Efeito da suplementação de ZMA nos níveis de testosterona em mulheres

O ZMA é um suplemento alimentar que tem em sua composição 30 mg de aspartato de monometionina de zinco, 450 mg de aspartato de magnésio e 10,5 g de vitamina B6. É comercializado com o objetivo de aumentar a produção de pré-hormonais, através da melhora na qualidade do sono e consequentemente na maior liberação dos hormônios Gh e testosterona. O objetivo do presente trabalho foi verificar se a suplementação de ZMA em mulheres sedentárias alteraria os níveis de testosterona e comparar o grupo suplementado com o grupo placebo. Dez participantes do sexo feminino foram divididas em dois grupos (suplementado e placebo) com cinco integrantes cada, o grupo suplementado ingeriu uma cápsula de ZMA antes de dormir durante o período de 4 semanas e o grupo placebo ingeriu uma cápsula placebo antes de dormir durante o mesmo período. Todas as participantes realizaram um exame de sangue antes do primeiro consumo, 14 dias após o início do consumo e ao último dia de consumo das cápsulas com o intuito de mensurar os níveis de testosterona total e testosterona livre. Os resultados dos exames de sangue mostraram que os níveis de testosterona total e testosterona livre não sofreram diferenças significativas comparando-se os grupos suplementado e placebo, analisando cada grupo isoladamente e analisando a evolução nos resultados dos três exames realizados dentro de cada grupo. Assim, conclui-se que esse suplemento não interferiu nos níveis de testosterona total e testosterona livre em mulheres sedentárias. Esse resultado pode ter sido influenciado por variáveis que não foram controladas durante a realização da pesquisa

High-spectral-resolution pulsed photoluminescence study of molecular-beam-epitaxy-grown GaAs/AlxGa1−xAs multi-quantum-well structures using a very-low-power tunable pulsed dye laser

Ultralow-power, high-resolution, pulsed-laser photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies were carried out in molecular-beam-epitaxial GaAs/AlxGa1−xAs multi-quantum-well structures at 5 K. Fine structures were observed for the first time in the PLE spectra, both in the heavy-hole and light-hole excitonic regions. Most of the fine structures are considered to arise from monolayer fluctuations in the thicknesses of the GaAs wells. Dramatic changes in the line shapes and the peak positions of the PL and PLE spectra were observed by applying selective PL detection and excitation spectroscopic techniques

Setting a best practice for determining the EGR rate in hydrogen internal combustion engines

Exhaust gas recirculation (EGR) is an effective way to reduce NOx-emissions and increase the efficiency of hydrogen fueled internal combustion engines. Knowledge of the exact amount of EGR is crucial to understand the effects of EGR. As the exhaust gas flow is pulsating and chemically aggressive, the flow rate is typically not measured directly and has to be derived from other quantities. For hydrocarbon fuels, the EGR rate is generally calculated from a molar CO2 balance, but for hydrogen engines this obviously cannot be used as there are no CO2 emissions, and consequently no standard practice has been established. This work considers three methods to calculate the amount of EGR in a hydrogen engine. The first one is based upon a volume balance in the mixing section of exhaust gases and fresh air. The second and third method uses a molar balance of O-2 and H2O respectively in this mixing section. The three methods are developed and tested for their accuracy with an error analysis. Additionally, the methods are applied to an experimental dataset gathered on a single cylinder hydrogen engine. Both the theoretical analysis and the experimental results confirm the method based on an O-2 molar balance as the most accurate one. The least practical method is the one based on an H2O balance as it requires additional relative humidity sensors and is less accurate than the others

Non-BPS Brane Dynamics And Dual Tensor Gauge Theory

The action for the long wavelength oscillations of a non-BPS p=3 brane embedded in N=1, D=5 superspace is determined by means of the coset method. The D=4 world volume Nambu-Goldstone boson of broken translation invariance and the two D=4 world volume Weyl spinor Goldstinos of the completely broken supersymmetry describe the excitations of the brane into the broken space and superspace directions. The resulting action is an invariant synthesis of the Akulov-Volkov and Nambu-Goto actions. The D=4 antisymmetric tensor gauge theory action dual to the p=3 brane action is determined.Comment: 15 pages, no figure

Quantitative characterization of the Antarctic ozone hole

The long-term evolution of the Antarctic ozone hole is studied based on the TOMS data and the JMA data-set of stratospheric temperature in relation with the possible role of polar stratospheric clouds (PSC's). The effective mass of depleted ozone in the ozone hole at its annual mature stage reached a historical maximum of 55 Mt in 1991, 4.3 times larger than in 1981. The ozone depletion rate during 30 days before the mature ozone hole does not show any appreciable long-term trend but the interannual fluctuations do, ranging from 0.169 to 0.689 Mt/day with the average of 0.419 Mt/day for the period of 1979 - 1991. The depleted ozone mass has the highest correlation with the region below 195 K on the 30 mb surface in June, whereas the ozone depletion rate correlates most strongly with that in August. The present result strongly suggests that the long-term evolution of the mature ozone hole is caused both by the interannual change of the latitudinal coverage of the early PSC's, which may control the latitude and date of initiation of ozone decrease, and by that of the spatial coverage of the mature PSC's which may control the ozone depletion rate in the Antarctic spring

Non-Abelian Walls in Supersymmetric Gauge Theories

The Bogomol'nyi-Prasad-Sommerfield (BPS) multi-wall solutions are constructed in supersymmetric U(N_C) gauge theories in five dimensions with N_F(>N_C) hypermultiplets in the fundamental representation. Exact solutions are obtained with full generic moduli for infinite gauge coupling and with partial moduli for finite gauge coupling. The generic wall solutions require nontrivial configurations for either gauge fields or off-diagonal components of adjoint scalars depending on the gauge. Effective theories of moduli fields are constructed as world-volume gauge theories. Nambu-Goldstone and quasi-Nambu-Goldstone scalars are distinguished and worked out. Total moduli space of the BPS non-Abelian walls including all topological sectors is found to be the complex Grassmann manifold SU(N_F) / [SU(N_C) x SU(N_F-N_C) x U(1)] endowed with a deformed metric.Comment: 62 pages, 17 figures, the final version in PR

Global Structure of Moduli Space for BPS Walls

We study the global structure of the moduli space of BPS walls in the Higgs branch of supersymmetric theories with eight supercharges. We examine the structure in the neighborhood of a special Lagrangian submanifold M, and find that the dimension of the moduli space can be larger than that naively suggested by the index theorem, contrary to previous examples of BPS solitons. We investigate BPS wall solutions in an explicit example of M using Abelian gauge theory. Its Higgs branch turns out to contain several special Lagrangian submanifolds including M. We show that the total moduli space of BPS walls is the union of these submanifolds. We also find interesting dynamics between BPS walls as a byproduct of the analysis. Namely, mutual repulsion and attraction between BPS walls sometimes forbid a movement of a wall and lock it in a certain position; we also find that a pair of walls can transmute to another pair of walls with different tension after they pass through.Comment: 42 pages, 11 figures; a few comments adde

Homodyne detection for measuring internal quantum correlations of optical pulses

A new method is described for determining the quantum correlations at different times in optical pulses by using balanced homodyne detection. The signal pulse and sequences of ultrashort test pulses are superimposed, where for chosen distances between the test pulses their relative phases and intensities are varied from measurement to measurement. The correlation statistics of the signal pulse is obtained from the time-integrated difference photocurrents measured.Comment: 7 pages, A4.sty include