4,832 research outputs found
Perfectionism and burnout in canoe polo and kayak slalom athletes: The mediating influence of validation and growth-seeking
Recent research suggests that validation-seeking and dimensions of perfectionism may be antecedents of athlete burnout. The present investigation examined whether validation and growth-seeking mediate the relationship between selforiented and socially prescribed perfectionism and burnout. One-hundred and fifty canoe polo and kayak slalom athletes recruited from the top two divisions in the UK completed measures of validation and growth-seeking (GOI), perfectionism (HMPS), and athlete burnout (ABQ). Analyses supported the mediating role of validation-seeking in the relationship between socially prescribed perfectionism and burnout. However, while bivariate correlations indicated that self-oriented perfectionism was positively related to both validation and growth-seeking, neither mediated the self-oriented perfectionism-burnout relationship. The findings suggest that validation-seeking may be an important psychological factor in the development of burnout for athletes exhibiting high levels of socially prescribed perfectionism. The relationship between self-oriented perfectionism and athlete burnout remains unclear because of its association with multiple motives and with socially prescribed perfectionism
Informal care and home-based palliative care: The health-related quality of life of carers
Health is an important factor in the capacity of family and friends (informal carers) to continue providing care for palliative care patients at home. This study investigates associations between the health-related quality of life (HRQOL) of current informal carers and characteristics of the carers and their caregiving situation, in a sample of Australian carers of palliative care patients. The cross-sectional study used the Short Form-36 Health Survey to measure HRQOL. It found carers to have better physical health and worse mental health than the general population. Of 178 carers, 35% reported their health to be worse than it was one year ago. Multiple regression analyses found that the HRQOL of carers whose health had deteriorated in the previous year was associated with the patient's care needs but not the carer's time input, unlike the carers reporting stable health. Clinicians caring for palliative care patients should be alert to the potential health impairments of informal carers and ensure that they are adequately supported in their caregiving role and have access to appropriate treatment and preventive health care. © 2010 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc
Hafnia and alumina on sulphur passivated germanium
In this work hafnia (HfO2) and alumina (Al2O3) films were deposited on germanium, using either water or oxygen plasma as the oxidant, by atomic layer deposition at 250 °C with and without sulphur passivation of the substrate. X-ray photoelectron spectroscopy was carried out to investigate the interface between both HfO2 and Al2O3 films and germanium. The results show that for hafnia and alumina deposited with water on pre-sulphur treated germanium there is negligible GeOx formation when compared to films grown using oxygen plasma. The results support the case for sulphur passivation of the interface
Focus on vulnerable populations and promoting equity in health service utilization ––an analysis of visitor characteristics and service utilization of the Chinese community health service
Background Community health service in China is designed to provide a convenient and affordable primary health service for the city residents, and to promote health equity. Based on data from a large national study of 35 cities across China, we examined the characteristics of the patients and the utilization of community health institutions (CHIs), and assessed the role of community health service in promoting equity in health service utilization for community residents. Methods Multistage sampling method was applied to select 35 cities in China. Four CHIs were randomly chosen in every district of the 35 cities. A total of 88,482 visitors to the selected CHIs were investigated by using intercept survey method at the exit of the CHIs in 2008, 2009, 2010, and 2011. Descriptive analyses were used to analyze the main characteristics (gender, age, and income) of the CHI visitors, and the results were compared with that from the National Health Services Survey (NHSS, including CHIs and higher levels of hospitals). We also analyzed the service utilization and the satisfactions of the CHI visitors. Results The proportions of the children (2.4%) and the elderly (about 22.7%) were lower in our survey than those in NHSS (9.8% and 38.8% respectively). The proportion of the low-income group (26.4%) was apparently higher than that in NHSS (12.5%). The children group had the lowest satisfaction with the CHIs than other age groups. The satisfaction of the low-income visitors was slightly higher than that of the higher-income visitors. The utilization rate of public health services was low in CHIs. Conclusions The CHIs in China appears to fulfill the public health target of uptake by vulnerable populations, and may play an important role in promoting equity in health service utilization. However, services for children and the elderly should be strengthened
Annually resolved North Atlantic marine climate over the last millennium
This is the final version of the article. Available from Nature Publishing Group via the DOI in this record.Owing to the lack of absolutely dated oceanographic information before the modern instrumental period, there is currently significant debate as to the role played by North Atlantic Ocean dynamics in previous climate transitions (for example, Medieval Climate Anomaly-Little Ice Age, MCA-LIA). Here we present analyses of a millennial-length, annually resolved and absolutely dated marine δ(18)O archive. We interpret our record of oxygen isotope ratios from the shells of the long-lived marine bivalve Arctica islandica (δ(18)O-shell), from the North Icelandic shelf, in relation to seawater density variability and demonstrate that solar and volcanic forcing coupled with ocean circulation dynamics are key drivers of climate variability over the last millennium. During the pre-industrial period (AD 1000-1800) variability in the sub-polar North Atlantic leads changes in Northern Hemisphere surface air temperatures at multi-decadal timescales, indicating that North Atlantic Ocean dynamics played an active role in modulating the response of the atmosphere to solar and volcanic forcing.We thank the members of the RV Bjarni Sæmundsson (Cruise No. B05-2006). This work was supported by the NERC-funded ULTRA project (Grant Number NE/H023356/1), NERC-funded CLAM project; (Project No. NE/N001176/1) and EU Millennium Project (Project number 017008). This study is a contribution to the Climate Change Consortium for Wales (C3W). We thank Brian Long (Bangor University) and Dr Julia Becker (Cardiff University) for their technical support, and Dr Manfred Mudelsee for his assistance with the trend analysis. We thank Dr Jessica Tierney and an anonymous reviewer for providing the constructive comments in the reviewing process
4D analysis of the microstructural evolution of Si-based electrodes during lithiation: Time-lapse X-ray imaging and digital volume correlation
Silicon is a promising candidate to substitute or complement graphite as anode material in Li-ion batteries due, mainly, to its high energy density. However, the lithiation/delithiation processes of silicon particles are inherently related to drastic volume changes which, within a battery's physically constrained case, can induce significant deformation of the fundamental components of the battery that can eventually cause it to fail.
In this work, we use non-destructive time-lapse X-ray imaging techniques to study the coupled electrochemo-mechanical phenomena in Li-ion batteries. We present X-ray computed tomography data acquired at different times during the first lithiation of custom-built silicon-lithium battery cells. Microstructural volume changes have been quantified using full 3D strain field measurements from digital volume correlation analysis. Furthermore, the extent of lithiation of silicon particles has been quantified in 3D from the grey-scale of the tomography images. Correlation of the volume expansion and grey-scale changes over the silicon-based electrode volume indicates that the process of lithiation is kinetically affected by the reaction at the Si/LixSi interface
Dirac Equation with Spin Symmetry for the Modified P\"oschl-Teller Potential in -dimensions
We present solutions of the Dirac equation with spin symmetry for vector and
scalar modified P\"oschl-Teller potential within framework of an approximation
of the centrifugal term. The relativistic energy spectrum is obtained using the
Nikiforov-Uvarov method and the two-component spinor wavefunctions are obtain
are in terms of the Jacobi polynomials. It is found that there exist only
positive-energy states for bound states under spin symmetry, and the energy
levels increase with the dimension and the potential range parameter .Comment: 9 pages and 1tabl
Who bullies whom at a garden feeder? Interspecific agonistic interactions of small passerines during a cold winter
Interspecific agonistic interactions are important
selective factors for maintaining ecological niches of
different species, but their outcome is difficult to predict
a priori. Here, we examined the direction and intensity of
interspecific interactions in an assemblage of small passerines
at a garden feeder, focussing on three finch species
of various body sizes. We found that large and mediumsized
birds usually initiated and won agonistic interactions
with smaller species. Also, the frequency of fights increased
with decreasing differences in body size between
the participants. Finally, the probability of engaging in a
fight increased with the number of birds at the feeder
Enhanced switching stability in Ta 2 O 5 resistive RAM by fluorine doping
The effect of fluorine doping on the switching stability of Ta2O5 resistive random access memory devices is investigated. It shows that the dopant serves to increase the memory window and improve the stability of the resistive states due to the neutralization of oxygen vacancies. The ability to alter the current in the low resistance state with set current compliance coupled with large memory window makes multilevel cell switching more favorable. The devices have set and reset voltages of <1V with improved stability due to the fluorine doping. Density functional modelling shows that the incorporation of fluorine dopant atoms at the two-fold O vacancy site in the oxide network removes the defect state in the mid bandgap, lowering the overall density of defects capable of forming conductive filaments. This reduces the probability of forming alternative conducting paths and hence improves the current stability in the low resistance states. The doped devices exhibit more stable resistive states in both dc and pulsed set and reset cycles. The retention failure time is estimated to be a minimum of 2 years for F-doped devices measured by temperature accelerated and stress voltage accelerated retention failure methods
- …
