligible percentage of ectothermic‐macropredators reach gigantic sizes, these species lack such specializations and are correspondingly constrained to the lower limits of gigantism. Importantly, the very adaptive strategies that enabled the evolution of the largest sharks can also confer high extinction susceptibility

    The tail of the Jurassic fish Leedsichthys problematicus (Osteichthyes: Actinopterygii) collected by Alfred Nicholson Leeds - an example of the importance of historical records in palaeontology

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    The specimen of the tail of <i>Leedsichthys problematicus</i>, now in The Natural History Museum, London, was one of the most spectacular fossil vertebrates from the Oxford Clay Formation of Peterborough, but as an isolated find it shares no bones in common with the holotype of the genus and species. However, a letter from Alfred Nicholson Leeds and related documents cast valuable new light on the excavation of the tail, indicating that it was discovered with cranial bones, gill-rakers, and two pectoral fins, thereby including elements that can potentially be compared with those of the holotype. The documents also clearly indicate that The Natural History Museum's specimen is not part of the same individual as any other numbered specimen of <i>Leedsichthys</i> as had been speculated on other occasions. The maximum size of the animal represented by The Natural History Museum's specimen was possibly around 9 metres, considerably less than previous estimates of up to 27.6 metres for <i>Leedsichthys</i>. Historical documentary evidence should therefore be rigorously checked both when studying historical specimens in science, and in preparing text for museum display labels
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