238 research outputs found
Initial Technology Review
This report presents a review of the technology for which the Author intends to develop a digital simulation. The technology being treated is the original Leslie rotary loudspeaker. The Leslie rotary loudspeaker is an analogue electromechanical system utilizing rotating sound sources to modify sound which is passed through it. Included in this report is a consideration of prior art in digital simulation of the Leslie rotary loudspeaker and recommendations for further development thereof. The intended digital simulation platform for further development is functional script for the Matlab R2011b environment.Architecture & Allied Art
Initial Technology Review
This report presents a review of the technology for which the Author intends to develop a digital simulation. The technology being treated is the original Leslie rotary loudspeaker. The Leslie rotary loudspeaker is an analogue electromechanical system utilizing rotating sound sources to modify sound which is passed through it. Included in this report is a consideration of prior art in digital simulation of the Leslie rotary loudspeaker and recommendations for further development thereof. The intended digital simulation platform for further development is functional script for the Matlab R2011b environment.Architecture & Allied Art
Relationships between faunal assemblages and habitat types in Broke Inlet, Western Australia
The work for this thesis was undertaken in Broke Inlet, a seasonally-open estuary on the south coast of Western Australia and the only estuary in that region which is regarded as ânear-pristineâ (Commonwealth of Australia, 2002). The only previous seasonal studies of the environmental and biotic characteristics of this estuary involved broad-based descriptions of the trends in salinity, temperature and ichthyofaunal characteristics at a limited number of sites. Furthermore, no attempt has been made to identify statistically the range of habitats present in the nearshore and offshore waters of this system, and the extents to which the characteristics of the fish and benthic invertebrate faunas are related to habitat type. These types of data provide not only reliable inventories of the habitat and faunal characteristics of Broke Inlet, but also a potential basis for predicting the likely impact of anthropogenic and climatic changes in Broke Inlet in the future.
The main aims of this thesis were as follows. (1) To use the method of Valesini et al. (2010), which employs enduring environmental characteristics, to identify quantitatively the range of habitats present throughout the nearshore and offshore waters of Broke Inlet. The enduring environmental characteristics represent three broad categories, i.e. the location of any site in terms of its proximity to marine and freshwater sources, the degree of exposure to wave activity and the type of substrate and/or submerged vegetation. (2) To test the hypothesis that the species richness, density, diversity and species compositions of the fish and benthic macroinvertebrate faunas differ among habitat types, seasons and, in the case of the fish fauna, also years. (3) To test the hypothesis that the pattern of relative differences among habitat types, as exhibited by their faunal compositions, is correlated with that defined by their (i) enduring environmental characteristics and (ii) non-enduring environmental characteristics (water physico-chemical variables and sediment characteristics).
A high resolution satellite image and a digital elevation model of Broke Inlet were used to measure the enduring environmental characteristics at 104 and 36 widely-distributed sites in nearshore and offshore waters, respectively. These data were used to construct separate Manhattan distance matrices for nearshore and offshore waters, which were then subjected to the CLUSTER and SIMPROF routines in PRIMER v6 to identify the various groups of sites that did not differ significantly in their environmental characteristics and which were thus considered to represent habitat types. Twelve and four distinct habitat types were identified in nearshore and offshore waters, respectively.
The ichthyofaunas at sites representing 11 nearshore (A-K) and three offshore (A-C) habitat types were sampled seasonally for two consecutive years using seine and gill nets, respectively. A total of 83,047 fish was collected from nearshore waters, representing 27 species from 19 families, with 99.6% of those fish belonging to six species which represent the Atherinidae (Atherinosoma elongata, Leptatherina wallacei and Leptatherina presbyteroides) or Gobiidae (Afurcagobius suppositus, Pseudogobius olorum and Favonigobius lateralis) and complete their life cycles within the estuary. Each of these species were found at each nearshore habitat type, except for P. olorum, which was not caught at habitat A.
The species richness, density and diversity of the nearshore fish fauna differed significantly among habitats, seasons and years, with habitat being the most influential factor. Generally, mean species richness and density were greatest at habitat types located in the entrance channel (B, G and H) and/or on the southern shore of the basin (C and G), while the fish assemblages were most depauperate at habitats near freshwater sources (A and J).
The nearshore ichthyofaunal composition of Broke Inlet differed significantly among habitats, seasons and years, with the first again being the most influential. However, the extents of the overall differences in composition during each sampling occasion were moderate. The lack of very pronounced ichthyofaunal differences among the various habitat types reflects the widespread distributions and high abundances of the above atherinid and gobiid species, and particularly of A. elongata and L. wallacei, which typified the fish fauna of each habitat type on almost all sampling occasions. The most distinctive of the faunas were those at habitat types in the entrance channel, where L. presbyteroides and F. lateralis, which are typically found in higher salinities, were in their greatest densities, and where several marine straggler species, such as the labrids Notolabrus parilus and Achoerodus gouldii, were occasionally caught. Seasonal and inter-annual changes in ichthyofaunal composition were small and often not consistent across habitats.
The pattern of relative differences among nearshore habitats in terms of their ichthyofaunal composition was correlated at a moderate level with that defined by their enduring environmental characteristics in all but one of the eight seasons. Such indicate that the ichthyofaunal composition likely to be found at any site in the nearshore waters of Broke Inlet at any time of year can be predicted, simply by assigning that site to its most appropriate habitat type on the basis of its enduring environmental characteristics. Differences in ichthyofaunal composition among habitat types were also correlated, but to a slightly greater extent, with those among the suite of non-enduring water physico-chemical variables, with salinity and the biomass of macrophytes being particularly relevant.
Gill netting in the three offshore habitats yielded 1,050 fish representing 31 species. Species richness, catch rates and diversity all varied significantly among habitats, with the values for each of these biotic characteristics always being greatest at habitat A in the entrance channel and lowest at habitat B near the Shannon River mouth. These biotic variables did not always vary, however, among seasons and/or years. In contrast to the situation in nearshore waters, the offshore ichthyofauna comprised mainly marine estuarine-opportunists and marine stragglers, which contributed 84% to the number of species and 80% to the total number of fishes. The contribution of individuals belonging to the marine straggler guild was only 5% and no estuarine resident species were caught.
Ichthyofaunal composition in offshore waters differed significantly among habitats, seasons and years, with habitat being the most influential factor. Faunal composition only differed among habitats in spring and autumn, and even then the extent of those differences was low. During those seasons, habitat B contained the most distinct and depauperate fauna, which was typified mainly by Mugil cephalus and Aldrichetta forsteri. In contrast, the fish assemblages at habitats A and C were also typified by Arripis georgianus, Arripis truttaceus, Rhabdosargus sarba, Pagrus auratus, Pseudocaranx dentex and Engraulis australis.
The pattern of relative differences among offshore sites in terms of their ichthyofaunal composition was significantly correlated with that defined by their enduring environmental characteristics only in autumn, but was moderately correlated with that exhibited by the suite of non-enduring water physico-chemical variables in each season except summer.
Seasonal sampling of benthic macroinvertebrates at six of the nearshore habitat types (A, C, D, F, H and K) for a year yielded 7,485 individuals representing 28 species and seven phyla and, at the three offshore habitat types (A-C), 2,459 individuals representing 26 species and eight phyla. Polychaetes (64 and 57%) and crustaceans (24 and 34%) were the most abundant taxa in nearshore and offshore waters, respectively. The mean density of invertebrates in the nearshore waters did not differ significantly among habitats, but did vary significantly among seasons, and was greatest in summer. The mean densities of invertebrates in offshore waters did not differ significantly, however, among habitats or seasons.
The compositions of nearshore benthic macroinvertebrate assemblages differed significantly among habitats and, less conspicuously, seasons. Comparisons between the faunal compositions in each pair of habitats in spring and summer were almost invariably significantly different and to a moderate extent. However, such pairwise comparisons were rarely significant in autumn and winter. Habitats A and K contained the most distinct and depauperate invertebrate fauna, comprising mainly the polychaete Capitella capitata and amphipod Corophium minor, whereas the other habitats also contained large numbers of the polychaete Ceratonereis aequisetis. In offshore waters, the composition of the benthic macroinvertebrate assemblages differed to a low to moderate degree among habitats, with habitat B containing the most distinct fauna due to large densities of C. minor. The extent of seasonal differences in these faunal compositions was small.
The pattern of relative differences among nearshore habitats in terms of their benthic macroinvertebrate composition was highly correlated with that defined by both their (i) enduring environmental characteristics and (ii) non-enduring water physico-chemical and sediment characteristics in spring and/or summer. Although the faunal and enduring environmental data were not correlated at offshore sites, the fauna and non-enduring environmental variables at those sites were correlated to a moderate extent.
In summary, the composition of the nearshore fish fauna at any site in Broke Inlet at any time of year can now be predicted by allocating that site to a particular habitat type on the basis of its enduring environmental characteristics. The less consistent spatial correlations between the compositions of the offshore fish fauna and benthic macroinvertebrate faunas and the enduring environmental variables largely reflected the ubiquitous nature of the majority of the abundant species representing those faunas, i.e. they are typically at least moderately abundant in all habitats and thus have no strong preferences for a particular habitat type
Alien Registration- Tweedley, Elizabeth (Portland, Cumberland County)
https://digitalmaine.com/alien_docs/23098/thumbnail.jp
A technique for expediting comprehensive written feedback on assignments
Providing detailed feedback in large classes is challenging. We describe how we develop an archive of comments while marking â noting good points, what needs improvement, and how to correct shortcomings. Comments are recorded in a single document with codes. Relevant codes are marked on studentsâ work where issues arise. Each studentâs annotated assignment is returned with a copy of the comments for the class. Thus, they receive specific feedback on their own work, plus all comments given to the class. Instructors save on marking time because comments are written once on the master list, and only codes and a personalized summary statement are written on the assignment. Markers may collaborate in preparing comments to assist in moderation; some generic comments (e.g., presentation and grammar) are portable across different assignments and years; and comments from past years may form a rubric for sharing with students before they start an assignment
Evaluating the effects of artificial oxygenation and hypoxia on biota in the Upper Swan Estuary: Final report
In 2010, the Swan River Trust commissioned Murdoch University to evaluate the effects of artificial oxygenation on the benthic macroinvertebrate (BMI) fauna of the Upper Swan Estuary (USE). The project involved the collection of BMIs monthly between January 2010 and December 2011, at five locations in the USE between Ron Courtney Island and just upstream of Middle Swan Bridge (i.e. the Jane Brook confluence). Specifically, the project had two components; 1) to describe any spatial and/or temporal patterns in the BMI community during eight consecutive seasons in 2010 and 2011 and 2) to assess the ecological and management implications of the findings, with specific reference to the effects of hypoxia (low dissolved oxygen) and of the artificial oxygenation program
Assessment of the condition of the Swan-Canning Estuary in 2015, based on the Fish Community Indices of estuarine condition. Final report to the Department of Parks and Wildlife
This report, commissioned by the Department of Parks and Wildlife, describes the monitoring and evaluation of fish communities in the Swan Canning Riverpark during 2015 and applies the Fish Community Indices (FCI) that have been developed in recent years as a measure of the ecological condition of the Swan Canning Estuary. These indices, developed for the shallow, nearshore waters of the estuary and also for its deeper, offshore waters, integrate information on various biological variables (metrics), each of which quantifies an aspect of the structure and/or function of estuarine fish communities and responds to a range of stressors affecting the ecosystem.
Fish communities were sampled using different nets at six nearshore and six offshore sites in each of four management zones of the estuary (Lower Swan Canning Estuary, LSCE; Canning Estuary, CE; Middle Swan Estuary, MSE; Upper Swan Estuary, USE) during summer and autumn of 2015. As many fish as possible were returned to the water alive after they had been identified and counted. The resulting data on the abundances of each fish species from each sample were used to calculate a Fish Community Index score (0-100). These index scores were then compared to established scoring thresholds to determine ecological condition grades (A-E) for each zone and for the estuary as a whole, based on the composition of the fish community
The Contrasting Ecology of Temperate Macrotidal and Microtidal Estuaries
Tidal range is a master factor governing the differences in physico-chemical and biological characteristics between microtidal (2 m) estuaries, which, for convenience, thus include mesotidal estuaries (2â4 m). Microtidal estuaries differ from macrotidal estuaries in geomorphology, tidal water movements, salinity regimes, residence times, turbidity, sedimentology and intertidal area. Consequently, their phytoplankton, microphytobenthos and macrophytes communities differ in biomass and production, areal extent, distribution patterns and composition. Mesozooplankton comprise predominantly autochthonous species in microtidal estuaries and allochthonous species in macrotidal estuaries. Meiobenthos in microtidal estuaries have greater densities in subtidal than intertidal areas and species persist along the estuary. Macrobenthos is dominated by small deposit-feeding species in microtidal estuaries, whereas macrotidal estuaries contain some larger species and suspension feeders. Species richness and abundance of estuarine-resident fish species and the contributions of diving piscivorous birds and wading invertebrate-feeding birds are greater in microtidal estuaries. As paradigms regarding estuarine ecology have been based mainly on northern hemisphere macrotidal systems, this review has redressed this imbalance by detailing the extent of differences between microtidal and macrotidal estuaries. In particular, it uses data and case studies for southern hemisphere microtidal systems to demonstrate that the physico-chemical characteristics and ecology of the main flora and fauna of microtidal estuaries are frequently not consistent with those paradigms
Can biotic indicators distinguish between natural and anthropogenic environmental stress in estuaries?
Because estuaries are naturally stressed, due to variations in salinity, organic loadings, sediment stability and oxygen concentrations over both spatial and temporal scales, it is difficult both to set baseline reference conditions and to distinguish between natural and anthropogenic environmental stresses. This contrasts with the situation in marine coastal and offshore locations. A very large benthic macroinvertebrate dataset and matching concentrations for seven toxic heavy metals (i.e. Cr, Ni, Cu, Zn, Cd, Hg and Pb), compiled over three years as part of the UK's National Marine Monitoring Programme (NMMP) for 27 subtidal sites in 16 estuaries and 34 coastal marine sites in the United Kingdom, have been analysed. The results demonstrate that species composition and most benthic biotic indicators (number of taxa, overall density, ShannonâWiener diversity, Simpson's index and AZTI's Marine Biotic Index [AMBI]) for sites in estuarine and coastal areas were significantly different, reflecting natural differences between these two environments. ShannonâWiener diversity and AMBI were not significantly correlated either with overall heavy metal contaminant loadings or with individual heavy metal concentrations (ânormalizedâ as heavy metal/aluminium ratios) in estuaries. In contrast, average taxonomic distinctness (Î+) and variation in taxonomic distinctness (Î+) did not differ significantly between estuarine and coastal environments, i.e. they were unaffected by natural differences between these two environments, but both were significantly correlated with overall heavy metal concentrations. Furthermore, Î+ was correlated significantly with the Cu, Zn, Cd, Hg and Pb concentrations and Î+ was correlated significantly with the Cr, Ni, Cu, Cd and Hg concentrations. Thus, one or both of these two taxonomic distinctness indices are significantly correlated with the concentrations for each of these seven heavy metals. These taxonomic distinctness indices are therefore considered appropriate indicators of anthropogenic disturbance in estuaries, as they allow a regional reference condition to be set from which significant departures can then be determined
Monitoring the recruitment success of Black Bream in the Vasse-Wonnerup two years after a large fish kill
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