2,634 research outputs found
Endangered sawfishes and river sharks in Western Australia
The coastal waters of the northern Pilbara and the western Kimberley are a global hotspot for sawfish (Pristidae) diversity, with four of the world’s seven1 species found there; these four species comprise all of the known Australian species. This unique group of rays is readily identified by the presence of a blade like snout possessing enlarged tooth like denticles known as rostral teeth (Last and Stevens 2009). Globally, almost all sawfishes have undergone major declines in both range and abundance, largely as a result of their vulnerability to entanglement in fishing nets, but also through loss of habitat. It is only recently that information on the distribution, ecology, biology, population demographics and genetics and habitat utilization of the Australian sawfish fauna has started to become available, with much of this information restricted to grey literature or as unpublished work in progress. There is limited (or no) information on the size of the remaining populations, but many of the world’s sawfish populations are thought to survive in small fragmented areas (e.g. Simpfendorfer 2000). The four Australian species are from two genera, and are typically found throughout northern Australia, but accurate distributional descriptions are hindered by a lack of targeted surveying and are based on: limited surveys, from anecdotal reports or from collections of dried rostra. However, the Pilbara coast and west Kimberley are known to represent an important area for the four species, namely Freshwater Sawfish (Pristis microdon), Dwarf Sawfish (Pristis clavata), Green Sawfish (Pristis zijsron) and the Narrow Sawfish (Anoxypristis cuspidata).The first three of these species are listed as vulnerable under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and these form the basis of this review; although all are protected species within Western Australia under the Fish Resource Management Act 1994 (FRMA Act). Pristis zijsron was also listed under Schedule 1 of the Wildlife Conservation Act 1950 in Western Australia in 2006.Woodside Energy Ltd contracted the Centre for Fish & Fisheries Research (Murdoch University) to provide an overview of the current knowledge of the three EPBC Act listed pristids (P. microdon, P. clavata and P. zijsron) and also the Endangered (EPBC Act) Northern River Shark (Glyphis garricki) in Western Australian waters.Glyphis garricki was discovered in Western Australia in 2002 (Thorburn and Morgan 2004) and its formal description is recent (Compagno et al. 2008).Collectively, these species represent 50% of Australia’s elasmobranchs that are listed as Vulnerable or higher under the EPBC Act
This report presents all known information with regard to their distribution in Western Australia, morphological characteristics, habitat utilization and population structure and genetic diversity in relation to northern Australia populations. The relevance of these data are then discussed in relation to the James Price Point development
Redundancy Strategies for a High Splitting Optically Amplified Passive Optical Network
Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.High splitting, optically amplified, passive optical networks (SuperPONs) are investigated in terms of redundancy provision and protection mechanisms. Options for redundancy, including the important special case of dual homing, are detailed, and it is determined as to which of these options (duplication of the feeder and first distribution section, and N+1 protection of the optical amplifiers in the amplified splitter) would be required to be provided to all attached users to facilitate appropriate availability of the basic telephony service. The distributed amplified splitter dual homing solution is found to outperform the single amplified splitter solution in terms of its survivability. The protection mechanisms necessary to automatically switch to the redundant provision are discussed and it is seen that with the aid of suitable regular precautionary procedures protection switching can generally be provided rapidly (<50 ms). Finally, an availability, and cost versus availability, study confirms the aforementioned redundancy assessment for fiber-to-the-home (FTTH) implementations, but shows fiber-to-the-curb (FTTC) as needing additional redundancyPeer reviewe
Macrostructural analysis : unravelling polyphase glacitectonic histories
Many Pleistocene glacial profiles look extremely simple, comprising till, or glacitectonite, overlying
older sediments or bedrock (Figure 4.1). In more complex sequences the till may itself be overlain by
younger sediments laid down as the ice retreated or during a completely separate, later phase of
advance. Macroscopically, subglacial traction tills (Evans et al., 2007) are typically massive,
unstructured deposits suggesting that it should be relatively straightforward to unravel the
glacitectonic deformation history recorded by the sequence. Many reconstructions do indeed look
very simple, slabs of sediment have been tilted and stacked and then overridden by the glacier to
cap the structure with till. Added to this is the use of vertical exaggeration which makes the whole
structure look like alpine tectonics (for an example see fig. 5 in van Gijssel, 1987). Dropping the
exaggeration led to the recognition that actually we were looking at much more horizontal
structures, i.e. overriding nappes and not imbricated slabs (van der Wateren, 1987).
Traditionally (van der Meer, 1987) glaciotectonics was thought to relate to large structures
like big push moraines and not to smaller structures like drag structures underneath tills (Figure 4.2),
let alone to the tills themselves. With the notion that deforming bed tills are tectonically and not
sedimentologically structured and could be regarded as tectomicts (Menzies et al., 2006), comes the
realisation that glacitectonics happens across a wide range of scales, from the microscopic to tens of
kilometres. Only by realising the full range of glaciotectonic scales can we hope to understand the
processes
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The Sensing Endotracheal Tube
Current pulse oximetry sensors are not very wellsuited to use in anaesthetised patients as it has been shownthat during episodes of reduced peripheral circulation they donot function correctly or fail all together [1], [2]. To addressthis problem a new design for a photoplethysmography (PPG)endotracheal (ET) sensor to monitor pulse rate and oxygensaturation (SpO2) internally is presented. Flexible printedcircuit board (PCB) technology and miniature optoelectroniccomponents have been implemented and integrated with acustom instrumentation system [3]. The sensor adheres andconforms to the curvature of standard french-gauge 7 and 8ET tubes at the point just above the inflatable cuff within thelaryngeal positioning markings. A 3D-modelled, optically clear,soft silicon encapsulation electronically and thermally isolatesthe electronic components whilst providing a smooth surface toaid the insertion on the ET tube during standard intubationprocedures. A pilot study with 5 patients (3 Female, 2 Male),undergoing abdominal and limb laproscopic procedures hasdemonstrated the operation of the sensing ET tube, showinggood quality red and infra-red PPG signals. Preliminary signalanalysis reveals heart rate can be measured via PPG success-fully, with saturation (SpO2) readings in close agreement withthe commercial monitors of 97.9% (STD 0.2%) and 98.6% (STD 0.8%) respectivel
Attempts to transmit hepatitis B virus to chimpanzees by arthropods
Bedbugs (Cimex lectularius L.) were fed on an infective blood-hepatitis B virus (HBV) mixture. Further bedbugs and tampan ticks (Ornithodoros moubata [MurrayJ) were fed on HBV-carrier chimpanzees. After a 10 - 13 day interval for oviposition, tests done on samples of individual arthropods showed that 53 - 85% of the bugs were HBsAg-positive and none HBeAg-positive, while 100% of the ticks were HBsAgpositive and 88% HBeAg-positive. The remaining arthropods were fed on 3 susceptible chimpanzees, which had failed to develop HBV infection after 11 months, indicating no transmission had occurred. Subsequently the presence of viable virus in the original infective meals was confirmed by inoculation of the relevant donor sera directly into the 3 still susceptible chimpanzees. HBV infections quickly followed in each animal. It is concluded that, while mechanical transmission of HBV is most unlikely after a 10 - 13-day interval between feedings in bedbugs and tampans, it is still possible that mechanical transmission between humans might occur during interrupted feeds
Marine benthic flora and fauna of Gourdon Bay and the Dampier Peninsula in the Kimberley region of North-Western Australia
Surveys undertaken to characterise the marine benthic habitats along the Dampier Peninsula and further south at Gourdon Bay in the Kimberley region of Western Australia were augmented with epibenthic sled sampling of soft and hard bottom habitats. This paper describes the species collected, their biomass and relative abundance for the main groups of marine macrophytes and invertebrates. Five localities were surveyed; Gourdon Bay, Quondong Point to Coulomb Point, Carnot Bay to Beagle Bay, Perpendicular Head and Packer Island. Sampling was limited to fifteen epibenthic dredge operations from a range of habitat types and was designed to target the most common habitat types and to obtain species identifications of the most important species and those which typified different habitat types. Surveys covered a total of 1,350 m 2 of seabed in depths between 11 and 23m. We identified 415 taxa comprising: 1 seagrass, 43 algae, 52 sponges, 30 ascidians, 10 hydroids, 14 scleractinian corals, 52 other cnidarians, 69 crustaceans, 73 molluscs and 71 echinoderms. Despite the limited nature of the sampling, a significant number of new species, range extensions and new records for Western Australia and Australia were recorded. Within the algae, one range extension (Halimeda cf. cuneata f. digitata not previously recorded in Western Australia) and one possible new species of Areschougia were recorded. Two range extensions were present in the ascidians; the solitary ascidian Polycarpa cf. intonata has previously only been recorded in Queensland and Cnemidocarpa cf. radicosa only in temperate Australian waters. There were several range extensions for the crustacea, for example, the sponge crab, Tumidodromia dormia, has only been recorded in Queensland. One species of holothurian of the genus Phyllophorus could not be identified from the literature available and may represent a new species. Similarly, a small species of the echinoid Gymnechinus could possibly be a new species. The collections of hydroids, hard corals, crinoids and molluscs contained no new species or range extensions. There was difficulty in identification of some groups to species level due to the status of the current taxonomic literature (e.g. Cnidaria, Porifera and ascidians) and there may be a number of new species among the material collected. Among the anthozoa, there is at least one new species of Chromonephthea and potentially 10 range extensions to Western Australia. Sinularia cf. acuta and Chromonephthea curvata are both new records for Australia with both previously recorded in Indonesia only. Among the better known taxa (e.g. molluscs, echinoderms, corals), most of the taxa identified to species level have been recorded to occur throughout north-western Australia, however the diversity recorded in this study is less than other parts of the Kimberley and this is almost certainly a result of the small overall area sampled and the single method of collection utilised. The most important species on soft bottom habitats in terms of biomass was the heart urchin Breynia desorii (up to 326 g.m -2). Sponges were the dominant fauna by biomass (up to 620 g.m -2) on hard bottom habitats and biomass was dominated a by a few large cup and massive sponge species (e.g. Pione velans and two unidentified Spheciospongia). The biomass of other filter feeders, especially ascidians (e.g. Aplidium cf. crateriferum), soft corals (e.g. Chromonephthea spp.), gorgonians (e.g. Junceella fragilis and Dichotella gemmacea) was also high, indicating the importance of these groups in characterising hard bottom habitats. Although low in biomass, crinoids such as Comaster multifidus and Comatula pectinata were abundant in samples that included a high biomass of other filter feeders
Towards a novel carbon device for the treatment of sepsis
Sepsis is a systemic inflammatory response to infection in which the balance of pro- andanti-inflammatory mediators, which normally isolate and eliminate infection, is disrupted[1]. Gram negative sepsis is initiated by bacterial endotoxin release which activatesmacrophages and circulating monocytes to release TNF and IL-1β followed by IL-6 andother inflammatory cytokines [2]. As the disease progresses, an unregulatedinflammatory response results in, tissue injury, haematological dysfunction and organdysfunction. Severe sepsis, involving organ hypoperfusion may be further complicatedby hypotension that is unresponsive to adequate fluid replacement, resulting in septicshock and finally death [3].Despite improvements in anti-microbial and supportive therapies, sepsis remains asignificant cause of morbidity and mortality in ICUs worldwide [4]. The complexity ofprocesses mediating the progression of sepsis suggests that an extracorporeal devicecombining blood filtration with adsorption of a wide range of toxins, and inflammatorymediators offers the most comprehensive treatment strategy. However, no such deviceexists at present. A novel, uncoated, polymer pyrolysed synthetic carbon device isproposed which combines the superior adsorption properties of uncoated activatedcarbons with the capacity to manipulate porous structure for controlled adsorption oftarget plasma proteins and polypeptides [5]. Preliminary haemocompatibility andadsorptive capacity was assessed using a carbon matrix prototype
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A Novel Photoplethysmography Sensor for Vital Signs Monitoring from the Human Trachea
Current pulse oximeter sensors can be challenged in working accurately and continuously in situations of reduced periphery perfusion, especially among anaesthetised patients. A novel tracheal photoplethysmography (PPG) sensor has been developed in an effort to address the limitations of current pulse oximeters. The sensor has been designed to estimate oxygen saturation (SpO2) and pulse rate, and has been manufactured on a flexible printed circuit board (PCB) that can adhere to a standard endotracheal (ET) tube. A pilot clinical trial was carried out as a feasibility study on 10 anaesthetised patients. Good quality PPGs from the trachea were acquired at red and infrared wavelengths in all patients. The mean SpO2 reading for the ET tube was 97.1% (SD 1.0%) vs. the clinical monitor at 98.7% (SD 0.7%). The mean pulse rate for the ET sensor was 65.4 bpm (SD 10.0 bpm) vs. the clinical monitor at 64.7 bpm (SD 9.9 bpm). This study supports the hypothesis that the human trachea could be a suitable monitoring site of SpO2 and other physiological parameters, at times where the periphery circulation might be compromised
Plasma Turbulence in the Local Bubble
Turbulence in the Local Bubble could play an important role in the
thermodynamics of the gas that is there. The best astronomical technique for
measuring turbulence in astrophysical plasmas is radio scintillation.
Measurements of the level of scattering to the nearby pulsar B0950+08 by
Philips and Clegg in 1992 showed a markedly lower value for the line-of-sight
averaged turbulent intensity parameter is smaller than normal for two of them, but is completely nominal for
the third. This inconclusive status of affairs could be improved by
measurements and analysis of ``arcs'' in ``secondary spectra'' of pulsars.Comment: Submitted to Space Science Reviews as contribution to Proceedings of
ISSI (International Space Science Institute) workshop "From the Heliosphere
to the Local Bubble". Refereed version accepted for publicatio
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