5,285 research outputs found
Replacement of dietary saturated fatty acids by trans fatty acids lowers serum HDL cholesterol and impairs endothelial function in healthy men and women
We tested whether trans fatty acids and saturated fatty acids had different effects on flow-mediated vasodilation (FMD), a risk marker of coronary heart disease (CHD). Consumption of trans fatty acids is related to increased risk of CHD, probably through effects on lipoproteins. Trans fatty acids differ from most saturated fatty acids because they decrease serum high-density lipoprotein (HDL) cholesterol, and this may increase the risk of CHD. We fed 29 volunteers 2 controlled diets in a 2x4-week randomized crossover design. The "Trans-diet" contained 9.2 energy percent of trans fatty acids; these were replaced by saturated fatty acids in the "Sat-diet." Mean serum HDL cholesterol after the Trans-diet was 0.39 mmol/L (14.8 mg/dL), or 21␕ower than after the Sat-diet (95␌I 0.28 to 0.50 mmol/L). Serum low density lipoprotein and triglyceride concentrations were stable. FMD SD was 4.4±2.3fter the Trans-diet and 6.2±3.0fter the Sat-diet (difference -1.8°95␌I -3.2 to -0.4). Replacement of dietary saturated fatty acids by trans fatty acids impaired FMD of the brachial artery, which suggests increased risk of CHD. Further studies are needed to test whether the decrease in serum HDL cholesterol caused the impairment of FMD
1986-89
Reflecting upon the Caucus is for me a bit like reflecting upon an event like giving birth. Your work/body is taken over by larger forces. Your biography divides itself into pre and post. You can never again be who you were. And yet what is the Caucus on Social Theory? What\u27s to be learned about it from that short period of history during which I worked as Coordinator {1986-89}
Dynamics of a Classical Particle in a Quasi Periodic Potential
We study the dynamics of a one-dimensional classical particle in a space and
time dependent potential with randomly chosen parameters. The focus of this
work is a quasi-periodic potential, which only includes a finite number of
Fourier components. The momentum is calculated analytically for short time
within a self-consistent approximation, under certain conditions.
We find that the dynamics can be described by a model of a random walk
between the Chirikov resonances, which are resonances between the particle
momentum and the Fourier components of the potential. We use numerical methods
to test these results and to evaluate the important properties, such as the
characteristic hopping time between the resonances. This work sheds light on
the short time dynamics induced by potentials which are relevant for optics and
atom optics
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Fool\u27s Gold: Comparing Two Political and Economic Crises in Brazilian History
This paper’s goal is to compare and contrast the political and economic crisis that affected the Brazilian military dictatorship from the late 1970’s to mid 1980’s to the political and economic crisis currently affecting Brazil in order to get a better idea of what may be the political effects of the current crisis. This paper argues that both the current crisis and the one under the dictatorship stem from similar causes. It also argues that Brazilian democracy, much like the military dictatorship before it, risks being fatally undermined politically by an economic crisis it is responsible for
Analysis of a single-mode waveguide at sub-terahertz frequencies as a communication channel
We study experimentally the transmission of an electromagnetic waveguide in the frequency range from 160 to 300 GHz. Photo-mixing is used to excite and detect the fundamental TE10 mode in a rectangular waveguide with two orders-of-magnitude lower impedance. The large impedance mismatch leads to a strong frequency dependence of the transmission, which we measure with a high-dynamic range of up to 80 dB and with high frequency-resolution. The modified transmission function is directly related to the information rate of the waveguide, which we estimate to be about 1 bit per photon. We suggest that the results are applicable to a Josephson junction employed as a single-photon source and coupled to a superconducting waveguide to achieve a simple on-demand narrow-bandwidth free-space number-state quantum channel
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