4,682 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
Inflammatory gene expression profiles in sporadic, familial and TREM2 variant Alzheimer's disease
A projective Dirac operator on CP^2 within fuzzy geometry
We propose an ansatz for the commutative canonical spin_c Dirac operator on
CP^2 in a global geometric approach using the right invariant (left action-)
induced vector fields from SU(3). This ansatz is suitable for noncommutative
generalisation within the framework of fuzzy geometry. Along the way we
identify the physical spinors and construct the canonical spin_c bundle in this
formulation. The chirality operator is also given in two equivalent forms.
Finally, using representation theory we obtain the eigenspinors and calculate
the full spectrum. We use an argument from the fuzzy complex projective space
CP^2_F based on the fuzzy analogue of the unprojected spin_c bundle to show
that our commutative projected spin_c bundle has the correct
SU(3)-representation content.Comment: reduced to 27 pages, minor corrections, minor improvements, typos
correcte
The application of a vacuum ultraviolet Fourier transform spectrometer and synchrotron radiation source to measurements of: IV. The β(6,0) and γ(3,0) bands of NO
The β(6,0) and the γ(3,0) bands of NO near 198 nm were analyzed using the VUV FT spectrometer with synchrotron radiation for the background source. Accurate line positions and line strengths of the rotational lines were retrieved from the FT spectra. The rotational term values of the B 2∏ r (v=6) and A 2Σ + (v=3) levels were evaluated and fed to a least squares fitting program to obtain accurate molecular constants of these levels.published_or_final_versio
Application of a VUV fourier transform spectrometer and synchrotron radiation source to measurements of. VI. The ε(0,0) band of NO
The analysis of the ε(0,0) band around 187.6 nm was reported using the VUV FTS with synchrotron radiation for the background source. Due to the capability of the combintion of instruments, These were the first high-resolution quantitative measurements of line positions and intensities of the rotational lines of the ε(0,0) band. The determination of the band oscillator strengths of the band was performed using line-by-line measurements, because the resolution of the present experiment was comparable to the Doppler widths.published_or_final_versio
The application of a VUV Fourier transform spectrometer and synchrotron radiation source to measurements of: II. The δ(1,0) band of NO
Line-by-line photoabsorption cross-sections of the NO δ(1,0) band were measured with the VUV Fourier transform spectrometer from Imperial College, London, using synchrotron radiation at Photon Factory, KEK, Japan, as a continuum light source. The analysis of the NO δ(1,0) band provides accurate rotational line positions and term values as well as the photoabsorption cross-sections. The molecular constants of the C(1)2 II level are found to be T0 = 54 690.155±0.03 cm–1, Bv = 1.944 06±0.000 62 cm–1, Dv = (5.91±0.42)×10–5 cm–1, AD = –0.0187±0.0050 cm–1, p = –0.0189±0.0037 cm–1, and q = –0.015 21±0.000 20 cm–1. The sum of the line strengths for all rotational transitions of the NO δ(1,0) band is determined as 4.80×10–15 cm2 cm–1, corresponding to a band oscillator strength of 0.0054±0.0003.published_or_final_versio
The application of a VUV Fourier transform spectrometer and synchrotron radiation source to measurements of: I. the β(9,0) band of NO
State-of-the-art models of the vacuum ultraviolet (VUV) absorbing properties of the atmosphere call for absorption cross sections with detail on the scale of the Doppler widths. As a consequence, spectroscopic data at resolving powers of the order of 10 6 are needed. To meet these requirements in the vacuum ultraviolet region, we have used the VUV Fourier transform spectrometer from Imperial College, London, at the synchrotron radiation facility at Photon Factory, KEK, Japan, to measure photoabsorption cross sections of NO from 195 to 160 nm, and of O 2 from 185 to 175 nm. The analysis of the β(9,0) band (B 2Π r-X 2Π r) of NO provides accurate rotational line positions and term values. Molecular constants of the B(9) 2Π level are T 0=54205.097±0.012cm -1, A=45.320±0.021cm -1, B υ=1.01672±0.00016cm -1, D υ=(10.61±0.32)×10 -6cm -1, and A D=0.00122±0.00011cm -1. The rotational line strengths and the branching ratios are also presented. The band oscillator strength is obtained as f=2.65×10 -4. © 1998 American Institute of Physics.published_or_final_versio
Mechanical Systems with Symmetry, Variational Principles, and Integration Algorithms
This paper studies variational principles for mechanical systems with symmetry and their applications to integration algorithms. We recall some general features of how to reduce variational principles in the presence of a symmetry group along with general features of integration algorithms for mechanical systems. Then we describe some integration algorithms based directly on variational principles using a
discretization technique of Veselov. The general idea for these variational integrators is to directly discretize Hamilton’s principle rather than the equations of motion in a way that preserves the original systems invariants, notably the symplectic form and, via a discrete version of Noether’s theorem, the momentum map. The resulting mechanical integrators are second-order accurate, implicit, symplectic-momentum algorithms. We apply these integrators to the rigid body and the double spherical pendulum to show that the techniques are competitive with existing integrators
Predictors of long-term change in adult cognitive performance: systematic review and data from the Northern Finland Birth Cohort 1966
Objective: Several social life events and challenges have an impact on cognitive development. Our goal was to analyze the predictors of change in cognitive performance in early midlife in a general population sample. Additionally, systematic literature review was performed. Method: The study sample was drawn from the Northern Finland Birth Cohort 1966 at the ages of 34 and 43 years. Primary school performance, sociodemographic factors and body mass index (BMI) were used to predict change in cognitive performance measured by the California Verbal Learning Test, Visual Object Learning Test, and Abstraction Inhibition and Working Memory task. Analyses were weighted by gender and education, and p-values were corrected for multiple comparisons using Benjamini–Hochberg procedure (B–H). Results: Male gender predicted decrease in episodic memory. Poor school marks of practical subjects, having no children, and increase in BMI were associated with decrease in episodic memory, though non-significantly after B–H. Better school marks, and higher occupational class were associated with preserved performance in visual object learning. Higher vocational education predicted preserved performance in visual object learning test, though non-significantly after B-H. Likewise, having children predicted decreased performance in executive functioning but non-significantly after B-H. Conclusions: Adolescent cognitive ability, change in BMI and several sociodemographic factors appear to predict cognitive changes in early midlife. The key advantage of present study is the exploration of possible predictors of change in cognitive performance among general population in the early midlife, a developmental period that has been earlier overlooked
Measuring maternal mortality : an overview of opportunities and options for developing countries
Background:There is currently an unprecedented expressed need and demand for estimates of maternal mortality in developing countries. This has been stimulated in part by the creation of a Millennium Development Goal that will be judged partly on the basis of reductions in maternal mortality by 2015. Methods: Since the launch of the Safe Motherhood Initiative in 1987, new opportunities for data capture have arisen and new methods have been developed, tested and used. This paper provides a pragmatic overview of these methods and the optimal measurement strategies for different developing country contexts. Results: There are significant recent advances in the measurement of maternal mortality, yet also room for further improvement, particularly in assessing the magnitude and direction of biases and their implications for different data uses. Some of the innovations in measurement provide efficient mechanisms for gathering the requisite primary data at a reasonably low cost. No method, however, has zero costs. Investment is needed in measurement strategies for maternal mortality suited to the needs and resources of a country, and which also strengthen the technical capacity to generate and use credible estimates. Conclusion: Ownership of information is necessary for it to be acted upon: what you count is what you do. Difficulties with measurement must not be allowed to discourage efforts to reduce maternal mortality. Countries must be encouraged and enabled to count maternal deaths and act.WJG is funded partially by the University of Aberdeen. OMRC is partially funded by the London School of Hygiene and Tropical Medicine. CS and SA are partially funded by Johns Hopkins University. CAZ is funded by the Health Metrics Network at the World Health Organization. WJG, OMRC, CS and SA are also partially supported through an international research program, Immpact, funded by the Bill & Melinda Gates Foundation, the Department for International Development, the European Commission and USAID
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