Comparison among the critical velocity determined by three conventional models and anaerobic threshold in running

The aim of this study was verify the use of critical velocity (CV) determined by three conventional models for prediction of the anaerobic threshold (AnT) in running. Thirteen Brazilian armed forces soldiers (age 24.6±6.6 years; body mass 74.4±7.6Kg; and body fat 17.8±5.2%) participated of the study. The CV was measured through four different intensities of running accomplished until exhaustion (tlim), it pre-adjusted to occur between 2 and 10 minutes (speed between 15km.h-1 and 21km.h-1). The CV was determined by three mathematical models, two by linear relations (velocity versus inverse of time - VCVx1/tlim; and distance versus time relations - VCDxT) and one by hyperbolic relation (time versus velocity - VCH). The AnT was determined from incremental test on treadmill with initial speed at 7km.h-1 and increment of 1.5km.h-1 at each 3 minutes until voluntary exhaustion. Immediately after each exercise stage were collect blood samples from ear lobe to measure of lactatemia. The AnT corresponded to abrupt increase of the lactate concentration response using bi-segmented linear regression (AnTBI). The three VC determinations corresponded to 13.48±0.91km.h-1 (VCVx1/tlim), 13.04±1.12km.h-1 (VCDxT) and 12.83±0.78km.h-1 (VCH) and only the VCVx1/tlim showed statistically different of the AnTBI (12.06±1.99km.h-1). However, these VC results overestimate the speedy of AnTBI in 11.84±1.30%, 7.7±1.3% and 5.83±1.04%, respectively. Significant correlation was not found among the three VC and the AnTBI. Thus, the CV determined by three conventional models seem not be a good tool for AnT prediction in armed forces soldiers at running

Soil macrofauna in land use systems in Ponta Grossa-Paraná state, Brazil.

Resumo

Multichannel experimental and theoretical constraints for the 116 Cd ( 20 Ne , 20 F ) 116 In charge exchange reaction at 306 MeV

Background: Charge-exchange (CE) reactions offer a major opportunity to excite nuclear isovector modes, providing important clues about the nuclear interaction in the medium. Moreover, double charge-exchange reactions are proving to be a tempting tool to access nuclear transition matrix elements (NMEs) related to double beta-decay processes. The latter are also of crucial importance to extract neutrino properties from the half-life of the hypothetical neutrinoless double beta decay and to search for physics beyond the standard model. Purpose: Through a multichannel experimental analysis and a consistent theoretical approach of the 116 Cd ( 20 Ne , 20 F ) 116 In single charge-exchange (SCE) reaction at 306 MeV, we aim at disentangling from the experimental cross section the contribution of the competing mechanisms associated with second- or higher-order sequential transfer and/or inelastic processes. Methods: We measured excitation energy spectra and absolute cross sections for elastic + inelastic, one-proton transfer and SCE channels by using the MAGNEX large acceptance magnetic spectrometer to detect the ejectiles. For the first two channels, we also extracted the experimental cross-section angular distributions. The experimental data are compared with theoretical predictions obtained by performing two-step distorted-wave Born approximation and coupled reaction channel calculations. We employ spectroscopic amplitudes for single-particle transitions derived within a large-scale shell-model approach and different optical potentials for modeling the initial- and the final-state interactions. Results: The present study significantly mitigates the possible model dependence existing in the description of these complex reaction mechanisms thanks to the satisfactory reproduction of several channels at once. In particular, our work demonstrates that the two-step transfer mechanisms produce a non-negligible contribution to the total cross section of the 116 Cd ( 20 Ne , 20 F ) 116 In reaction channel, although a relevant fraction is still missing, being ascribable to the direct SCE mechanism, which is not addressed here. Conclusions: Our analysis provides a careful estimation of the sequential transfer processes which are competing with the direct SCE mechanism for the heavy ion reaction under investigation. The study suggests that the direct SCE should play an important role among the mechanisms populating the final channel. Nevertheless, the analysis of the higher-order processes considered here is mandatory to isolate the direct SCE process contribution and approach structure information on the corresponding NME from the reaction cross section. The description of the latter process and the competition between the two mechanisms deserves further investigation.Consejo Europeo de Investigación (ERC).Horizonte 2020-714625Ministerio de Economía y Competitividad de España y el Fondo Europeo de Desarrollo Regional (FEDER)-FIS2017-88410-P y FIS2014-53448-C2-1-PDirección General de Asuntos del Personal Académico de la Universidad Nacional Autónoma de México -DGAPA-UNAM IN107820 y AG101120Consejo Nacional de Ciencia y Tecnología de México-CONACyT 314857Fundación de Apoyo a la Investigación del Estado de São Paulo de Brasil-FAPESP. 2019/07767-1Instituto Nacional de Ciência e Tecnologia de Brasil-INCT-FNA 464898/2014-