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81.
Loss of stature in certain elderly subjects can be attributed to diseases such as osteoporosis, as well as to age and generational effects. In addition, many elders cannot stand straight for accurate measurement. For these cases, total height can be estimated with regression equations based on knee height. The aims of this study were, firstly, to evaluate the applicability of regression equations based on knee height for estimation of stature and, secondly, to document the differences between measured and estimated height in a group of elderly Hispanics with postural problems (n = 166) in comparison with a group of elderly Hispanic without postural problems (n = 270). Using both, estimated and measured height, we also calculated the body mass index (BMI) of both groups of elders. Statistical analyses were done with paired t-tests, within sex and study group. Within the group with postural problems, estimated height was higher than the measured height for both men (p < or = 0.001) and women (p < or = 0.001). There were no significant differences between measured and estimated height in the group without postural problems. Furthermore, in the group with postural problems, BMI values calculated with estimated height were lower than those estimated with the measured height, and these differences were also significant for both men (p < or = 0.001) and women (p < or = 0.001). With the aging of the Latin American population, there is a need for more nutrition and health research among elders. In order to do this we need to develop and use methods and criteria appropriate for each population. 相似文献
82.
Since the initial report in 1978 of galactopoietic effects of a photoperiod of 16 h of light:8 h of darkness, numerous studies have confirmed long-day stimulation of milk yield. The endocrine factor(s) responsible for increased milk yield, however, has eluded identification. Recent studies suggest that insulin-like growth factor-I (IGF-I) may mediate the galactopoietic response to long day photoperiod. Indeed, long days increase IGF-I in heifers and lactating cows; in the latter case, the response preceded an increase in milk yield. In heifers and cows, the increase in IGF-I is independent of changes in circulating growth hormone. Melatonin feeding to mimic a short-day photoperiod suppressed the increase of IGF-I in heifers induced by long days. However, melatonin feeding had no effect on milk yield in cows. Despite lack of resolution of the endocrine mechanism, dairy producers are interested in how photoperiod management can be integrated with current practices throughout the lactation cycle. There is strong evidence that milk yield responses to long days persist through an entire lactation. Also, long days can be combined with bovine somatotropin (bST) to produce additive increases in milk yield. During the dry period, long days increase the periparturient surge of prolactin. However, relative to long days, short-day treatment during the dry period produces the largest magnitude of response in milk yield during the subsequent lactation. The response to short days during the dry period may be due to a priming effect on the photoperiodic response system. In summary, IGF-I has emerged as a possible mediator of the increase of milk yield in response to long-day photoperiod. Photoperiod can be combined effectively with other management techniques such as bST. Consideration of photoperiod management during the dry period is essential to maximize responses during the subsequent lactation. 相似文献
83.
J Foden-Shroff CW Redman H Tucker J Millinship E Thomas A Warwick PW Jones 《Canadian Metallurgical Quarterly》1998,105(9):1022-1025
AIMS: To determine functional results after unilateral and bilateral cataract surgery in children with different aphakic optical correction. METHODS: In this retrospective study, we evaluated visual acuity and binocular vision in 107 children who underwent cataract surgery during the 10 year period from 1985 to 1995. Aphakia was corrected by an intracapsular intraocular lens (IOL), spectacles or contact lenses. RESULTS: Mean visual acuity was > 20/40 (< 0.3 log MAR) with normal binocular vision in 58 children over 7 months of age operated on for bilateral cataracts. Pseudophakic eyes regained visual acuity > 20/63 (< 0.5 log MAR) more often (90%) than aphakic eyes (46%) (p < 0.001). Binocular vision was also achieved more often after IOL implantation (p < 0.001). Visual outcome of early bilateral cataracts was less satisfactory in children with abnormal foveolar function. For 49 children who had surgery for unilateral cataracts, prognosis was poor when surgery was performed before the age of 7 months. For cataract surgery in older children (> or = 7 months) mean visual acuities were better with IOL implantation (p < 0.05). CONCLUSION: Cataract surgery with unilateral and bilateral IOL implantation can provide a beneficial effect on final visual outcome in children who are operated on before abnormal foveolar function develops. 相似文献
84.
RT Withers DA Smith RC Tucker M Brinkman DG Clark 《Canadian Metallurgical Quarterly》1998,84(4):1333-1340
This study examined differences between long-term exercising (LE) and long-term nonexercising (LNE) women [n = 24; age 56.4 +/- 6.2 (SD) yr] for resting metabolic rate (RMR) and energy expenditure in the free-living state by using doubly labeled water (DLW). There was a statistically significant difference (P = 0.0002) between the 12 LE (94.85 +/- 8.44 kJ . kg-1 . day-1) and 12 LNE (81.16 +/- 6.62 kJ . kg-1 . day-1) for RMR, but this difference was only marginally significant (P = 0.06) when the data (MJ/day) were subjected to an analysis of covariance with fat-free mass as the covariate. The DLW data indicated that the eight most active LE (12.99 +/- 3.58 MJ/day) expended significantly (P = 0.01) more energy than did the eight least active LNE (9.30 +/- 1.15 MJ/day). Energy expenditures ranged from 7.64 to 18.15 MJ/day, but there was no difference (P = 0.96) between the LE and LNE in energy expenditure during activity that was not designed to either improve or maintain fitness. These cross-sectional data on 49- to 70-yr-old women therefore suggest that 1) aerobic-type training results in a greater RMR per unit of body mass and also when statistical control is exerted for the effect of the metabolically active fat-free mass, 2) there is a large range in the energy intake necessary to maintain energy balance, and 3) aerobic training does not result in a compensatory reduction in energy expenditure during the remainder of the day. 相似文献
85.
Examined nurse–patient agreement on behaviors and attitudes associated with patient adjustment to chronic hemodialysis treatment. 164 hemodialysis nurses and 79 chronic hemodialysis outpatients completed a patient adjustment to dialysis inventory consisting of 43 behaviors and attitudes reported by nurses in earlier research to be important for adjustment to chronic hemodialysis. Results show that over 60% of nurses and patients showed sufficient agreement on the importance of 33 of 43 behaviors and attitudes for patient adjustment in the areas of compliance with the medical regimen, involvement in treatment, patient–staff interactions, and psychological and social functioning. Nurses and patients disagreed as to whether 9 behaviors and attitudes were at least important, while agreeing that only 1 item was irrelevant. Results also show that significantly more patients than nurses rated 25 out of 43 behaviors and attitudes as crucial. Approximately 50% of these related to interacting with staff, family, and friends. It is suggested that social and psychological criteria for adjustment to hemodialysis treatment should be defined by nurses and patients together. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
86.
Reviews literature on problem-solving models, their application to psychology and other fields, models of supervision, and supervision in psychology. The following processes are addressed: problem identification, generation of alternative solutions, solution evaluation, decision making, performance, and outcome evaluation. Implementation of the problem-solving model and possible sources of difficulty are discussed. This model has the advantages of being atheoretical, systematic, and appropriate for use in clinical, counseling, and school psychology. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
87.
A two-dimensional, mesoscale model of the atmosphere that incorporates hydrodynamic, thermodynamic, and microphysical processes has been applied to simulate the impact on regional weather of a solar thermal electric conversion (STEC) installation in southern Spain. The STEC plant is conceptualized to occupy an area of 1,000 km2 with heliostats covering 25 per cent of the total power plant area. It is assumed to use wet natural draft cooling towers for dissipating waste heat into the atmosphere.The 2-D model is applied to a STEC facility that covers a distance of 32 km in the horizontal with heliostats installed in the middle over a distance of 8 km. The model has been integrated for 9 hr of real time for both typical summer and winter conditions.The results of integration for summer indicate that a STEC installation of the above size has considerable potential for modifying regional weather. Clouds formed after 5 hr of real-time integration and persisted until the end of the integration; rainfall also occurred. In contrast, clouds did not form until 7 hr of real-time integration without the installation and were more sporadic and transient; rainfall was much less.The results for winter conditions do not show any cloud formation after 9 hr of real-time integration. This difference between summer and winter cases is attributed to the very strong winds used as initial conditions for the winter simulation. 相似文献
88.
It is shown that the equivalent circuits used by van der Graaf, while giving perfectly correct results for the problems to which he applied them, lack general validity, even within the conditions assumed by him. In particular they appear to demonstrate that it is possible to obtain a constant input resistance (i.e. constant with respect to time) in a series or shunt modulator, whereas clearly such a result is impossible in reality. An alternative system of equivalent circuits is shown to avoid the difficulty. An explanation is given. 相似文献
89.
90.
A finite-difference technique is used to compute exact solutions to the diffusion equation describing fission gas release from UO2 nuclear fuel during steady reactor operation. The resolution of gas atoms from grain-boundary bubbles is treated in two alternative ways, and the results of the parallel calculations compared. Predictions of gas release using simple analytical models are compared with the numerical results and are found in general to describe the process very accurately. 相似文献