1,952 research outputs found
Assessing Integrated Water Management Options for Urban Developments - Canberra case study
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
Bacterial Flora of Seven Species of Fish Collected at Rongelap and Eniwetok Atolls
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)
Visual Features Involving Motion Seen from Airport Control Towers
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
Static and Motion-Based Visual Features Used by Airport Tower Controllers: Some Implications for the Design of Remote or Virtual Towers
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
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
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
The interaction of lean and building information modeling in construction
Lean construction and Building Information Modeling are quite different initiatives, but both are having profound impacts on the construction industry. A rigorous analysis of the myriad specific interactions between them indicates that a synergy exists which, if properly understood in theoretical terms, can be exploited to improve construction processes beyond the degree to which it might be improved by application of either of these paradigms independently. Using a matrix that juxtaposes BIM functionalities with prescriptive lean construction principles, fifty-six interactions have been identified, all but four of which represent constructive interaction. Although evidence for the majority of these has been found, the matrix is not considered complete, but rather a framework for research to
explore the degree of validity of the interactions. Construction executives, managers, designers and developers of IT systems for construction can also benefit from the framework as an aid to recognizing the potential synergies when planning their lean and BIM adoption strategies
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GABA-modulating bacteria of the human gut microbiota.
The gut microbiota affects many important host functions, including the immune response and the nervous system1. However, while substantial progress has been made in growing diverse microorganisms of the microbiota2, 23-65% of species residing in the human gut remain uncultured3,4, which is an obstacle for understanding their biological roles. A likely reason for this unculturability is the absence in artificial media of key growth factors that are provided by neighbouring bacteria in situ5,6. In the present study, we used co-culture to isolate KLE1738, which required the presence of Bacteroides fragilis to grow. Bioassay-driven purification of B. fragilis supernatant led to the isolation of the growth factor, which, surprisingly, is the major inhibitory neurotransmitter GABA (γ-aminobutyric acid). GABA was the only tested nutrient that supported the growth of KLE1738, and a genome analysis supported a GABA-dependent metabolism mechanism. Using growth of KLE1738 as an indicator, we isolated a variety of GABA-producing bacteria, and found that Bacteroides ssp. produced large quantities of GABA. Genome-based metabolic modelling of the human gut microbiota revealed multiple genera with the predicted capability to produce or consume GABA. A transcriptome analysis of human stool samples from healthy individuals showed that GABA-producing pathways are actively expressed by Bacteroides, Parabacteroides and Escherichia species. By coupling 16S ribosmal RNA sequencing with functional magentic resonance imaging in patients with major depressive disorder, a disease associated with an altered GABA-mediated response, we found that the relative abundance levels of faecal Bacteroides are negatively correlated with brain signatures associated with depression
Self-Affirmation Improves Problem-Solving under Stress
High levels of acute and chronic stress are known to impair problem-solving and creativity on a broad range of tasks. Despite this evidence, we know little about protective factors for mitigating the deleterious effects of stress on problem-solving. Building on previous research showing that self-affirmation can buffer stress, we tested whether an experimental manipulation of self-affirmation improves problem-solving performance in chronically stressed participants. Eighty undergraduates indicated their perceived chronic stress over the previous month and were randomly assigned to either a self-affirmation or control condition. They then completed 30 difficult remote associate problem-solving items under time pressure in front of an evaluator. Results showed that self-affirmation improved problem-solving performance in underperforming chronically stressed individuals. This research suggests a novel means for boosting problem-solving under stress and may have important implications for understanding how self-affirmation boosts academic achievement in school settings. © 2013 Creswell et al
Is there evidence for export-led adoption of ISO 14001? A review of the literature using meta-regression
Does the export orientation of a firm affect the likelihood that it adopts an environmental management certification? We use meta-regression methods to analyze systematically the corpus of published research on export-led adoption of the largest and most prominent certification, ISO 14001. We show that the explanatory variables authors choose to include in their models reflect the tenets of stakeholder and institutional theories. We also find that the literature suffers from substantial publication bias but that, once this is accounted for appropriately, a genuine effect remains. The evidence from 20 years of published studies taken as a whole is that export does incentivize the adoption of the standard as often hypothesized by proponents of voluntary approaches and self-regulation
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