Relationship Between Physical Conditioning and Plasma High Density Lipoprotein-Cholesterol Concentration

Five subjects (three females and two males) took part in an exercise regimen in order to determine if aerobic exercise results in an increase in high-density lipoprotein-cholesterol levels (HDL-C) in the plasma. The exercise regimen consisted of running three miles a day, five days per week for six months. Running speed was at such a pace that the subjects attained a minimum of 60% of their maximal heart rate reserve (MHRR). Before the training program began the following parameters were measured in all of the subjects: height, weight, percent body fat, maximal oxygen consumption (Vₒ₂ max), vital capacity, resting heart rate, resting blood pressure, HDL-C, plasma triglycerides (TG), and plasma cholesterol (TC). These same measurements were retaken every two months and at the conclusion of the study. The exercise protocol produced significant changes in Vₒ₂ max and resting heart rate. None of the other parameters were significantly changed. The results of this study have shown that aerobic exercise does not cause significant changes in HDL-C levels

Latent Heat Storage with Phase Change Materials (PCMs)

Latent heat thermal energy storage with phase change materials (PCMs) is attractive since providing a high energy density storage due to the phase change by solidification/melting at constant temperature. Relative to sensible heat energy storage systems, latent heat storage with PCMs requires a smaller weight and volume of material for a given amount of captured/stored energy, and has the capacity to store heat of fusion at a constant or nearly constant temperature, thus maintaining a high and constant temperature difference between the heat exchanging surface and the PCMs.The present review paper will summarize the required properties of PCMs, with their respective advantages and disadvantages; the current state of development and manufacturing; the development of PCM applications, including their incorporation into heat exchangers, insertion of a metal matrix into the PCM, the use of PCM dispersed with high conductivity particles. PCM uses will be illustrated through some case-studies

Some Physiological and Morphological Adaptations for Underwater Survival in Natrix rhombifera and Elaphe obsoleta

The submergence times of the diamondback water snake (Natrix rhombifera) and black rat snake (Elaphe obsoleta) were compared. Both species could easily survive underwater for periods greater than one hour. Furthermore, there was no difference in time of underwater survival in the two species. Some physiological and morphological parameters which may contribute to the ability of N. rhombifera and E. obsoleta to remain submerged were also examined. E. obsoleta was found to have a greater lung volume and larger and more numerous alveoli than N. rhombifera. Both species demonstrated a bradycardia upon submergence but it was less pronounced than the bradycardia of the true diving animals. It is concluded that N. rhombifera has few physiological adaptations for diving and that some of the physiological attributes for an aquatic existence have already developed in E. obsoleta