66 research outputs found

    The catatonic dilemma expanded

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    Catatonia is a common syndrome that was first described in the literature by Karl Kahlbaum in 1874. The literature is still developing and remains unclear on many issues, especially classification, diagnosis, and pathophysiology. Clinicians caring for psychiatric patients with catatonic syndromes continue to face many dilemmas in diagnosis and treatment. We discuss many of the common problems encountered in the care of a catatonic patient, and discuss each problem with a review of the literature. Focus is on practical aspects of classification, epidemiology, differential diagnosis, treatment, medical comorbidity, cognition, emotion, prognosis, and areas for future research in catatonic syndromes

    Critical Invasion Science: Weeds, Pests, and Aliens

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    The study of invasive plants and animals calls strongly for a critical approach due to the deeply social nature of invasion landscapes, the power relations affecting the science of invasions, and the differential impacts of weed or pest control on lives and landscapes. I first explore what a “critical” invasion science means. Then I investigate several aspects of invasion science ripe for critical analysis: the history of the science (to understand what the science is doing and why), the terminology and categories of analysis, and the highly contested social, political, and ethical context within which invasion management takes place. I conclude with four proposals for further work in critical invasion science and examples of the types of questions it might ask

    Effects of fluoxetine on functional outcomes after acute stroke (FOCUS): a pragmatic, double-blind, randomised, controlled trial

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    Background Results of small trials indicate that fluoxetine might improve functional outcomes after stroke. The FOCUS trial aimed to provide a precise estimate of these effects. Methods FOCUS was a pragmatic, multicentre, parallel group, double-blind, randomised, placebo-controlled trial done at 103 hospitals in the UK. Patients were eligible if they were aged 18 years or older, had a clinical stroke diagnosis, were enrolled and randomly assigned between 2 days and 15 days after onset, and had focal neurological deficits. Patients were randomly allocated fluoxetine 20 mg or matching placebo orally once daily for 6 months via a web-based system by use of a minimisation algorithm. The primary outcome was functional status, measured with the modified Rankin Scale (mRS), at 6 months. Patients, carers, health-care staff, and the trial team were masked to treatment allocation. Functional status was assessed at 6 months and 12 months after randomisation. Patients were analysed according to their treatment allocation. This trial is registered with the ISRCTN registry, number ISRCTN83290762. Findings Between Sept 10, 2012, and March 31, 2017, 3127 patients were recruited. 1564 patients were allocated fluoxetine and 1563 allocated placebo. mRS data at 6 months were available for 1553 (99·3%) patients in each treatment group. The distribution across mRS categories at 6 months was similar in the fluoxetine and placebo groups (common odds ratio adjusted for minimisation variables 0·951 [95% CI 0·839–1·079]; p=0·439). Patients allocated fluoxetine were less likely than those allocated placebo to develop new depression by 6 months (210 [13·43%] patients vs 269 [17·21%]; difference 3·78% [95% CI 1·26–6·30]; p=0·0033), but they had more bone fractures (45 [2·88%] vs 23 [1·47%]; difference 1·41% [95% CI 0·38–2·43]; p=0·0070). There were no significant differences in any other event at 6 or 12 months. Interpretation Fluoxetine 20 mg given daily for 6 months after acute stroke does not seem to improve functional outcomes. Although the treatment reduced the occurrence of depression, it increased the frequency of bone fractures. These results do not support the routine use of fluoxetine either for the prevention of post-stroke depression or to promote recovery of function. Funding UK Stroke Association and NIHR Health Technology Assessment Programme

    Survival of Escherichia coli in stormwater biofilters

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    Biofilters are widely adopted in Australia for stormwater treatment, but the reported removal of common faecal indicators (such as Escherichia coli (E. coli)) varies from net removal to net leaching. Currently, the underlying mechanisms that govern the faecal microbial removal in the biofilters are poorly understood. Therefore, it is important to study retention and subsequent survival of faecal microorganisms in the biofilters under different biofilter designs and operational characteristics. The current study investigates how E. coli survival is influenced by temperature, moisture content, sunlight exposure and presence of other microorganisms in filter media and top surface sediment. Soil samples were taken from two different biofilters to investigate E. coli survival under controlled laboratory conditions. Results revealed that the presence of other microorganisms and temperature are vital stressors which govern the survival of E. coli captured either in the top surface sediment or filter media, while sunlight exposure and moisture content are important for the survival of E. coli captured in the top surface sediment compared to that of the filter media. Moreover, increased survival was found in the filter media compared to the top sediment, and sand filter media was found be more hostile than loamy sand filter media towards E. coli survival. Results also suggest that the contribution from the tested environmental stressors on E. coli survival in biofilters will be greatly affected by the seasonality and may vary from one site to another.</p

    Evaluating Escherichia coli removal performance in stormwater biofilters: A preliminary modelling approach

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    Stormwater biofilters are not currently optimised for pathogen removal since the behaviour of these pollutants within the stormwater biofilters is poorly understood. Modelling is a common way of optimising these systems, which also provides a better understanding of the major processes that govern the pathogen removal. This paper provides an overview of a laboratory-scale study that investigated how different design and operational conditions impact pathogen removal in the stormwater biofilters. These data were then used to develop a modelling tool that can be used to optimise the design and operation of the stormwater biofilters. The model uses continuous simulations where adsorption and desorption were dominant during wet weather periods and first order die-off kinetics were significant in dry periods between the wet weather events. Relatively high Nash Sutcliffe Efficiencies (>0.5) indicate that the calibrated model is in good agreement with observed data and the optimised model parameters were comparable with values reported in the literature. The model's sensitivity is highest towards the adsorption process parameter followed by the die-off and desorption rate parameters, which implies that adsorption is the governing process of the model. Vegetation is found to have an impact on the wet weather processes since the adsorption and desorption parameters vary significantly with the different plant configurations. The model is yet to be tested against field data and needs to be improved to represent the effect of some other biofilter design configurations, such as the inclusion of the submerged zone.</p

    Biofiltration for stormwater harvesting: Comparison of Campylobacter spp. and Escherichia coli removal under normal and challenging operational conditions

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    Knowledge of pathogen removal in stormwater biofilters (also known as stormwater bioretention systems or rain gardens) has predominately been determined using bacterial indicators, and the removal of reference pathogens in these systems has rarely been investigated. Furthermore, current understanding of indicator bacteria removal in these systems is largely built upon laboratory-scale work. This paper examines whether indicator organism removal from urban stormwater using biofilters in laboratory settings are representative of the removal of pathogens in field conditions, by studying the removal of Escherichia coli (a typical indicator microorganism) and Campylobacter spp. (a typical reference pathogen) from urban stormwater by two established field-scale biofilters. It was found that E. coli log reduction was higher than that of Campylobacter spp. in both biofilters, and that there was no correlation between E. coli and Campylobacter spp. log removal performance. This confirms that E. coli behaves significantly differently to this reference pathogen, reinforcing that single organisms should not be employed to understand faecal microorganism removal in urban stormwater treatment systems. The average reduction in E. coli from only one of the tested biofilters was able to meet the log reduction targets suggested in the current Australian stormwater harvesting guidelines for irrigating sports fields and golf courses. The difference in the performance of the two biofilters is likely a result of a number of design and operational factors; the most important being that the biofilter that did not meet the guidelines was tested using extremely high influent volumes and microbial concentrations, and long antecedent dry weather periods. As such, the E. coli removal performances identified in this study confirmed laboratory findings that inflow concentration and antecedent dry period impact overall microbial removal. In general, this paper emphasizes the need for the validation of stormwater harvesting systems, namely, the testing of treatment systems under challenging operational conditions using multiple indicators and reference pathogens.</p

    Plants that can kill; improving E. coli removal in stormwater treatment systems using Australian plants with antibacterial activity

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    Sustainable stormwater treatment systems remove pollutants using low energy, low maintenance and low cost solutions. Inactivation due to biotic stressors is one of the processes that govern the removal of faecal microorganisms in these systems. One such stress is the possible production of antimicrobial compounds by plants growing in sustainable stormwater treatment systems, potentially enhancing the removal of faecal pathogens. To this end, this study has investigated the antimicrobial potential of 17 Australian native plant species that are suitable for application in these systems but have not been tested for their antimicrobial activity within their seed exudates, seed extracts and/or seedling extracts. The extracts and exudates were tested using the agar well diffusion method. Nine of the selected plant species inhibited the growth of Escherichia coli. Among of the antibacterial plants, Melaleuca ericifolia, which has been previously applied in stormwater treatment systems, can be a suitable candidate for further study as it demonstrated antibacterial activity within all tested components. This species should be utilised in stormwater treatment facilities due to its effective nitrogen uptake, maintenance of hydraulic conductivity, and due to its potential effectiveness at inactivating microbial pathogens.</p

    Isolation and toxicity of cylindrospermopsis raciborskii from an ornamental lake.

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    In Australia, the tropical/subtropical cyanobacterium Cylindrospermopsis raciborskii forms substantial blooms in some drinking water supply reservoirs, rivers and recreational water bodies during the warmer months of the year. This paper describes the isolation, culture and toxicity characterisation of Cylindrospermopsis from a water bloom in a small lake in NSW, Australia. The cyanobacterium grew as straight trichomes terminating with a characteristic heterocyst. The toxic alkaloid cylindrospermopsin was separated and identified by high-performance liquid chromatography at a concentration of 5.5 mg/g dry cells, 0.026 pg/cell. Intraperitoneal injection of sonicated cells caused liver, kidney, intestinal and lung damage, with an LD50 of 52 mg cells/kg mouse body weight at 24 hr, and 32 mg/kg at 7 days. The 24 hr mouse toxicity is not consistent with previous studies using pure cylindrospermopsin, and is suggestive of other toxic compounds in this isolate
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