1,412 research outputs found

    Distribution of freshwater fish in the south-western corner of Australia

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    This study investigates the distribution of freshwater fishes in the Busselton to Walpole Region. A total of 311 sites in 19 major catchments along the south-west coast from Capel to Walpole, were sampled using a variety of methods. New data was collated with that from previous studies to generate 15 species distribution maps. Habitat and life history notes and recommendations for conservation are made for each species. Changes in fish distribution are also commented upon. This study contributes to series of documents published for the purposes of water allocation planning in the Busselton to Walpole Region

    Distribution, identification and biology of freshwater fishes in south-western Australia

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    A total of 410 sites in the major watersheds in the south-western corner of Australia, bounded by Bunbury in the north-west and just east of Albany in the south-east, were sampled for fish. Sampling of the different sites was carried out using one or more of the following methods, namely seine netting, scoop netting, trapping and electrofishing to catch juvenile and adult fish, and light trapping, scoop netting and haul netting to collect larval fish. The fish caught at each site were identified and the number of each species recorded. These data were then collated, both with those derived from the studies of Christensen (1982) and Jaensch (1992) and with the records of the Western Australian Museum (WAM), to elucidate the distributions of each of the fish species found in freshwater in south-western Australia. The eight species endemic to south-western Australia are Tandanus bostocki, Lepidogalaxias salamandroides, Galaxias occidentalis, Galaxiella nigrostriata, Galaxiella munda, Bostockia porosa, Edelia vittata and Nannatherina baIstoni. The other species found in this region include Galaxias truttaceus and Galaxias maculatus, which are also represented in south-eastern mainland Australia and Tasmania, the anadromous lamprey Geotria australis, and those teleosts which are commonly found in freshwater, but belong to predominantly marine families, i.e. Leptatherina wallacei, Pseudogobius olonum and Afurcagobius suppositus. Finally, there are those species that have been introduced into the region, i.e. Oncorhynchus mykiss, Salmo trutta, Gambusia holbrooki and Perca fluviatilis

    Goldfish control in the Vasse River: summary of the 2008 programme

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    This report summarises the results of the 2008 round of the feral Goldfish control in the lower Vasse River and comparisons made with previous control efforts since 2004

    Ascending the Avon: fishes of the Northam Pool, and the Swan-Avon catchment

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    The fish fauna in the vicinity of the Northam Pool Weir was sampled seasonally between winter 2008 and autumn 2009. The results indicate that the fish community was characterised by species that are halotolerant including two estuarine species, the Western Hardyhead and Swan River Goby that are likely to have undergone large upstream expansions in the Swan‐Avon catchment due to secondary salinisation. However, two freshwater endemic species, the Western Minnow and Nightfish were also recorded in the vicinity of the weir. These, and other freshwater endemic species, have undergone large range reductions in this catchment as a result of salinisation. The study found evidence that the weir may be impeding the upstream movements of native fishes as found elsewhere in south‐western Australia and that construction of a well‐designed fishway would enhance population connectivity and increase their sustainability. It is recommended that additional sampling occurs during the major spawning periods of the freshwater species immediately below the weir to determine precisely when a future fishway would need to operate to allow maximum usage by resident native species. It is also recommended that fresh refuge habitats for freshwater fishes be identified to allow effective management measures to be implemented in those systems to halt their decline and reduce the risk of complete loss of these species from the Swan‐Avon catchment

    Distribution of the spotted minnow (Galaxias maculatus (Jenyns, 1842)) (Teleostei: Galaxiidae) in Western Australia including range extensions and sympatric species

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    Galaxias maculatus was captured from a number of rivers outside its previously known range. In Western Australia, it was formerly only known from rivers and lakes between the Goodga River (Two People's Bay, 30 km east of Albany) and the Dailey River (50 km east of Esperance), with additional records from the Boat Harbour Lakes (Kent River). An intensive survey of the inland fishes in rivers and lakes along the south coast of Western Australia has extended its distribution east by 50 km (Thomas River), west by approximately 40 km (Walpole River) and north by 400 km (Harvey River). The Western Australian Museum also has a specimen from the Canning River, a further 100 km north. Field salinity tolerance of G maculatus was high, with fish found alive in 81 mScm 1 (-45 ppt). The freshwater piscifauna east of, and including, the Pallinup River is depauperate, with G. maculatusbeing the only freshwater species present. All sympatric teleosts are tolerant of salinity and, with the exception of the introduced Gambusia holbrooki, are estuarine, including Pseudogobius olorum, Leptatherina wallacei and Acanthopagrus butcheri

    Security Issues in OAuth 2.0 SSO Implementations

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    Abstract. Many Chinese websites (relying parties) use OAuth 2.0 as the basis of a single sign-on service to ease password management for users. Many sites support five or more different OAuth 2.0 identity providers, giving users choice in their trust point. However, although OAuth 2.0 has been widely implemented (particularly in China), little attention has been paid to security in practice. In this paper we report on a detailed study of OAuth 2.0 implementation security for ten major identity providers and 60 relying parties, all based in China. This study reveals two critical vulnerabilities present in many implementations, both allowing an attacker to control a victim user’s accounts at a relying party without knowing the user’s account name or password. We provide sim-ple, practical recommendations for identity providers and relying parties to enable them to mitigate these vulnerabilities. The vulnerabilities have been reported to the parties concerned.

    A Comment on "The Far Future of Exoplanet Direct Characterization" - the Case for Interstellar Space Probes

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    Following on from ideas presented in a recent paper by Schneider et al. (2010) on "The Far Future of Exoplanet Direct Characterization", I argue that they have exaggerated the technical obstacles to performing such 'direct characterization' by means of fast (order 0.1c) interstellar space probes. A brief summary of rapid interstellar spaceflight concepts that may be found in the literature is presented. I argue that the presence of interstellar dust grains, while certainly something which will need to be allowed for in interstellar vehicle design, is unlikely to be the kind of 'show stopper' suggested by Schneider et al. Astrobiology as a discipline would be a major beneficiary of developing an interstellar spaceflight capability, albeit in the longer term, and I argue that astrobiologists should keep an open mind to the possibilities.Comment: Accepted for publication in Astrobiolog

    The Muonium Atom as a Probe of Physics beyond the Standard Model

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    The observed interactions between particles are not fully explained in the successful theoretical description of the standard model to date. Due to the close confinement of the bound state muonium (M=μ+eM = \mu^+ e^-) can be used as an ideal probe of quantum electrodynamics and weak interaction and also for a search for additional interactions between leptons. Of special interest is the lepton number violating process of sponteanous conversion of muonium to antimuonium.Comment: 15 pages,6 figure

    Electronic transport in films of colloidal CdSe nanocrystals

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    We present results for electronic transport measurements on large three-dimensional arrays of CdSe nanocrystals. In response to a step in the applied voltage, we observe a power-law decay of the current over five orders of magnitude in time. Furthermore, we observe no steady-state dark current for fields up to 10^6 V/cm and times as long as 2x10^4 seconds. Although the power-law form of the decay is quite general, there are quantitative variations with temperature, applied field, sample history, and the material parameters of the array. Despite evidence that the charge injected into the film during the measurement causes the decay of current, we find field-scaling of the current at all times. The observation of extremely long-lived current transients suggests the importance of long-range Coulomb interactions between charges on different nanocrystals.Comment: 11 pages, 10 figure

    Nannoperca pygmaea

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    Little Pygmy Perch Nannoperca pygmaea has most recently been assessed for The IUCN Red List of Threatened Species in 2019. Nannoperca pygmaea is listed as Endangered under criteria B1ab(i,ii,iii,v)+2ab(i,ii,iii,v)
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