Nutritional, Bone, and Physical Fitness States of Jockeys in Chronic Repetition of Short-Term Weight Loss

Professional jockeys are required to fit their weight, mainly weight loss, for two game days every weekend during racing season which usually lasts 10 months a year in Korea. The repetitive routine weight loss protocol is performed for 4 to 5 days a week include two game days. This situation would have brought some negative effects on the professional jockeys\u27 overall health and physical condition with the relation of their performance. The purpose of the present study was: 1) to examine the weight loss habits of pro-jockeys, and 2) effects of chronic short-term weight loss on nutritional status, bone health, and physical fitness of them. Pro jockeys (n=43) completed a questionnaire for the assessment of weight loss habits. Pro jockeys (n=10, around 12 years of career) were compared with trainee jockeys (n=10, less than 1 years of career) for their nutritional status, bone health, and physical fitness. The nutritional status was measured by a computerized program (CAN Pro 2.0). Bone mineral density was measured by DEXA (Hologic, QDR-4500W, USA). All participants performed grip strength test, standing on one leg with eyes closed test, and side step test for the assessment of physical fitness. According to the result, more than 80% of pro jockeys underwent a routine weight loss process every week, for around 1 kg, within 2 to 3 days prior to the game days by diet mainly and/or exercise/sauna. Around 70% of them reported severe fatigue during the weight loss period. There were no significant differences in nutritional status between two groups. However, they consume average of 1,100 Kcal a day reflecting 21 to 80% of recommended daily consumption during weight loss periods. In bone health, six trainee jockeys and two pro jockeys were diagnosed as osteopenia. One pro jockey was diagnosed as osteoporosis. No significant difference was found in fitness factors between two groups. In conclusion, chronic exposure to short-term weight loss may result in serious health problems especially on bone health. For the jockeys in Korea, balanced diet program and the related education on weight management are strongly required.

Dynamic Optical Grating Device and Associated Method for Modulating Light

A dynamic optical grating device and associated method for modulating light is provided that is capable of controlling the spectral properties and propagation of light without moving mechanical components by the use of a dynamic electric and/or magnetic field. By changing the electric field and/or magnetic field, the index of refraction, the extinction coefficient, the transmittivity, and the reflectivity fo the optical grating device may be controlled in order to control the spectral properties of the light reflected or transmitted by the device

Inhibition of Hypoxic Pulmonary Vasoconstriction of Rats by Carbon Monoxide

Hypoxic pulmonary vasoconstriction (HPV), a unique response of pulmonary circulation, is critical to prevent hypoxemia under local hypoventilation. Hypoxic inhibition of K+ channel is known as an important O2-sensing mechanism in HPV. Carbon monoxide (CO) is suggested as a positive regulator of Ca2+-activated K+ channel (BKCa), a stimulator of guanylate cyclase, and an O2-mimetic agent in heme moiety-dependent O2 sensing mechanisms. Here we compared the effects of CO on the HPV (Po2, 3%) in isolated pulmonary artery (HPVPA) and in blood-perfused/ventilated lungs (HPVlung) of rats. A pretreatment with CO (3%) abolished the HPVPA in a reversible manner. The inhibition of HPVPA was completely reversed by 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ), a guanylate cyclase inhibitor. In contrast, the HPVlung was only partly decreased by CO. Moreover, the partial inhibition of HPVlung by CO was affected neither by the pretreatment with ODQ nor by NO synthase inhibitor (L-NAME). The CO-induced inhibitions of HPVPA and HPVlung were commonly unaffected by tetraethylammonium (TEA, 2 mM), a blocker of BKCa. As a whole, CO inhibits HPVPA via activating guanylate cyclase. The inconsistent effects of ODQ on HPVPA and HPVlung suggest that ODQ may lose its sGC inhibitory action when applied to the blood-containing perfusate

Inhibitory Effects of Ambrosia trifida L. on the Development of Root Hairs and Protein Patterns of Radicles

Ambrosia trifida L. is designated as invasive alien species by the Act on the Conservation and Use of Biodiversity by the Ministry of Environment, Korea. The purpose of present paper was to investigate the inhibitory effects of aqueous extracts of A.trifida on the development of root hairs of Triticum aestivum L., and Allium tuberosum Rottler ex Spreng and the electrophoretic protein patterns of their radicles. The development of root hairs was inhibited by increasing of aqueous extract concentrations. Through SDS-PAGE, the electrophoretic protein bands of extracted proteins from their radicles were appeared in controls, but protein bands of specific molecular weight disappeared or weakened in treatments. In conclusion, inhibitory effects of A. trifida made two receptor species changed morphologically, and at the molecular level in early growth stage

High altitude airship configuration and power technology and method for operation of same

A new High Altitude Airship (HAA) capable of various extended applications and mission scenarios utilizing inventive onboard energy harvesting and power distribution systems. The power technology comprises an advanced thermoelectric (ATE) thermal energy conversion system. The high efficiency of multiple stages of ATE materials in a tandem mode, each suited for best performance within a particular temperature range, permits the ATE system to generate a high quantity of harvested energy for the extended mission scenarios. When the figure of merit 5 is considered, the cascaded efficiency of the three-stage ATE system approaches an efficiency greater than 60 percent