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21.
M Visser TB Harris J Langlois MT Hannan R Roubenoff DT Felson PW Wilson DP Kiel 《Canadian Metallurgical Quarterly》1998,53(3):M214-M221
BACKGROUND: Low muscle mass has been assumed to be associated with disability, but no studies confirming this association have been published. High body weight and high body mass index, both rough indicators of body fatness, have been shown to increase the risk for disability; however, the specific role of body fatness has not been studied. METHODS: The relations of skeletal muscle mass and percent body fat with self-reported physical disability were studied in 753 men and women aged 72 to 95 years. Cross-sectional data from biennial examination 22 (1992-1993) of the Framingham Heart Study were used. Body composition was assessed by dual-energy x-ray absorptiometry. Disability was scored as any versus none on a 9-item questionnaire. RESULTS: Total body and lower extremity muscle mass were not associated with disability in either men or women. However, a strong positive association between percent body fat and disability was observed. The odds ratio for disability in those in the highest tertile of body fatness was 2.69 (95% confidence interval 1.45-5.00) for women and 3.08 (1.22-7.81) for men compared to those in the lowest tertile. The increased risk could not be explained by age, education, physical activity, smoking, alcohol use, estrogen use (women only), muscle mass, and health status. Analyses restricting disability to mobility items gave similar results. CONCLUSIONS: In contrast to current assumptions, low skeletal muscle mass was not associated with self-reported physical disability. Persons with a high percent body fat had high levels of disability. Because it cannot be ruled out that persons with low skeletal muscle mass dropped out earlier in the study, prospective studies are needed to further assess the relationship between body composition and physical disability. 相似文献
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Madsen Per Jensen Ole Kiel Amtoft Torben Reynisson Ragnar V. Mikkelsen Jan Hvolgaard Laursen SØren Kolding Troels Emil Larsen Torben Jenner Michael Bohl 《Wireless Personal Communications》2002,23(1):55-66
Unified RF requirements are derived for an UMTS Terrestrial RadioAccess/Frequency Division Duplex (UTRA/FDD) compliant mobile transceiver. Aset of transceiver requirements are proposed with consideration to systemissues including duplex aspects. From these design-compatible requirements areproposed for each functional block in the transceiver. 相似文献
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The morphology of synthetic garnierite, Ni3(OH)4. Si2O5, has been studied by electron microscopy. The layer structure of the hollow garnierite needles has been made visible and the observed layer distance is in accordance with the X-ray result. Synthetic garnierite, totally dehydrated above 500° C, appears to be pseudomorphous with garnierite. Total reduction of the dehydrated product in hydrogen yields porous nickel-on-silica in which the small nickel crystallites are only partly accessible to hydrogen chemisorption. 相似文献
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This paper describes an approach for optimizing a key element of air base recovery after attack—the repair of craters on linear taxiway segments. Drawing upon the concept of a minimal cut set, familiar in reliability engineering, an algebraic representation of the problem is developed in the form of a weighted set covering problem. This supplants the use of complex logical algorithms for checking the feasibility of solutions postulated during enumerative solution of the repair minimization problem. It is demonstrated that the algebraic representation leads to enhanced computational efficiency. Also, a potential advantage is suggested for the algebraic approach in facilitating extensions of repair minimization to nonlinear taxiway segments, including intersections.This research was sponsored by the Air Force Contact No. F08635-82-C-0252. 相似文献
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Biodegradable poly(1,4-butanediol succinate) was synthesized from 1,4-butanediol and succinic anhydride. The synthesized polymer was identified by 1H-NMR spectrometer and FT-IR spectrophotometer. The weight average molecular weights were between 4,600 and 29,000, and molecular weight distributions were in the range of 1.7 and 1.9. The glass transition temperature of poly(1,4-butanediol succinate) was revealed at 73°C. The crystallization and cold crystallization of the polymers were investigated as a function of heating rate, cooling rate, reheating rate, and molecular weight. The biodegradation behavior of poly(1,4-butanediol succinate) in micro-organisms such as fungi, actinomycetes, and bacteria was studied by using modified ASTM method. Based upon visual observation, the crystalline structure of films composed of larger molecular weight polymers retained their crystallinity longer than similar structures in low molecular weight samples. © 1995 John Wiley & Sons, Inc. 相似文献
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Kiel Fred; Rimmer Eric; Williams Kathryn; Doyle Marilyn 《Canadian Metallurgical Quarterly》1996,48(2):67
Presents a systems-oriented approach to the leadership development of top-level executives. A structured program is described that is designed to have a positive impact at the organizational level through focused work with the individual client. Leadership effectiveness is seen as strongly influenced by the individual's past, personal life, and work environment. Comprehensive information gathered from the client's work life and personal life increases understanding of behaviors that influence performance, and thereby fosters change. Development is perceived from a holistic point of view, with benefits to the organization accruing through increased effectiveness in any areas of the client's life. A case example (of a 40-yr-old male) is given to illustrate how this approach is put into effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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