1,031 research outputs found
Perfectionism, achievement motives, and attribution of success and failure in female soccer players
While some researchers have identified adaptive perfectionism as a key characteristic to achieving elite performance in sport, others see perfectionism as a maladaptive characteristic that undermines, rather than helps, athletic performance. Arguing that perfectionism in sport contains both adaptive and maladaptive facets, the present article presents a study of N 5 74 female soccer players investigating how two facets of perfectionism—perfectionistic strivings and negative reactions to imperfection (Stoeber, Otto, Pescheck, Becker, & Stoll, 2007)—are related to achievement motives and attributions of success and failure. Results show that striving for perfection was related to hope of success and self-serving attributions (internal attribution of success). Moreover, once overlap between the two facets of perfectionism was controlled for, striving for perfection was inversely related to fear of failure and self-depreciating attributions (internal attribution of failure). In contrast,
negative reactions to imperfection were positively related to fear of failure and self-depreciating attributions (external attribution of success) and inversely related to self-serving attributions (internal attribution of success and external attribution of failure). It is concluded that striving for perfection in sport is associated with an adaptive pattern of positive motivational orientations and self-serving attributions of success and failure, which
may help athletic performance. In contrast, negative reactions to imperfection are associated with a maladaptive
pattern of negative motivational orientations and self-depreciating attributions, which is likely to undermine athletic performance. Consequently, perfectionism in sport may be adaptive in those athletes who strive for perfection, but can control their negative reactions when performance is less than perfect
Measuring the photon distribution by ON/OFF photodectors
Reconstruction of photon statistics of optical states provide fundamental
information on the nature of any optical field and find various relevant
applications. Nevertheless, no detector that can reliably discriminate the
number of incident photons is available. On the other hand the alternative of
reconstructing density matrix by quantum tomography leads to various technical
difficulties that are particular severe in the pulsed regime (where mode
matching between signal an local oscillator is very challenging). Even if
on/off detectors, as usual avalanche PhotoDiodes operating in Geiger mode, seem
useless as photocounters, recently it was shown how reconstruction of photon
statistics is possible by considering a variable quantum efficiency. Here we
present experimental reconstructions of photon number distributions of both
continuous-wave and pulsed light beams in a scheme based on on/off avalanche
photodetection assisted by maximum-likelihood estimation. Reconstructions of
the distribution for both semiclassical and quantum states of light (as single
photon, coherent, pseudothermal and multithermal states) are reported for
single-mode as well as for multimode beams. The stability and good accuracy
obtained in the reconstruction of these states clearly demonstrate the
interesting potentialities of this simple technique.Comment: 6 pages, 7 figures, to appear on Laser Physic
Universal homodyne tomography with a single local oscillator
We propose a general method for measuring an arbitrary observable of a
multimode electromagnetic field using homodyne detection with a single local
oscillator. In this method the local oscillator scans over all possible linear
combinations of the modes. The case of two modes is analyzed in detail and the
feasibility of the measurement is studied on the basis of Monte-Carlo
simulations. We also provide an application of this method in tomographic
testing of the GHZ state.Comment: 12 pages, 5 figures (8 eps files
Bitwise Bell inequality violations for an entangled state involving 2N ions
Following on from previous work [J. A. Larsson, Phys. Rev. A 67, 022108
(2003)], Bell inequalities based on correlations between binary digits are
considered for a particular entangled state involving 2N trapped ions. These
inequalities involve applying displacement operations to half of the ions and
then measuring correlations between pairs of corresponding bits in the binary
representations of the number of centre-of-mass phonons of N particular ions.
It is shown that the state violates the inequalities and thus displays
nonclassical correlations. It is also demonstrated that it violates a Bell
inequality when the displacements are replaced by squeezing operations.Comment: 12 pages, 5 figures, accepted for publication in Phys. Rev.
Indentation-induced damage in GaN epilayers
The mechanical deformation of wurtzite GaN epilayers grown on sapphire substrates is studied by spherical indentation, cross-sectional transmission electron microscopy (XTEM), and scanning cathodoluminescence(CL) monochromatic imaging. CL imaging of indents which exhibit plastic deformation (based on indentation data) shows an observable “footprint” of deformation-produced defects that result in a strong reduction in the intensity of CL emission. Multiple discontinuities are observed during loading when the maximum load is above the elastic-plastic threshold, and such a behavior can be correlated with multiple slip bands revealed by XTEM. No evidence of pressure-induced phase transformations is found from within the mechanically damaged regions using selected-area diffraction patterns. The main deformation mechanism appears to be the nucleation of slip on the basal planes, with dislocations being nucleated on additional planes on further loading. XTEM reveals no cracking or delamination in any of the samples studied for loads of up to 250 mN
Gaussian Wigner distributions and hierarchies of nonclassical states in quantum optics-The single mode case
A recently introduced hierarchy of states of a single mode quantised
radiation field is examined for the case of centered Guassian Wigner
distributions. It is found that the onset of squeezing among such states
signals the transition to the strongly nonclassical regime. Interesting
consequences for the photon number distribution, and explicit representations
for them, are presented.Comment: 11 Pages Revtex one eps figure. Replaced with minor changes in ref
Polymorphisms in the WNK1 gene are asociated with blood pressure variation and urinary potassium excretion
WNK1 - a serine/threonine kinase involved in electrolyte homeostasis and blood pressure (BP) control - is an excellent candidate gene for essential hypertension (EH). We and others have previously reported association between WNK1 and BP variation. Using tag SNPs (tSNPs) that capture 100% of common WNK1 variation in HapMap, we aimed to replicate our findings with BP and to test for association with phenotypes relating to WNK1 function in the British Genetics of Hypertension (BRIGHT) study case-control resource (1700 hypertensive cases and 1700 normotensive controls). We found multiple variants to be associated with systolic blood pressure, SBP (7/28 tSNPs min-p = 0.0005), diastolic blood pressure, DBP (7/28 tSNPs min-p = 0.002) and 24 hour urinary potassium excretion (10/28 tSNPs min-p = 0.0004). Associations with SBP and urine potassium remained significant after correction for multiple testing (p = 0.02 and p = 0.01 respectively). The major allele (A) of rs765250, located in intron 1, demonstrated the strongest evidence for association with SBP, effect size 3.14 mmHg (95%CI:1.23–4.9), DBP 1.9 mmHg (95%CI:0.7–3.2) and hypertension, odds ratio (OR: 1.3 [95%CI: 1.0–1.7]).We genotyped this variant in six independent populations (n = 14,451) and replicated the association between rs765250 and SBP in a meta-analysis (p = 7×10−3, combined with BRIGHT data-set p = 2×10−4, n = 17,851). The associations of WNK1 with DBP and EH were not confirmed. Haplotype analysis revealed striking associations with hypertension and BP variation (global permutation p10 mmHg reduction) and risk for hypertension (OR<0.60). Our data indicates that multiple rare and common WNK1 variants contribute to BP variation and hypertension, and provide compelling evidence to initiate further genetic and functional studies to explore the role of WNK1 in BP regulation and EH
The role of GRIP1 and ephrin B3 in blood pressure control and vascular smooth muscle cell contractility
This work was supported by grants from the Canadian Institutes of Health Research to J.W. (MOP57697,
MOP69089 and MOP 123389), H.L. (MOP97829), and G.C. (CMI72323). It was also financed by grants from
the Natural Sciences and Engineering Research Council of Canada (203906-2012), and the J.-Louis Levesque
Foundation to J.W. This study was also made possible by a group grant from the National Sciences Foundation of
China (#81361120264) to J.S., S.H. T.W. and J.W. The funders provided support in the form of salaries for authors
[Y.W.; Z.W.; H.L.; J.P.; J.R.], and experimental costs, but did not have any additional role in the study design, data
collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors
are articulated in the “author contributions”. The authors thank Regeneron Pharmaceuticals for generously
providing Efnb3 KO mice. The authors thank all the authors of the International Consortium for Blood Pressure
Genome-Wide Association Studies for allow us to mine the study dataset
Number phase uncertainty relations: verification by homodyning
It is shown that fundamental uncertainty relations between photon number and
canonical phase of a single-mode optical field can be verified by means of
balanced homodyne measurement. All the relevant quantities can be sampled
directly from the measured phase-dependent quadrature distribution.Comment: 1 Ps figure (divided in 3 subfigures) using REVTE
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