L’objectif était d’examiner la relation entre la perception de l’effort (RPE) au seuil d’oxydation maximale des lipides (LIPOXmax), les réponses physiologiques et le profil psychologique des ...cyclistes entraînés.
Vingt et un cyclistes compétiteurs réalisaient un test afin de déterminer leur RPE au LIPOXmax. Durant ce test, les réponses physiologiques au LIPOXmax étaient relevées. De plus, le profil psychologique de chaque cycliste a été évalué par questionnaires (anxiété, désir de réussite, estime de soi, endurance et résistance psychologiques, vitesse-dynamisme, compétitivité, contrôle de l’activité, prise de risque, contrôle émotionnel, extraversion–introversion, dominance, agressivité, sociabilité, coopération, acquiescence et désirabilité sociale). Une analyse de régression linéaire multiple était réalisée pour déterminer les facteurs physiologiques et psychologiques liés à la RPE au LIPOXmax.
Seuls le pourcentage de la consommation maximale d’oxygène (V˙O2max), la dominance et l’endurance psychologique contribuaient à expliquer significativement la RPE au LIPOXmax.
Plus les cyclistes ont une RPE au LIPOXmax basse, plus leur LIPOXmax (en %V˙O2max) est faible. De plus, les cyclistes dominants (i.e., persuasifs, ayant des aptitudes au commandement) et/ou endurants psychologiquement (i.e., persévérants, déterminés, obstinés) ont une RPE au LIPOXmax plus faible que les cyclistes moins dominants et/ou moins endurants psychologiquement.
The objective was to examine the relationship between rating of perceived exertion (RPE) at the point of maximal lipids oxidation (LIPOXmax), physiological responses and psychological profile in trained competitive cyclists.
Twenty-one competitive cyclists performed an exercise test in order to determine RPE at LIPOXmax. During this exercise test, physiological responses at LIPOXmax were measured. Moreover, a psychological profile for each cyclist has been evaluated from questionnaires (levels of anxiety, desire for success, self-esteem, psychological resistance and endurance, dynamism, competitiveness, activity control, risk-taking, emotional control, extroversion–introversion, leadership, aggressiveness, sociability, cooperation, acceptance of a judgment, and social desirability). Multiple linear regression analysis was performed to determine the physiological and psychological factors linked to RPE at LIPOXmax.
Only the percentage of maximal oxygen uptake (%V˙O2max), leadership and psychological endurance explained significantly the RPE at LIPOXmax.
More the cyclists have a low RPE at LIPOXmax, more their LIPOXmax (in V˙O2max) was low. Cyclists with high level of leadership (i.e., persuasive, with command ability) and/or psychological endurance (i.e., persistent, obstinate) have lower RPE at LIPOXmax than the cyclists with lower level of leadership and/or psychological endurance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract
The solenoidal large intensity device (SoLID) is a new experimental apparatus planned for Hall A at the Thomas Jefferson National Accelerator Facility (JLab). SoLID will combine large ...angular and momentum acceptance with the capability to handle very high data rates at high luminosity. With a slate of approved high-impact physics experiments, SoLID will push JLab to a new limit at the QCD intensity frontier that will exploit the full potential of its 12 GeV electron beam. In this paper, we present an overview of the rich physics program that can be realized with SoLID, which encompasses the tomography of the nucleon in 3D momentum space from semi-inclusive deep inelastic scattering, expanding the phase space in the search for new physics and novel hadronic effects in parity-violating DIS, a precision measurement of
J
/
ψ
production at threshold that probes the gluon field and its contribution to the proton mass, tomography of the nucleon in combined coordinate and momentum space with deep exclusive reactions, and more. To meet the challenging requirements, the design of SoLID described here takes full advantage of recent progress in detector, data acquisition and computing technologies. In addition, we outline potential experiments beyond the currently approved program and discuss the physics that could be explored should upgrades of CEBAF become a reality in the future.
Les objectifs étaient d’examiner l’influence du niveau de performance sur le point d’oxydation maximale des lipides (Lipox
max) chez des cyclistes, et d’identifier les zones d’intensités cibles ...correspondantes au Lipox
max.
Vingt-quatre cyclistes entraînés étaient répartis en deux groupes en fonction de leur niveau de performance en cyclisme (G1: 17 cyclistes de niveau départemental à régional versus G2: sept cyclistes élites ou professionnels). Tous les cyclistes (G1 et G2) réalisaient un même test de calorimétrie d’effort, durant lequel les paramètres cardiorespiratoires et la perception de l’effort (RPE) étaient mesurés. Le Lipox
max était identifié, puis exprimé sous la forme d’un pourcentage de la puissance maximale aérobie (PMA), de la consommation maximale d’oxygène (
V
˙
O
2
max
), de la consommation d’oxygène de réserve (
V
˙
O
2
r
é
serve
), de la fréquence cardiaque maximale (FC
max), de la fréquence cardiaque de réserve (FC
réserve) et à une valeur de RPE. Ces valeurs étaient ensuite comparées par une Anova à une voie (G1 versus G2).
Les intervalles de confiance à 95 % (IC95 %) du Lipox
max correspondait à 37–44 % PMA, 41–47 %
V
˙
O
2
max
, 35–42 %
V
˙
O
2
r
é
serve
, 44–59 % FC
réserve et à RPE 8–10, indépendant du groupe (
p
>
0,05). Toutefois, un effet groupe était noté lorsque le Lipox
max était exprimé en pourcentage de la FC
max (IC95 %
=
56–61 % et 60–70 % FC
max pour G1 et G2, respectivement;
p
=
0,03). Cependant, une large dispersion des valeurs de Lipox
max était constatée.
Chez ces cyclistes, le niveau de performance n’influence pas le Lipox
max (sauf lorsque ce dernier est exprimé en % FC
max). Il semble toutefois difficile d’utiliser des intensités cibles communes pour prescrire l’intensité d’exercice au Lipox
max chez ces cyclistes.
The main objectives of this study were: (1) to test the effect of performance level on the maximum lipids oxidation flow rate (LIPOX
max) in trained cyclists, and (2) to identify the target exercise intensities corresponding to LIPOX
max.
Twenty-four trained cyclists were distributed in two groups according to their performance level (G1: 17 cyclists with local level versus G2: seven cyclists with elite level). All cyclists performed the same exercise test. Cardiorespiratory data and rating of perceived exertion (RPE) were measured during each stage. LIPOX
max was determined, and then expressed in terms of percentage of maximal aerobic power (MAP), maximal oxygen uptake (
V
˙
O
2
max
), reserve oxygen uptake (
V
˙
O
2
r
é
serve
), maximal heart rate (HR
max), reserve heart rate (HR
reserve), and RPE. These values were compared from one-way ANOVA (G1 versus G2).
Confidence intervals (CI95%) of LIPOX
max corresponded to 37–44% MAP, 41–47%
V
˙
O
2
max
, 35–42%
V
˙
O
2
r
é
serve
, 44–59% HR
reserve, and to RPE 8–10, independently of group (
p
>
0.05). However, group effect was noticed when LIPOX
max was expressed in terms of HR
max (CI95%
=
56–61% and 60–70% HR
max for G1 and G2, respectively;
p
=
0.03). However, a large part of the interindividual variation of LIPOX
max was noticed.
The performance level do not influence the LIPOX
max in trained cyclists (except if it is expressed in % HR
max). It seems difficult to use common target exercise intensities in order to prescribe exercise intensity corresponding to LIPOX
max in trained cyclists.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Metastasis is responsible for most deaths due to malignant melanoma. The clinical significance of micrometastases in the lymph is a hotly debated topic, but an improved understanding of the lymphatic ...spread of cancer remains important for improving cancer survival. Cellular magnetic resonance imaging (MRI) is a newly emerging field of imaging research that is expected to have a large impact on cancer research. In this study, we demonstrate the cellular MRI technology required to reliably image the lymphatic system in mice and to detect iron-labeled metastatic melanoma cells within the mouse lymph nodes. Melanoma cells were implanted directly into the inguinal lymph nodes in mice, and micro-MRI was performed using a customized 1.5-T clinical MRI system. We show cell detection of as few as 100 iron-labeled cells within the lymph node, with injections of larger cell numbers producing increasingly obvious regions of signal void. In addition, we show that cellular MRI allows monitoring of the fate of these cells over time as they develop into intranodal tumors. This technology will allow noninvasive investigations of cellular events in cancer metastasis within an entire animal and will facilitate progress in understanding the mechanisms of metastasis within the lymphatic system.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The E12-14-012 experiment, performed in Jefferson Lab Hall A, has measured the $(e, e'p)$ cross section in parallel kinematics using a natural argon target. Here, we report the full results of the ...analysis of the data set corresponding to beam energy 2.222 GeV, and spanning the missing momentum and missing energy range $15 \lesssim p_m \lesssim 300$ MeV/c and $12 \lesssim E_m \lesssim 80$ MeV. The reduced cross section, determined as a function of $p_m$ and $E_m$ with $\approx$4\% accuracy, has been fitted using the results of Monte Carlo simulations involving a model spectral function and including the effects of final state interactions. The overall agreement between data and simulations turns out to be quite satisfactory ($\chi^2$/n.d.o.f.=1.9). Furthermore, the resulting spectral function will provide valuable new information, needed for the interpretation of neutrino interactions in liquid argon detectors.
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We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q^{2}) up to 15.75 (GeV/c)^{2}. Combined with existing data, these provide an ...improved extraction of the proton magnetic form factor at high Q^{2} and double the range over which a longitudinal or transverse separation of the cross section can be performed. The difference between our results and polarization data agrees with that observed at lower Q^{2} and attributed to hard two-photon exchange (TPE) effects, extending to 8 (GeV/c)^{2} the range of Q^{2} for which a discrepancy is established at >95% confidence. We use the discrepancy to quantify the size of TPE contributions needed to explain the cross section at high Q^{2}.
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To probe CP violation in the leptonic sector using GeV energy neutrino beams in current and future experiments using argon detectors, precise models of the complex underlying neutrino and ...antineutrino interactions are needed. The E12-14-012 experiment at Jefferson Lab Hall A was designed to perform a combined analysis of inclusive and exclusive electron scatterings on both argon (N = 22) and titanium (Z = 22) nuclei using GeV-energy electron beams. The measurement on titanium nucleus provides essential information to understand the neutrino scattering on argon, large contribution to which comes from scattering off neutrons. Here we report the first experimental study of electron-titanium scattering as double-differential cross section at beam energy E = 2.222 GeV and electron-scattering angle theta = 15.541 degrees, measured over a broad range of energy transfer, spanning the kinematical regions in which quasielastic scattering and delta production are the dominant reaction mechanisms. The data provide valuable new information needed to develop accurate theoretical models of the electromagnetic and weak cross sections of these complex nuclei in the kinematic regime of interest to neutrino experiments.
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A system of modular sealed gas target cells has been developed for use in electron scattering experiments at the Thomas Jefferson National Accelerator Facility (Jefferson Lab). This system was ...initially developed to complete the MARATHON experiment which required, among other species, tritium as a target material. Thus far, the cells have been loaded with the gas species 3H, 3He, 2H, 1H and 40Ar and operated in nominal beam currents of up to 22.5 μA in Jefferson Lab’s Hall A. While the gas density of the cells at the time of loading is known, the density of each gas varies uniquely when heated by the electron beam. To extract experimental cross sections using these cells, density dependence on beam current of each target fluid must be determined. In this study, data from measurements with several beam currents within the range of 2.5 to 22.5 μA on each target fluid are presented. Additionally, expressions for the beam current dependent fluid density of each target are developed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The E12-14-012 experiment, performed in Jefferson Lab Hall A, has measured the (e, e'p) cross section in parallel kinematics using a natural titanium target. In this paper, we report the analysis of ...the dataset obtained in different kinematics for our solid natural titanium target. Data were obtained in a range of missing momentum and missing energy between 15 ≲ pm ≲ 250 MeV / c and 12 ≲ Em ≲ 80 MeV, respectively, and using an electron beam energy of 2.2 GeV. We measured the reduced cross section with ~7% accuracy as a function of both missing momentum and missing energy. Furthermore, our Monte Carlo simulation, including both a model spectral function and the effects of final-state interactions, satisfactorily reproduces the data.
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