24 research outputs found
A one-dimensional lattice model for a quantum mechanical free particle
Two types of particles, A and B with their corresponding antiparticles, are
defined in a one dimensional cyclic lattice with an odd number of sites. In
each step of time evolution, each particle acts as a source for the
polarization field of the other type of particle with nonlocal action but with
an effect decreasing with the distance: A -->...\bar{B} B \bar{B} B \bar{B} ...
; B --> A \bar{A} A \bar{A} A ... . It is shown that the combined distribution
of these particles obeys the time evolution of a free particle as given by
quantum mechanics.Comment: 8 pages. Revte
Fotossíntese, reservas orgânicas e rebrota do capim-mombaça (Panicum maximum Jacq.)sob diferentes intensidades de desfolha do perfilho principal
Sophora tomentosa e Crotalaria vitellina (Fabaceae): biologia reprodutiva e interações com abelhas na restinga de Ubatuba, São Paulo
Skeletal Muscle Adaptive Responses to Different Types of Short-Term Exercise Training and Detraining in Middle-Age Men
Introduction
Whether short-term, single-mode exercise training can improve physical fitness prior to a period of reduced physical activity (e.g. post-surgery recovery) is not well characterized in clinical populations nor middle-age adults. We investigated skeletal muscle adaptive responses following endurance exercise training (ENT), high-intensity interval training (HIIT) or resistance exercise training (RET), and a subsequent period of detraining, in sedentary, middle-age men.
Methods
Thirty-five sedentary, males (39±3 yr) were randomized to parallel groups and undertook six weeks of either ENT (n=12), HIIT (n=12) or RET (n=11) followed by 2.5 weeks of detraining. Skeletal muscle fiber characteristics, body composition, muscle thickness, muscle strength, aerobic capacity, resting energy expenditure and glucose homeostasis were assessed at baseline, and after exercise training and detraining.
Results
Lean mass increased after RET and HIIT (+3.2±1.6% and +1.6±2.1%, P<0.05). Muscle strength (sum of leg press, leg extension and bench press 1RMs) increased after all training interventions (RET: +25±5%; HIIT: +10±5%; ENT: +7±7%, P<0.05). Aerobic capacity increased only after HIIT and ENT (+14±7% and +11±11%, P<0.05). Type I and II muscle fiber size increased for all groups post-training (main effect of time, P<0.05). Following a period of detraining, the gains in lean mass and maximal muscle strength were maintained in RET and HIIT groups, but maximal aerobic capacity declined below post-training levels in HIIT and ENT (P<0.05).
Conclusion
Six weeks of HIIT induced widespread adaptations prior to detraining in middle-age men. Exercise training-induced increases in aerobic capacity declined during 2.5 weeks of detraining but gains in lean mass and muscle strength were maintained
Controversies in omega-3 efficacy and novel concepts for application
Interest in the cardioprotective effects of long chain omega-3 polyunsaturated fatty acids (LCn3) was largely influenced by the low rates of cardiovascular disease (CVD) amongst the Inuits of Greenland who consumed a high marine fat diet rich in LCn3s. This finding stimulated years of epidemiological and clinical studies investigating the cardioprotective effects of LCn3s, thought to be primarily mediated through anti-inflammatory (and anti-aggregatory) prostaglandins that protect the vascular wall from pro-inflammatory effects of metabolic stress precipitated by poor diet and lifestyle. Although the original hypothesis of the link between LCn3s and CVD protection was based on a high LCn3 containing diet (namely a high marine fat diet) the majority of clinical trials since have focussed on EPA and DHA supplementation, and results of repeated meta-analyses have not shown conclusive evidence in support of their beneficial health effects. In this review we focus on the controversies that surround the efficacy of LCn3s in cardiovascular and other chronic diseases and present emerging areas of research for novel applications. We will examine factors that can impact on the efficacy of LCn3s such as source (plant vs marine vs supplements (algal vs marine)), stability of product, dose, trial duration, ratio of EPA:DHA, and ratio of LCn6:LCn3 fatty acids in the diet