36 research outputs found
Effects of progressive fatigue and expertise on self-talk content in running: an ambulatory assessment approach
Effects of Progressive Fatigue and Expertise on Self-Talk Content in Running: An Ambulatory Assessment Approach Arne Nieuwenhuys (1)*, Laurens J. Veltman (2), Louise M.A. Braakman-Jansen (2), & Paul A. Davis (3) (1) Behavioural Science Institute, Radboud University Nijmegen, The Netherlands (2) Institute for Behavioral Research, Twente University, The Netherlands (3) Department of Sport Development, Northumbria University, United Kingdom Introduction
In this study we investigated how progressive fatigue differentially affects self-talk use (nr. of statements) and content (instructional, motivational, positive, negative) in recreational and competitive runners, by using a new ambulatory assessment method called âPsyqRunâ â a smartphone application that enables online assessment of psychological states and variables (e.g. self-perceived exertion, self-talk) during exercise. Methods 42 participants (20 recreational runners, 22 competitive runners) performed a strenuous running exercise in which they attempted to reach a maximal distance over eight 2-minute intervals. Self-perceived exertion (RPE) and self-talk were assessed at the end of every interval by using the PsyqRun application. Heart rate was measured continuously with a heart rate monitor. Results RPE scores and heart rate measurement confirmed that fatigue systematically increased as a function of exercise interval. Under high levels of fatigue (i.e., at later intervals) participants generally reported more self-talk statements than under low levels of fatigue (i.e., at earlier intervals). More specifically, with increasing fatigue, participantsâ use of positive and motivational self-talk strongly increased at the cost of instructional self-talk, which strongly decreased. Finally, a marginally significant effect of expertise (p = .058) indicated that competitive runners used more instructional self-talk than recreational runners â also under high levels of fatigue. Discussion Using modern smartphone technology, the current study was the first to provide an online assessment of fatigue and self-talk in running. Findings indicated that participants actively focused on their running technique at the start of the exercise (e.g., âkeep running smoothlyâ) but shifted to self-motivation and perseverance during later intervals, when they became more fatigued (e.g., âjust one more interval!â). These results are consistent with research on fatigue and attentional focus and indicate that â with increasing fatigue â runnersâ thoughts and attention are automatically drawn inwards towards the monitoring of internal states and processes. Finally, it is suggested that by using more instructional self-talk, competitive runners may be able to maintain a more efficient running technique, also under high levels of fatigue. Further development of the PsyqRun application should clarify this matter, by relating the assessment of self-talk to objective measures of running technique and performance
Effect of additives on lithium doped magnesium oxide catalysts used in the oxidative coupling of methane
It has been found that it is possible to improve the activity and stability for the oxidative coupling of methane of a Li/MgO catalyst by the addition of small amounts of the oxides of various transition and rare earth metals. A number of these additives, e.g. SnO2, TiO2, Dy2O3 and Tb4O7, caused little or no difference in the selectivity to C2 products achieved with the resultant catalyst while considerably lowering the temperatures required to give the optimum yields of C2 products. Several other additives caused slight improvements (e.g. La2O3 and NiO) without changing the selectivity and some lowered the temperature for a particular conversion (e.g. CoO, MnO2, PbO and Bi2O3). A number of aspects of some of these catalysts are examined, including the nature of the phases present in the calcined materials, the decomposition of carbonate phases in the catalysts, the effect of promoter concentration and the ageing behaviour under oxidative coupling conditions. A comparison of the various systems shows that the Li/Sn/MgO is an extremely promising catalyst system for the oxidative coupling of methane
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Social Mindfulness and Psychosis: Neural response to socially mindful behavior in first-episode psychosis and patients at clinical high-risk
Background: Psychosis is characterized by problems in social functioning and trust, the assumed glue to positive social relations. But what helps building trust? A prime candidate could be social mindfulness: The ability and willingness to see and consider another personâs needs and wishes during social decision making. We investigated whether first-episode psychosis patients (FEP) and patients at clinical high-risk (CHR) show reduced social mindfulness, and examined the underlying neural mechanisms.
Methods: Twenty FEP, 17 CHR and 46 healthy controls, aged 16-31, performed the social mindfulness task (SoMi) during fMRI scanning, spontaneously and after the instruction âto keep the otherâs best interest in mindâ. As first of two people, participants had to choose one out of four products, of which three were identical and one was unique, differing in a single aspect (e.g., color).
Results: FEP tended to choose the unique item (unmindful choice) more often than controls. After instruction, all groups significantly increased the number of mindful choices compared to the spontaneous condition. FEP showed reduced activation of the caudate and medial prefrontal cortex (mPFC) during mindful, and of the anterior cingulate cortex (ACC), mPFC, and left dorso-lateral prefrontal cortex (dlPFC) during unmindful decisions. CHR showed reduced activation of the ACC compared to controls.
Discussion: FEP showed a trend towards more unmindful choices. A similar increase of mindful choices after instruction indicated the ability for social mindfulness when prompted. Results suggested reduced sensitivity to the rewarding aspects of social mindfulness in FEP, and reduced consideration for the other player. FEP (and CHR to a lesser extent) might perceive unmindful choices as less incongruent with the automatic mindful responses than controls. Reduced socially mindful behavior in FEP may hinder the building of trust and cooperative interactions
Particle decays and stability on the de Sitter universe
We study particle decay in de Sitter space-time as given by first order
perturbation theory in a Lagrangian interacting quantum field theory. We study
in detail the adiabatic limit of the perturbative amplitude and compute the
"phase space" coefficient exactly in the case of two equal particles produced
in the disintegration. We show that for fields with masses above a critical
mass there is no such thing as particle stability, so that decays
forbidden in flat space-time do occur here. The lifetime of such a particle
also turns out to be independent of its velocity when that lifetime is
comparable with de Sitter radius. Particles with mass lower than critical have
a completely different behavior: the masses of their decay products must obey
quantification rules, and their lifetime is zero.Comment: Latex, 38 pages, 1 PostScript figure; added references, minor
corrections and remark
A Constrained Standard Model from a Compact Extra Dimension
A SU(3) \times SU(2) \times U(1) supersymmetric theory is constructed with a
TeV sized extra dimension compactified on the orbifold S^1/(Z_2 \times Z_2').
The compactification breaks supersymmetry leaving a set of zero modes which
correspond precisely to the states of the 1 Higgs doublet standard model.
Supersymmetric Yukawa interactions are localized at orbifold fixed points. The
top quark hypermultiplet radiatively triggers electroweak symmetry breaking,
yielding a Higgs potential which is finite and exponentially insensitive to
physics above the compactification scale. This potential depends on only a
single free parameter, the compactification scale, yielding a Higgs mass
prediction of 127 \pm 8 GeV. The masses of the all superpartners, and the
Kaluza-Klein excitations are also predicted. The lightest supersymmetric
particle is a top squark of mass 197 \pm 20 GeV. The top Kaluza-Klein tower
leads to the \rho parameter having quadratic sensitivity to unknown physics in
the ultraviolet.Comment: 31 pages, Latex, 2 eps figures, minor correction
The Weak Charge of the Proton and New Physics
We address the physics implications of a precision determination of the weak
charge of the proton, QWP, from a parity violating elastic electron proton
scattering experiment to be performed at the Jefferson Laboratory. We present
the Standard Model (SM) expression for QWP including one-loop radiative
corrections, and discuss in detail the theoretical uncertainties and missing
higher order QCD corrections. Owing to a fortuitous cancellation, the value of
QWP is suppressed in the SM, making it a unique place to look for physics
beyond the SM. Examples include extra neutral gauge bosons, supersymmetry, and
leptoquarks. We argue that a QWP measurement will provide an important
complement to both high energy collider experiments and other low energy
electroweak measurements. The anticipated experimental precision requires the
knowledge of the order alpha_s corrections to the pure electroweak box
contributions. We compute these contributions for QWP, as well as for the weak
charges of heavy elements as determined from atomic parity violation.Comment: 22 pages of LaTeX, 5 figure
Z Boson Pair-Production at LEP
Events stemming from the pair-production of Z bosons in e^+e^- collisions are
studied using 217.4 pb^-1 of data collected with the L3 detector at
centre-of-mass energies from 200 GeV up to 209 GeV. The special case of events
with b quarks is also investigated.
Combining these events with those collected at lower centre-of-mass energies,
the Standard Model predictions for the production mechanism are verified. In
addition, limits are set on anomalous couplings of neutral gauge bosons and on
effects of extra space dimensions
Novel genetic loci associated with hippocampal volume
The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness
Study of the W+W-gamma Process and Limits on Anomalous Quartic Gauge Boson Couplings at LEP
The process e+e- -> W+ W- gamma is studied using the data collected by the L3
detector at LEP. New results, corresponding to an integrated luminosity of
427.4 pb-1 at centre-of-mass energies from 192 GeV to 207 GeV, are presented.
The W+W- gamma cross sections are measured to be in agreement with Standard
Model expectations. No hints of anomalous quartic gauge boson couplings are
observed. Limits at 95% confidence level are derived using also the process
e+e- --> nu nubar gamma gamma