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Global patterns of accumulation and partitioning of metals in halophytic saltmarsh taxa: a phylogenetic comparative approach
No full textThe current study represents the first attempt to analyse quantitatively, within a phylogenetic framework, uptake and partitioning patterns of copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb) in extant saltmarsh taxa globally, and to assess associations of these patterns with various plant traits indicative of their halophytic adaptations. Despite saltmarsh being diverse taxonomically, most saltmarsh taxa accumulate metals to roots at, or above, unity (> 1). Further, there is significant translocation from roots to shoot for Cu, Zn and Cd (≤ 1), however, Pb is less mobile (TF = 0.65). Patterns of accumulation were similar among families, except greater Cd accumulation to roots in members of Juncaceae. Patterns of uptake to roots and translocation to leaves were broadly similar among plant type, plant form, habitat and photosynthetic mode. Zinc is lower in the leaves of salt-secreting species for some closely related taxa, suggesting some species co-excrete sodium (Na+) and Zn2+ through glands in leaf tissue. Salinity tolerance has no relationship to metal uptake and translocation. Translocation of Zn is greater at lower Zn sediment exposures, reflecting its active uptake and essentiality, but such bias does not affect outcomes of analyses when included as a covariate
Cumulative dispensing of high oral corticosteroid doses for treating asthma in Australia
No full textObjective: To estimate the level of dispensing of oral corticosteroids (OCS) for managing asthma in Australia, with a particular focus on the cumulative dispensing of doses associated with long term toxicity (≥ 1000 mg prednisolone-equivalent). Design: Retrospective cohort study; analysis of 10% random sample of Pharmaceutical Benefits Scheme (PBS) dispensing data. Participants, setting:People aged 12 years or more treated for asthma during 2014–2018, according to dispensing of controller inhaled corticosteroids (ICS). Main outcome measures:Number of people dispensed OCS for managing asthma during 2014–2018; proportion who were cumulatively dispensed at least 1000 mg prednisolone-equivalent. The secondary outcome was the number of people dispensed at least 1000 mg prednisolone-equivalent during 2018, stratified by inhaler controller dose and use. Results:124 011 people had been dispensed at least two prescriptions of ICS during 2014–2018 and met the study definition for asthma, of whom 64 112 (51.7%) had also been dispensed OCS, including 34 580 (27.9% of the asthma group) cumulatively dispensed 1000 mg prednisolone-equivalent or more. Of 138 073 people dispensed OCS at this level, 68 077 (49%) were patients with airway diseases. Dispensing of diabetes and osteoporosis medications was more common for people cumulatively dispensed 1000 mg prednisolone-equivalent or more. During 2018, 4633 people with asthma using high dose ICS controllers were dispensed 1000 mg prednisolone-equivalent or more, for 2316 of whom (50%) controller use was inadequate. Conclusions: Cumulative exposure to OCS in Australia reaches levels associated with toxicity in one-quarter of patients with asthma using ICS. Cumulative dispensing of potentially toxic OCS amounts often accompanies inadequate inhaler controller dispensing. Better approaches are needed to improve adherence to controller therapy, improve outcomes for people with asthma, and to minimise the use and toxicity of OCS
Vanadium(III) acetylacetonate as an efficient soluble catalyst for lithium-oxygen batteries
No full textHigh donor number (DN) solvents in Li—O₂ batteries that dissolve superoxide intermediates in lithium peroxide (Li₂O₂) formation facilitate high capacities at high rates and avoid early cell death. However, their beneficial characteristics also result in an instability towards highly reactive superoxide intermediates. Furthermore, Li—O₂ batteries would deliver a superior energy density, but the multiphase electrochemical reactions are difficult to achieve when operating with only solid catalysts. Herein we demonstrate that vanadium(III) acetylacetonate (V(acac)₃) is an efficient soluble catalyst that can address these problems. During discharge, V(acac)₃ integrates with the superoxide intermediate, accelerating O₂ reduction kinetics and reducing side reactions. During charge, V(acac)₃ acts as a redox mediator that permits efficient oxidation of Li₂O₂. The cells with V(acac)₃ exhibit low overpotential, high rate performance, and considerable cycle stability
The corrosion of mild steel in contact with seawater and sand
No full textThis paper presents selected results from an experimental study of the corrosion of mild steel in contact with chemically inert particles and seawater. Mild steel coupons were buried in particulate media in coupon containers and then immersed in seawater tanks for set periods of time. The full study considers a number of parameters including burial type, pollution level, particle size, and exposure period. The present paper presents mass loss and pit depth results for coupons buried in sand (either completely or partially) and immersed for up to 8 months in seawater dosed with nutrients. The results are compared with corrosion loss and pit depth observations at 20 years exposure on seabed chains in the North Sea. For the present study the coupons partially buried in sand showed the greatest mass loss and the deepest absolute penetration. Coupons that were completely buried showed the least mass loss. The greater mass loss was associated with greater access to oxygen available at the surface of the metal. Reasons and implications are discussed
Level of physical activity among urban adults and the socio-demographic correlates: a population-based cross-sectional study using the global physical activity questionnaire
No full textBackground: Globally, in 2016, 23.3% of adult populations were physically inactive, and it accounts for 9% of the global premature mortality. However, evidence on the level of physical activity was limited in resource-poor settings. This study, therefore, assessed the adult's level of physical activity and its correlates among the urban population in Dire Dawa, eastern Ethiopia. Methods: A total of 872 randomly selected adults of age 25-64 years in Dire Dawa city, eastern Ethiopia, are included in this analysis. The Global Physical Activity Questionnaire (GPAQ) is used to measure physical activity. Individuals are considered physically active when they achieved metabolic equivalent tasks (MET) minutes of 600 or more per week, and otherwise inactive. A binary logistic regression is used to identify the correlates of physical activity. Results: 54.9% (95% confidence interval (CI) 51.6 to 58.2) of adults were physically active, with a higher proportion of men being physically active than women, 63.9% (95% CI 58.1 to 69.3) versus 50.6% (95% CI 46.5 to 54.6). Among the adults who reported doing physical activity, the highest domain-specific contribution to the total physical activity was from activities at workplaces, and leisure-time activities contributed the least. The proportion of adults who engaged in a high-level physical activity was 37.0% (95% CI 33.9 to 40.3). Male adults were 1.45 times (aOR (adjusted odds ratio) =1.45; 95% CI 1.05 to 1.99) more likely to achieve the recommended level of physical activity. In contrary, unemployed adults (aOR = 0.51; 95% CI 0.35 to 0.75) were less likely to perform the recommended level of physical activity to accrue health benefits. Conclusion: Interventions aimed at promoting physical activity should target unemployed and female adults. We recommend further study to explore the contextual factors that hinder physical activity in the study setting
Similarity of energy structure functions in decaying homogeneous isotropic turbulence
No full textAn equilibrium similarity analysis is applied to the transport equation for 〈(δq)²〉 (≡〈(δu)²〉 + 〈(δv)²〉 + 〈(δw)²〉), the turbulent energy structure function, for decaying homogeneous isotropic turbulence. A possible solution requires that the mean energy 〈q²〉 decays with a power-law behaviour (〈q²〉~xm), and the characteristic length scale, which is readily identifiable with the Taylor microscale, varies as x½. This solution is identical to that obtained by George (1992) from the spectral energy equation. The solution does not depend on the actual magnitude of the Taylor-microscale Reynolds number Rλ (~〈q²〉½ λ/ν); Rλ should decay as x⁽m⁺¹⁾/² when m < -1. The solution is tested at relatively low Rλ against grid turbulence data for which m ≃ -1.25 and Rλ decays as x⁻⁰.¹²⁵. Although homogeneity and isotropy are poorly approximated in this flow, the measurements of 〈(δq)²〉 and, to a lesser extent, 〈(δu)(δq)²〉, satisfy similarity reasonably over a significant range of r/λ, where r is the streamwise separation across which velocity increments are estimated. For this range, a similarity-based calculation of the third-order structure function 〈(δu)(δq)²〉 is in reasonable agreement with measurements. Kolmogorov-normalized distributions of 〈(δq)²〉 and 〈(δu)(δq)²〉 collapse only at small r. Assuming homogeneity, isotropy and a Batchelor-type parameterization for 〈(δq)²〉, it is found that Rλ may need to be as large as 10⁶ before a two-decade inertial range is observed
Electrodynamic context of magnetopause dynamics observed by magnetospheric multiscale
No full textMagnetopause observations by Magnetospheric Multiscale (MMS) and Birkeland currents observed by the Active Magnetosphere and Planetary Electrodynamics Response Experiment are used to relate magnetopause encounters to ionospheric electrodynamics. MMS magnetopause crossings on 15 August and 19 September 2015 occurred earthward of expectations due to solar wind ram pressure alone and coincided with equatorward expansion of the Birkeland currents. Magnetopause erosion, consistent with expansion of the polar cap, contributed to the magnetopause crossings. The ionospheric projections of MMS during the events and at times of the magnetopause crossings indicate that MMS observations are related to the main path of flux transport in one case but not in a second. The analysis provides a way to routinely relate in situ observations to the context of in situ convection and flux transport
A race against time: the dementia epidemic
No full textThe global prevalence of dementia is expected to double every two decades. Consequently, there is an urgent need for high-quality research to identify effective strategies for providing optimal care to people with dementia and their carers. Currently, research in dementia care is fragmented, which has resulted in a division between the fields of diagnosis and management of dementia including end-of-life care. For example, interventions which have been developed to improve the well-being of the person with dementia and their families focus on discrete elements of the person and their family's experience, such as symptom management, dealing with emotional issues, or planning for the future. A more integrated approach is needed to address gaps in care across the trajectory, while recognizing the multitude impacts on the person affected and their families. This approach will make a meaningful difference to the well-being of people with dementia and their carers, and reduce the burden of the disease on the individual, their family, and society
Effects of variety support on exercise-related well-being
No full textBackground: The purpose of this study was to experimentally examine the extent to which variety support in a resistance exercise program influences exercise-related well-being among inactive adults. Methods: A sample of 121 inactive university students were randomly assigned and participated in either a high or low variety support 6-week exercise program. Measures of exercise-related perceived variety, positive affect, negative affect, and subjective vitality were completed at baseline, after 3 weeks, and after 6 weeks (i.e. post-test). Results: Through use of structural equation-modelling, the results showed that for those who completed measures at post-test (i.e. n = 55), and for all participants who received variety support (i.e. a modified intention-to-treat analysis; N = 121), exercise-related variety support indirectly explained higher levels of exercise-related positive affect, and subjective vitality, and lower levels of negative affect, through the mediating role of perceived variety. Conclusions: The provision of variety support in a resistance exercise program influences exercise-related well-being through perceptions of variety. Results are discussed in relation to the potential utility of providing variety support to promote exercise-related well-being in people who are physically inactive
Ondansetron and promethazine have differential effects on hypothermic responses to lithium chloride administration and to provocative motion in rats
No full textWe recently reported that provocative motion (rotation in a home cage) causes hypothermic responses in rats, similar to the hypothermic responses associated with motion sickness in humans. Many stimuli inducing emesis in species with an emetic reflex also provoke hypothermia in the rat, therefore we hypothesized that a fall in body temperature may reflect a "nausea-like" state in these animals. As rats do not possess an emetic reflex, we employed a pharmacological approach to test this hypothesis. In humans, motion- and chemically-induced nausea have differential sensitivity to anti-emetics. We thus tested whether the hypothermia induced in rats by provocative motion (rotation at 0.7 Hz) and by the emetic LiCl (63 mg/kg i.p.) have a similar differential pharmacological sensitivity. Both provocations caused a comparable robust fall in core body temperature (-1.9 ± 0.3°C and -2.0 ± 0.2°C for chemical and motion provocations, respectively). LiCl(-)induced hypothermia was completely prevented by ondansetron (2mg/kg, i.p., a 5-HT3 receptor antagonist that reduces cancer chemotherapy-induced nausea and vomiting), but was insensitive to promethazine (10 mg/kg, i.p., a predominantly histamine-H1 and muscarinic receptor antagonist that is commonly used to treat motion sickness). Conversely, motion-induced hypothermia was unaffected by ondansetron but promethazine reduced the rate of temperature decline from 0.20 ± 0.02 to 0.11 ± 0.03°C/min (P < 0.05) with a trend to decrease the magnitude. We conclude that this differential pharmacological sensitivity of the hypothermic responses of vestibular vs. chemical etiology in rats mirrors the observations in other pre-clinical models and humans, and thus supports the idea that a "nausea-like" state in rodents is associated with disturbances in thermoregulation