Athletic Nutrition

Science has broken down many of the barriers that once kept athletes from performing at their very best. This has been done through the scientific study of athletes and the development of a combination of proper training, technique, mental attitude, and nutrition. While training and technique are variables that come with time and practice, proper nutrition can produce positive changes in an athlete\u27s performance in a relatively short period of time. Eating the right kinds of foods, in the right proportions, for a given type of athletic event (Le. aerobic, anaerobic, strength, and muscular definition) can provide an athlete the boost he or she needs to get to the next level of performance. Athletic nutrition has been looked at as a Cookbook process in which the goals of the individual are overlooked or disregarded. Some clinical nutritionists believe that the Recommended Daily Allowance still covers the athletes\u27 daily nutritional requirements. The need for increased amounts of all nutrients are not seen to be necessary, despite the differing demands of occupation or increased demands of training for athletes. Yet, science has proven this to be wrong. Studies have shown that the nutritional needs of the working man and woman, not to mention athletes, are not satisfied by the Recommended Daily Allowance. The idea that the Recommended Daily Allowance is adequate for athletes has been perpetuated by big business and some health and sports organizations for many years. The purpose of this literature review is to compile information that is currently available and provide a resource manual for clinicians. This review will discuss nutrient requirements for protein, carbohydrates, fats, vitamins, minerals, and water. The review will go further and discuss the role that supplements and sleep play in the athlete\u27s diet

Spin-Glass-like Transition and Hall Resistivity of Y2-xBixIr2O7

Various physical properties of the pyrochlore oxide Y2-xBixIr2O7 have been studied. The magnetizations M measured under the conditions of the zero-field-cooling(ZFC) and the field-cooling(FC) have different values below the temperature T=TG. The anomalous T-dependence of the electrical resistivities r and the thermoelectric powers S observed at around TG indicates that the behavior of the magnetization is due to the transition to the state with the spin freezing. In this spin-frozen state, the Hall resistivities rH measured with the ZFC and FC conditions are found to have different values, too, in the low temperature phase (T<TG). Possible mechanisms which induce such the hysteretic behavior are discussed.Comment: 9 pages, 7 figures, J. Phys. Soc. Jpn. 72 (2003) No.

Color-Pattern Evolution in Response to Environmental Stress in Butterflies

It is generally accepted that butterfly wing color-patterns have ecological and behavioral functions that evolved through natural selection. However, particular wing color-patterns may be produced physiologically in response to environmental stress, and they may lack significant function. These patterns would represent an extreme expression of phenotypic plasticity and can eventually be fixed genetically in a population. Here, three such cases in butterflies are concisely reviewed, and their possible mechanisms of genetic assimilation are discussed. First, a certain modified color-pattern of Vanessa indica induced by temperature treatments resembles the natural color-patterns of its closely related species of the genus Vanessa (sensu stricto). Second, a different type of color-pattern modification can be induced in Vanessa cardui as a result of a general stress response. This modified pattern is very similar to the natural color-pattern of its sister species Vanessa kershawi. Third, a field observation was reported, together with experimental support, to show that the color-pattern diversity of a regional population of Zizeeria maha increased at the northern range margin of this species in response to temperature stress. In these three cases, modified color-patterns are unlikely to have significant functions, and these cases suggest that phenotypic plasticity plays an important role in butterfly wing color-pattern evolution. A neutral or non-functional trait can be assimilated genetically if it is linked, like a parasitic trait, with another functional trait. In addition, it is possible that environmental stress causes epigenetic modifications of genes related to color-patterns and that their transgenerational inheritance facilitates the process of genetic assimilation of a neutral or non-functional trait

Flux-free conductance modulation in a helical Aharonov-Bohm interferometer

A novel conductance oscillation in a twisted quantum ring composed of a helical atomic configuration is theoretically predicted. Internal torsion of the ring is found to cause a quantum phase shift in the wavefunction that describes the electron's motion along the ring. The resulting conductance oscillation is free from magnetic flux penetrating inside the ring, which is in complete contrast with the ordinary Aharonov-Bohm effect observed in untwisted quantum rings.Comment: 10 pages, 4 figure