1,063 research outputs found

    Acute and Chronic Toxicity of Selenium to Estuarine Organisms

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    Acute toxicity tests were conducted with selenium and five estuarine organIsms, and chronic or early life stage tests were conducted with mysid shrimp (Mysidopsis bahia) and sheepshead minnows (Cyprlnodon varlegatus). The concentrations of selenium lethal to 50% of the test animals after 96 hours of exposure (96-hour LC50\u27s) ranged from 1.2 mg/l for brown shrimp (Penaeus aztecus) to 7.4 mg/l for sheepshead mlnnows. The maximum acceptable toxicant concentration (MATC) was \u3e 0.14 \u3c 0.32 mg/l for mysid shrimp and \u3e 0.47 \u3c 0.97 mg/l for sheepshead minnows. The application factor limits for mysid shrimp and sheepshead minnows were 0.09-0.21 and 0.06-0.13, respectively

    Short horizons and obesity futures: Disjunctures between public health interventions and everyday temporalities

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    This paper examines the spatio-temporal disjuncture between ‘the future’ in public health obesity initiatives and the embodied reality of eating. Drawing upon ethnographic fieldwork in a disadvantaged community in South Australia (August 2012–July 2014), we argue that the future oriented discourses of managing risk employed in obesity prevention programs have limited relevance to the immediacy of poverty, contingencies and survival that mark people's day to day lives. Extending Bourdieu's position that temporality is a central feature of practice, we develop the concept of short horizons to offer a theoretical framework to articulate the tensions between public health imperatives of healthy eating, and local ‘tastes of necessity’. Research undertaken at the time of Australia's largest obesity prevention program (OPAL) demonstrates that pre-emptive and risk-based approaches to health can fail to resonate when the future is not within easy reach. Considering the lack of evidence for success of obesity prevention programs, over-reliance on appeals to ‘the future’ may be a major challenge to the design, operationalisation and success of interventions. Attention to local rather than future horizons reveals a range of innovative strategies around everyday food and eating practices, and these capabilities need to be understood and supported in the delivery of obesity interventions. We argue, therefore, that public health initiatives should be located in the dynamics of a living present, tailored to the particular, localised spatio-temporal perspectives and material circumstances in which people live.Megan Warin, Tanya Zivkovic, Vivienne Moore, Paul R. Ward, Michelle Jone

    Triply Threaded [4]Rotaxanes

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    [4]Rotaxanes featuring three axles threaded through a single ring have been prepared through active metal template synthesis. Nickel-catalyzed sp3-sp3 homocouplings of alkyl bromide ‘half threads’ through 37- and 38-membered 2,2':6',2"-terpyridyl macrocycles generates triply-threaded [4]rotaxanes in up to 11 % yield. An analogous 39-membered macrocycle produced no rotaxane products under similar conditions. The constitutions of the [4]rotaxanes were determined by NMR spectroscopy and mass spectrometry. Doubly-threaded [3]rotaxanes were also obtained from the reactions but no [2]rotaxanes were isolated, suggesting that upon demetallation the axle of a singly-threaded rotaxane can slip through a macrocycle that is sufficiently large to accommodate three threads

    On Epstein's trajectory model of non-relativistic quantum mechanics

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    In 1952 Bohm presented a theory about non-relativistic point-particles moving along deterministic trajectories and showed how it reproduces the predictions of standard quantum theory. This theory was actually presented before by de Broglie in 1926, but Bohm's particular formulation of the theory inspired Epstein to come up with a different trajectory model. The aim of this paper is to examine the empirical predictions of this model. It is found that the trajectories in this model are in general very different from those in the de Broglie-Bohm theory. In certain cases they even seem bizarre and rather unphysical. Nevertheless, it is argued that the model seems to reproduce the predictions of standard quantum theory (just as the de Broglie-Bohm theory).Comment: 12 pages, no figures, LaTex; v2 minor improvement

    Identifying the mechanisms underpinning recognition of structured sequences of action

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    © 2012 The Experimental Psychology SocietyWe present three experiments to identify the specific information sources that skilled participants use to make recognition judgements when presented with dynamic, structured stimuli. A group of less skilled participants acted as controls. In all experiments, participants were presented with filmed stimuli containing structured action sequences. In a subsequent recognition phase, participants were presented with new and previously seen stimuli and were required to make judgements as to whether or not each sequence had been presented earlier (or were edited versions of earlier sequences). In Experiment 1, skilled participants demonstrated superior sensitivity in recognition when viewing dynamic clips compared with static images and clips where the frames were presented in a nonsequential, randomized manner, implicating the importance of motion information when identifying familiar or unfamiliar sequences. In Experiment 2, we presented normal and mirror-reversed sequences in order to distort access to absolute motion information. Skilled participants demonstrated superior recognition sensitivity, but no significant differences were observed across viewing conditions, leading to the suggestion that skilled participants are more likely to extract relative rather than absolute motion when making such judgements. In Experiment 3, we manipulated relative motion information by occluding several display features for the duration of each film sequence. A significant decrement in performance was reported when centrally located features were occluded compared to those located in more peripheral positions. Findings indicate that skilled participants are particularly sensitive to relative motion information when attempting to identify familiarity in dynamic, visual displays involving interaction between numerous features

    X-wave mediated instability of plane waves in Kerr media

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    Plane waves in Kerr media spontaneously generate paraxial X-waves (i.e. non-dispersive and non-diffractive pulsed beams) that get amplified along propagation. This effect can be considered a form of conical emission (i.e. spatio-temporal modulational instability), and can be used as a key for the interpretation of the out of axis energy emission in the splitting process of focused pulses in normally dispersive materials. A new class of spatio-temporal localized wave patterns is identified. X-waves instability, and nonlinear X-waves, are also expected in periodical Bose condensed gases.Comment: 4 pages, 6 figure

    Statin therapy/ HMG CO-A reductase inhibitor (statins) treatment in the prevention of coronary heart disease

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    Alcohol consumption and perceptions of health risks during COVID-19: a qualitative study of middle-aged women in South Australia

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    Australian women's alcohol consumption has increased in frequency during COVID-19. Research suggests this is to cope with stress resulting from the pandemic and COVID-19 countermeasures that require social distancing. This is a critical public health concern because increased alcohol consumption, even for a short period, increases the myriad longer-term health risks associated with cumulative exposure to alcohol. This paper provides unique qualitative evidence of how health risk perceptions are re-focused toward the shorter-term during the pandemic, through analysis of interviews with 40 middle-aged Australian women (aged 45–64) representing a range of self-perceived drinking status' (“occasional”/“light”/“moderate”/“heavy”) before and then during the pandemic (n = 80 interviews). Our analysis captures women's risk horizons drifting away from the uncertain longer-term during COVID-19, toward the immediate need to “get through” the pandemic. We show how COVID-19 has increased the perceived value of consuming alcohol among women, particularly when weighed up against the social and emotional “costs” of reducing consumption. Our findings have implications for the delivery of alcohol-related health risk messages designed for middle-aged women both during, and into the recovery phases of the pandemic, who already consume more alcohol and experience more alcohol-related health risk than women in other age groups.Belinda Lunnay, Kristen Foley, Samantha B. Meyer, Megan Warin, Carlene Wilson, Ian Olver ... et al

    Social class and changes in Australian women's affect and alcohol consumption during COVID-19

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    Introduction: Before the pandemic, mid-life women in Australia were among the “heaviest” female alcohol consumers, giving rise to myriad preventable health risks. This paper uses an innovative model of social class within a sample of Australian women to describe changes in affective states and alcohol consumption patterns across two time points during COVID-19. Methods: Survey data were collected from Australian mid-life women (45–64 years) at two time points during COVID-19—May 2020 (N = 1,218) and July 2020 (N = 799). We used a multi-dimensional model for measuring social class across three domains—economic capital (income, property and assets), social capital (social contacts and occupational prestige of those known socially), and cultural capital (level of participation in various cultural activities). Latent class analysis allowed comparisons across social classes to changes in affective states and alcohol consumption patterns reported at the two time points using alcohol consumption patterns as measured by the Alcohol Use Disorders Identification Test—Consumption (AUDIT-C) and its component items. Results: Seven social classes were constructed, characterized by variations in access to capital. Affective states during COVID-19 differed according to social class. Comparing between the survey time points, feeling fearful/anxious was higher in those with high economic and cultural capital and moderate social capital (“emerging affluent”). Increased depression was most prominent in the class characterized by the highest volumes of all forms of capital (“established affluent”). The social class characterized by the least capital (“working class”) reported increased prevalence of uncertainty, but less so for feeling fearful or anxious, or depressed. Women's alcohol consumption patterns changed across time during the pandemic. The “new middle” class—a group characterized by high social capital (but contacts with low prestige) and minimal economic capital—had increased AUDIT-C scores. Conclusion: Our data shows the pandemic impacted women's negative affective states, but not in uniform ways according to class. It may explain increases in alcohol consumption among women in the emerging affluent group who experienced increased feelings or fear and anxiety during the pandemic. This nuanced understanding of the vulnerabilities of sub-groups of women, in respect to negative affect and alcohol consumption can inform future pandemic policy responses designed to improve mental health and reduce the problematic use of alcohol. Designing pandemic responses segmented for specific audiences is also aided by our multi-dimensional analysis of social class, which uncovers intricate differences in affective states amongst sub-groups of mid-life women.Belinda Lunnay, Barbara Toson, Carlene Wilson, Emma R. Miller, Samantha Beth Meyer, Ian N. Olver, Kristen Foley, Jessica A. Thomas and Paul Russell War

    COVID-19, alcohol consumption and stockpiling practises in midlife women: repeat surveys during lockdown in Australia and the United Kingdom

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    Introduction: This project examined the impact of COVID-19 and associated restrictions on alcohol practises (consumption and stockpiling), and perceptions of health risk among women in midlife (those aged 45–64 years). Methods: We collected online survey data from 2,437 midlife women in the United Kingdom (UK) and Australia in May 2020, recruited using a commercial panel, in the early days of mandated COVID-19 related restrictions in both countries. Participants were surveyed again (N = 1,377) in July 2020, at a time when COVID-19 restrictions were beginning to ease. The surveys included the Alcohol Use Disorder Identification Test—Consumption (AUDIT-C) and questions alcohol stockpiling. Analysis involved a range of univariate and multivariate techniques examining the impact of demographic variables and negative affect on consumption and acquisition outcomes. Results: In both surveys (May and July), UK women scored higher than Australian women on the AUDIT-C, and residence in the UK was found to independently predict stockpiling of alcohol (RR: 1.51; 95% CI: 1.20, 1.91). Developing depression between surveys (RR: 1.53; 95% CI: 1.14, 2.04) and reporting pessimism (RR: 1.42; 95% CI: 1.11, 1.81), and fear/anxiety (RR: 1.33; 95% CI: 1.05, 1.70) at the beginning of the study period also predicted stockpiling by the end of the lockdown. Having a tertiary education was protective for alcohol stockpiling at each time point (RR: 0.69; 95% CI: 0.54, 0.87). Conclusions: COVID-19 was associated with increases in risky alcohol practises that were predicted by negative emotional responses to the pandemic. Anxiety, pessimism and depression predicted stockpiling behaviour in UK and Australian women despite the many demographic and contextual differences between the two cohorts. Given our findings and the findings of others that mental health issues developed or were exacerbated during lockdown and may continue long after that time, urgent action is required to address a potential future pandemic of alcohol-related harms.Emma R. Miller, Ian N. Olver, Carlene J. Wilson, Belinda Lunnay, Samantha B. Meyer, Kristen Foley ... et al
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