208 research outputs found

    Impacts of dieback at Pine Lake, Tasmania

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    The possibility of a new plant disease in alpine plant communities was identified in 1994, following an investigation of dead and dying plants in the Central Plateau Conservation Area. Seven areas of dieback were identified within the affected catchment and monitored. Symptoms included leaf discolouration, loss of foliage and plant death. No disease of this type has previously been recorded in the Australian alpine environment. Temporal and spatial patterns in disease development along with evidence of lesions on plant roots suggested a soil and water-borne pathogen could be contributing to the dieback. A species of Phytophthora was isolated from plant material collected at the site. Investigations have focussed on whether plants at the limits of their range have been more susceptible to a combination of below-average rainfall, above-average temperatures and the presence of pathogens. Initial rapid development of disease symptoms suggested the potential for local extinction of species, including Tasmanian endemics such as Athrotaxis cupressoides, and significant alteration to community structure through a loss or substantial reduction in the tree and shrub layers. However, longer term monitoring suggests short-term disease events followed by recovery of surviving plants with only localised impacts. Management actions have been concentrated on containment, monitoring impacts and investigation of the cause of the dieback

    Hybrid in vitro diffusion cell for simultaneous evaluation of hair and skin decontamination: temporal distribution of chemical contaminants

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    Most casualty or personnel decontamination studies have focused on removing contaminants from the skin. However, scalp hair and underlying skin are the most likely areas of contamination following airborne exposure to chemicals. The aim of this study was to investigate the interactions of contaminants with scalp hair and underlying skin using a hybrid in vitro diffusion cell model. The in vitro hybrid test system comprised “curtains” of human hair mounted onto sections of excised porcine skin within a modified diffusion cell. The results demonstrated that hair substantially reduced underlying scalp skin contamination and that hair may provide a limited decontamination effect by removing contaminants from the skin surface. This hybrid test system may have application in the development of improved chemical incident response processes through the evaluation of various hair and skin decontamination strategies.Peer reviewedFinal Published versio

    Evaluation of absorbent materials for use as ad hoc dry decontaminants during mass casualty incidents as part of the UK's Initial Operational Response (IOR)

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    The UK's Initial Operational Response (IOR) is a revised process for the medical management of mass casualties potentially contaminated with hazardous materials. A critical element of the IOR is the introduction of immediate, on-scene disrobing and decontamination of casualties to limit the adverse health effects of exposure. Ad hoc cleansing of the skin with dry absorbent materials has previously been identified as a potential means of facilitating emergency decontamination. The purpose of this study was to evaluate the in vitro oil and water absorbency of a range of materials commonly found in the domestic and clinical environments and to determine the effectiveness of a small, but representative selection of such materials in skin decontamination, using an established ex vivo model. Five contaminants were used in the study: methyl salicylate, parathion, diethyl malonate, phorate and potassium cyanide. In vitro measurements of water and oil absorbency did not correlate with ex vivo measurements of skin decontamination. When measured ex vivo, dry decontamination was consistently more effective than a standard wet decontamination method (“rinse-wipe-rinse”) for removing liquid contaminants. However, dry decontamination was ineffective against particulate contamination. Collectively, these data confirm that absorbent materials such as wound dressings and tissue paper provide an effective, generic capability for emergency removal of liquid contaminants from the skin surface, but that wet decontamination should be used for non-liquid contaminants

    Initial Effects of Deforestation on Herbaceous Species Composition in Grassy Woodlands of the Northern Tablelands, NSW Australia

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    Limited information on the initial effects of clearing and thinning on herbaceous vegetation of grassy temperate eucalyptus forests exists. The aim of this investigation is to study the initial changes in species composition following clearing and thinning. A deforestation experiment was established where clearing, thinning of 50% of canopy cover and control treatments were established. In the open-forests, patterns in herbaceous species composition were strongly influenced by the presence of trees, with weeping wheat grass (Microlaena stipoides) dominant, whereas wiregrass (Aristida ramosa) dominated interspaces and canopy gaps. Immediately following clearing, significant changes in the herbaceous species composition were observed, with 26 new species recorded. The original vegetation pattern was lost, being replaced by Cyperaceae and Juncaceae, and a large number of invasive ruderal species. A state and transition model that describes the changes in composition is presented

    Sensing RF fields with a distant stand-alone Rydberg-atomic receiver

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    We combine a rubidium vapour cell with a corner-cube prism reflector to form a passive RF receiver, allowing the detection of microwave signals at a location distant from the active components required for atomic sensing. This compact receiver has no electrical components and is optically linked to the active base station by a pair of free-space laser beams that establish an electromagnetically induced transparency scenario in the atomic vapour. Microwave signals at the receiver location are imprinted onto an optical signal which is detected at the base station. Our stand-alone receiver architecture adds important flexibility to Rydberg-atom based sensing technologies, which are currently subject to significant attention. We demonstrate a ~20 m link with no particular effort and foresee significant future prospects of achieving a much larger separation between receiver and base station

    Plastic Surgery After Gastric Bypass Improves Long-Term Quality of Life

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    Background: Excess skin after massive weight loss impairs patient's health-related quality of life (HRQoL). Therefore, body-contouring surgeries can be proposed. However, few data exist concerning the effect of body contouring after bariatric surgery on HRQoL, including control group with a long-term follow-up. Methods: In a prospective study, 98 consecutive patients who had body contouring after gastric bypass for obesity (BMI > 40) were included (group A). A matched control-group containing 102 patients who had only gastric bypass was selected (group B). HRQoL was measured by Moorehead-Ardelt questionnaire before (group A1) and after (A2) body contouring, and at different time points for group B until 8years post-gastric bypass. To evaluate the effect of body contouring by two parallel methods, HRQoL was compared between groups A1 and A2, and between A2 and B. Results: We found that body contouring procedures improved significantly patients' HRQoL, in comparison to those who had only gastric bypass. Of the patients who had body contouring (group A2), 57% evaluated their HRQoL "much better” in comparison to only 22% of patients before body contouring (group A1) or those who never had body contouring (group B) (p < 0.001). The improvement was significant in all sub-domains of HRQoL: self-esteem, social life, work ability, sexual activity and physical activity (p < 0.001), and remained stable over time. Conclusions: Our study confirms the important role of plastic surgery in treatment of patients after massive weight loss. We demonstrated that body contouring, despite important scars, significantly improves satisfaction and HRQoL of patients after gastric bypass. Therefore, the treatment of morbid obesity should not be deemed achieved unless plastic surgery has been considere

    Reappraisal of the options for colorectal cancer screening

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    Nasal continuous positive airways pressure in the management of sleep apnoea

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    Human volunteer study of the decontamination of chemically contaminated hair and the consequences for systemic exposure

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    The decontamination of exposed persons is a priority following the release of toxic chemicals. Efficacious decontamination reduces the risk of harm to those directly affected and prevents the uncontrolled spread of contamination. Human studies examining the effectiveness of emergency decontamination procedures have primarily focused on decontaminating skin, with few examining the decontamination of hair and scalp. We report the outcome of two studies designed to evaluate the efficacy of current United Kingdom (UK) improvised, interim and specialist mass casualty decontamination protocols when conducted in sequence. Decontamination efficacy was evaluated using two chemical simulants, methyl salicylate (MeS) and benzyl salicylate (BeS) applied to and recovered from the hair of volunteers. Twenty-four-hour urinary MeS and BeS were measured as a surrogate for systemic bioavailability. Current UK decontamination methods performed in sequence were partially effective at removing MeS and BeS from hair and underlying scalp. BeS and MeS levels in urine indicated that decontamination had no significant effect on systemic exposure raising important considerations with respect to the speed of decontamination. The decontamination of hair may therefore be challenging for first responders, requiring careful management of exposed persons following decontamination. Further work to extend these studies is required with a broader range of chemical simulants, a larger group of volunteers and at different intervention times

    Demonstration of Universal Parametric Entangling Gates on a Multi-Qubit Lattice

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    We show that parametric coupling techniques can be used to generate selective entangling interactions for multi-qubit processors. By inducing coherent population exchange between adjacent qubits under frequency modulation, we implement a universal gateset for a linear array of four superconducting qubits. An average process fidelity of F=93%\mathcal{F}=93\% is estimated for three two-qubit gates via quantum process tomography. We establish the suitability of these techniques for computation by preparing a four-qubit maximally entangled state and comparing the estimated state fidelity against the expected performance of the individual entangling gates. In addition, we prepare an eight-qubit register in all possible bitstring permutations and monitor the fidelity of a two-qubit gate across one pair of these qubits. Across all such permutations, an average fidelity of F=91.6±2.6%\mathcal{F}=91.6\pm2.6\% is observed. These results thus offer a path to a scalable architecture with high selectivity and low crosstalk
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