43,439 research outputs found
The relationship between habitual dietary protein intake and dual task performance in sedentary, recreationally active, and masters athlete older adults
As the body ages, physical and cognitive declines can result in balance and mobility deficits, but research has shown that proper nutrition and exercise can help maintain physical and mental capacity. The purpose of this study was to analyze the relationship between habitual dietary protein intake and dual task performance in sedentary (SED), recreationally active (RA), and masters athletes (MA). To measure physical activity levels, the Rapid Physical Activity Questionnaire (RAPA) was completed by all participants. The participants were placed into a high or low protein group using the ASA-24 hour dietary recall. If the participant consumed less than 0.8 g/kg of protein per day, they were placed in the low protein group; if the participant consumed more than 0.8 g/kg of protein per day, they were placed in the high protein group. Participants completed four different walking tasks: habitual speed, maximal speed, dual-task habitual speed, and dual-task maximal speed. Gait speed was measured over a distance of 10 meters. SED, RA, and MA consumed a mean of 0.84, 1.13, and 1.57 grams of protein per kilogram body weight per day, respectively. MA consumed significantly more protein than SED or RA participants (α \u3c .05). The low protein group consumed 0.84 g/kg of protein ± 0.39 while the high protein group consumed 1.30 g/kg of protein ± 0.50. There was no significant correlation between amount of protein consumed and dual task performance. While the results were for dual task performance not statistically significant, they may have clinical significance; when comparing the high and low protein groups for the dual task habitual trial, the high protein group covered the 10-m distance 0.73 seconds faster than the low protein group. Clinically, the higher protein group may be able to perform activities of daily living more efficiently
The family and community lives of older people after the second world war: new evidence from York
No abstract available
Parallel projected variable metric algorithms for unconstrained optimization
The parallel variable metric optimization algorithms of Straeter (1973) and van Laarhoven (1985) are reviewed, and the possible drawbacks of the algorithms are noted. By including Davidon (1975) projections in the variable metric updating, researchers can generalize Straeter's algorithm to a family of parallel projected variable metric algorithms which do not suffer the above drawbacks and which retain quadratic termination. Finally researchers consider the numerical performance of one member of the family on several standard example problems and illustrate how the choice of the displacement vectors affects the performance of the algorithm
Computerized polar plots by a cathode ray tube/grid overlay method
Overlay is aligned with four calibration dots so it is not affected by CRT drift or changes in vertical or horizontal gain when producing Nyquist /frequency-response phase/amplitude/ plots. Method produces over 50 plots per hour
Computational Study of the Structure and Thermodynamic Properties of Ammonium Chloride Clusters Using a Parallel J-Walking Approach
The thermodynamic and structural properties of (NHCl) clusters,
n=3-10 are studied. Using the method of simulated annealing, the geometries of
several isomers for each cluster size are examined. Jump-walking Monte Carlo
simulations are then used to compute the constant-volume heat capacity for each
cluster size over a wide temperature range. To carry out these simulations a
new parallel algorithm is developed using the Parallel Virtual Machine (PVM)
software package. Features of the cluster potential energy surfaces, such as
energy differences among isomers and rotational barriers of the ammonium ions,
are found to play important roles in determining the shape of the heat capacity
curves.Comment: Journal of Chemical Physics, accepted for publicatio
Why Not Africa?
Various arguments have been used to explain Sub-Saharan Africa's economic decline. We find that a stress on investments in education as a prerequisite for more rapid growth is misplaced; that greater openness is far from sufficient to insure economic progress; that income inequality and urban bias are not so extreme as to foreclose prospects for more rapid growth and poverty alleviation; and that the constraints imposed by Sub-Saharan Africa's human and physical geography are not core explanations for the regions poor performance. If African countries can establish an institutional environment that enables individuals to gain the rewards of their investments, the alleged barriers to the region's growth should prove surmountable.
The Impact of Collective Bargaining: Illusion or Reality?
This paper reviews a significant body of evidence regarding the impact of trade unionism on economic performance and seeks to evaluate antithetical views regarding whether estimated differences between union and nonunion workers and firms represent: illusions created by poor experiments, real effects explicable solely in price-theoretic terms, or real effects which reflect the non wage-related dimensions of trade unions. The review yields conclusions on both the substantive questions at hand and the methodologies which have been used to address their validity. With respect to the illusion/reality debate, the preponderance of extant evidence indicates that union effects on a wide variety of economic variables estimated with cross-sectional data are real. Moreover, since the effects of unions on nonwage outcomes generally come from models which hold fixed the level of wages and variables affected by wages, the evidence supports the view that unions do much more than simply raise wages as an economic monopolist. While, in this study, we do not examine interpretations of these nonwage effects, the effects represent an empirical foundation for the "institutional" view of unionism, which is described in Section I. With respect to methods for evaluating the quality of standard cross-sectional experiments, some techniques appear more useful than others. In particular, we find that sensitivity analyses of single-equation results and longitudinal experiments provide valuable checks on cross-sectional findings while multiple-equations approaches produce results which are much too unstable to help resolve the questions of concern.
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