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The Relationships of Blood Pressure, Heart Rate and Body Weight to Aging in the Domestic Fowl12
1195
PROPERTIES OF EGGS Kline, L., J. J. Meehan and T. F. Sugihara, 1965. Relation between layer age and egg-product yields and quality. Food Tech. 19:1296-1301. Marion, J. E., J. G. Woodroof and R. E. Cook, 1965. Some physical and chemical properties of eggs from hens of five different stocks. Poultry Sci. 44: 529-534.
Marion, W. W., A. W. Nordskog, H. S. Tolman and R. H. Forsythe, 1964. Egg composition as influenced by breeding, egg size, age and season. Poultry Sci. 43: 255-264. May, K. N., and W. J. Stadelman, 1960. Some factors affecting components of eggs from adult hens. Poultry Sci. 39: 560-565.
H. D. MULLER AND M. E. CARROLL Colorado Agricultural Experiment Station, Department of Poultry Science, Fort Collins, Colorado (Received for publication January 29, 1966)
T
HE average systolic blood pressure of the domestic fowl had been reported to increase from 1 year to 3 to 4 years of age (Sturkie et al., 1953). Males were shown to increase 14 percent and females increased by 24 percent. The development of sex differences in the blood pressures of the chick have been investigated by Weiss et al. (1957). These investigators determined that a divergence of pressures began when the chicks were 8 to 13 weeks of age and depended primarily upon an increase in male systolic blood pressure. Nichols et al. (1963) determined the relationship between systolic blood pressure and body weight in cockerels and determined that blood pressure increased 2.02 mm. Hg per week of age or 8.46 mm. Hg per kilogram of body weight. In these investigations, heart rates of the females were significantly higher than those of the males. Heart rate was not causally related to body weight or blood pressure. Blood pressure showed little change with age or sex and no relationship was observed between heart rate or body weight and blood pressure. Unpub1 Published with the approval of the Director of the Colorado Agricultural Experiment Station as Scientific Series Paper No. 1089. 'Supported by USAEC Grant At-(ll-l)-1119.
lished results indicated deviations from these patterns and offered additional information for the elucidation of these cardiovascular patterns concomitant with aging. The reported investigation and analyses were undertaken for the purposes of comparison and interposition with those in evidence. PROCEDURE
Twenty-eight male and 28 female Single Comb White Leghorns which constituted the control groups of a longevity investigation were measured from 14 to 40 months of age for systolic and diastolic blood pressures, heart rates and body weights. These determinations were conducted at monthly intervals from 14 to 17 months of age and at bi-monthly intervals for the duration of the investigation. Blood pressure and heart rate determinations were obtained with a type RS Dynograph* assembly equipped with a heart rate coupler which had been modified to record up to 500 beats/minute. Using the procedure of Sturkie et al. (1957) a capacitance pulse pickup (Infraton)* was placed against the artery in the lower thigh * Beckman Instruments, Inc., Spinco Division, Palo Alto, California.
Downloaded from http://ps.oxfordjournals.org/ at Rutgers University Libraries/Technical Services on April 13, 2015
The Relationships of Blood Pressure, Heart Rate and Body Weight to Aging in the Domestic Fowl1'2
1196
H. D. MULLER AND M. E. CARROLL
TABLE 1.—Mean values and standard errors for the blood pressures, heart rates and body weights of S. C. White Leghorns at 14, 24, 36 and 40 months of age1,2 Males
Females 1
Mean
S.E.1
8.20 8.25 9.24 .049
30 30 29 30
149 43 359 1.905
7.56 4.89 15.41 .059
200 87 355 2.903
9.20 7.81 6.06 .054
29 29 29 29
144 40.2 374 2.131
6.36 4.74 6.71 .081
28 28 28 28
198 94 346 2.948
10.51 10.28 6.09 .049
30 30 30 30
130 30 366 2.177
11.50 2.06 6.25 .073
28 28 28 28
234 119 325 2.948
7.37 7.53 10.48 .059
24 24 24 24
137 36 351 2.358
8.84 6.55 6.35 .104
Mean
S.E.
14 months Systolic blood pressure Diastolic blood pressure Heart rate (beats/min.) Body weight (kg.)
28 28 27 28
207 61 329 2.676
24 months Systolic blood pressure Diastolic blood pressure Heart rate (beats/min.) Body weight (kg.)
28 28 28 28
36 months Systolic blood pressure Diastolic blood pressure Heart rate (beats/min.) Body weight (kg.) 40 months Systolic blood pressure Diastolic blood pressure Heart rate (beats/min.) Body weight (kg.)
• Standard error of the mean; VsVn. 1 Blood pressures were recorded indirectly in mm. Hg.
of the animal. A one inch cuff was then wrapped about the pickup and thigh. The cuff was inflated to occlude the pulse and then gradually deflated. Return of the pulse indicated systolic blood pressure. The point at which the amplitude of the wave returned to normal was considered the diastolic pressure. During the collection of the indirect pressure recordings the birds were restrained in a comfortable upright position with the right leg extended and secured for application of the cuff and pulse pickup. All measurements were recorded directly on chart paper. Birds were maintained in a longevity complex where each individual was maintained in a welded wire cage measuring 18 inches wide, 24 inches deep and 18 inches high. Each cage was equipped with a 1 X 2 inch roost. Feed and water were provided to the birds ad libitum. RESULTS AND DISCUSSION When the mean values for the blood pressure, heart rate and body weights of
Single Comb White Leghorns at 14, 24, 36 and 40 months of age were compared (Table 1) it was apparent that the mean systolic blood pressure of these individuals did not increase in the proportions reported by Sturkie et al. (1953). Mean systolic blood pressures of the males did not increase until they attained 40 months of age, where the increase was 13 percent above that of the 14 month measurement. For the females the systolic blood pressures decreased eight percent from 14 to 40 months of age. The diastolic blood pressure of the males increased 40 percent, 54 percent and 95 percent respectively from 14 to 24, from 24 to 36 and from 36 to 40 months of age. For the females the diastolic blood pressures actually decreased from 14 to 40 months of age. The heart rates did not undergo any observable changes with increasing age of either sex. Highly significant correlations between systolic and diastolic blood pressures (Table 2) were found at each of the ages
Downloaded from http://ps.oxfordjournals.org/ at Rutgers University Libraries/Technical Services on April 13, 2015
n
n
1197
AGING IN THE FOWL TABLE 2.-—Correlation coefficients of
systolic and diastolic blood pressures, heart rates and body weights of S. C. White Leghorns at 14, 24, 36 and 40 months of age Males Age in months 14 442* 454 104 117 128 .009
24 .956** .118 .167 .463" .394* .294
36
40
14
24
.986** -.097 -.076 .363* .339 .386*
.876** -.224 -.038 -.179 -.162 .286
.434* .066 -.350* .452** .440* .041
.885** -.027 .021 .162 .175 -.164
36 .822** .216 .291 .320 .217 .034
40 .842" .032 -.025 .654' .481' .046
* Significant at the .05 level. ** Significant at the .01 level.
reported. Between diastolic blood pressure and heart rate only one significant correlation was discernible. However, significant correlations between blood pressures and body weights were observed for males at 24 and 36 months of age, and for females at 14 and 40 months of age. This relationship appears to be based upon the females continued increase in body weight even at 40 months of age, after the males had plateaued and reached a stable body weight. When heart rate and body weight were compared at these four age intervals, only one significant relationship between these measurements was indicated. Table 3 shows the average values for both systolic and diastolic blood pressures, heart rates and body weights found at each
of the periods investigated from 14 to 40 months of age. Inspection of this table reveals that considerable variation existed from period to period although these periods were one month apart from 14-17 months of age and two months apart from 22-40 months of age. Widely distributed systolic pressures have also been reported by Sturkie et al. (1956). Correlation values and exterpolations extracted from data at any period other than those selected might well have altered the reported results. The 14, 24, 36 and 40 month periods were selected as the initial and terminal periods as well as those representing even one-year intervals of age. The means and standard errors reported for 14, 24, 36 and 40 months of age, however, may serve as rea-
TABLE 3.—Mean values for the blood pressures, heart rates and body weights of S. C. White Leghorns from 14 to 40 months of age Females
Males Age in months
14 15 16 17 19 22 24 26 28 30 32 34 36 38 40
Systolic B.P. mm. Hg 207 210 187 219 156 211 200 192 197 193 208 198 213 226 234
Body Heart Diastolic weight B.P. rate mm. Hg Beats/Min. kg. 61 77 61 76 51 98 87 77 85 76 83 94 104 108 119
329 341 354 340 356 361 355 355 349 345 357 346 353 340 325
2.677 2.721 2.721 2.812 2.812 2.767 2.903 2.812 2.857 2.857 2.903 2.948 2.993 2.948 2.948
Systolic B.P. mm. Hg 149 138 119 124 149 118 144 131 124 142 141 130 125 136 137
Body Heart Diastolic weight B.P. rate mm. Hg Beats/Min. kg43 36 30 29 39 30 40 36 30 42 42 30 35 38 36
359 357 369 362 376 364 374 369 357 377 354 366 362 367 351
1.904 1.950 1.996 1.950 1.950 1.950 2.132 2.132 2.177 2.041 2.132 2.177 2.177 2.268 2.358
Downloaded from http://ps.oxfordjournals.org/ at Rutgers University Libraries/Technical Services on April 13, 2015
Systolic B.P. and diastolic B.P. Systolic B.P. and heart rate Diastolic B.P. and heart rate Systolic B.P. and body weight Diastolic B.P. and body weight Heart rate and body weight
Females Age in months
1198
H. D. MULLER AND M. E. CARROLL
sonable guides for the blood pressures and heart rates of the domestic fowl at these ages but the deviations observed must be given recognition. DISCUSSION
SUMMARY
The influence of advancing age on blood pressure, heart rate and body weight has been investigated. Males responded with greater increases in both systolic and diastolic blood pressure than did females. Heart rate and body weight do not appear to be greatly influenced by senility. Correlations established between blood pressures, heart rates and body weights demonstrated significant relationships between body weights and blood pressures at several intervals between 14 and 40 months of age. There was little indication of relationship between heart rate or body weight and aging. Sexual dimorphism in responses, particularly blood pressures, indicates that the sexes must be considered independently when these physiological mechanisms are evaluated. Considerable variations were found to exist from measurement period to measurement period within each subsequent year of age evaluated. These fluctuations could account for much of the variation in reported values. REFERENCES Nichols, E. L., D. K. Hotchkiss and S. L. Balloun, 1963. Effect of age and body weight on the systolic blood pressure of the growing chicken. Poultry Sci. 42: 1465-1466. Sturkie, P. D., H. S. Weiss and R. K. Ringer, 1953. Effects of age on blood pressure in the chicken. Am. J. Physiol. 174: 405-407. Sturkie, P. D., R. K. Ringer and H. S. Weiss, 1956. Relationship of blood pressure to mortality in chickens. Proc. Soc. Exp. Biol. Med. 92: 301-303. Sturkie, P. D., W. Durfee and M. M. Sheahan, 1957. Demonstration of an improved method for measuring blood pressure in birds. Poultry Sci. 36: 1161. Weiss, H. S., R. K. Ringer and P. D. Sturkie, 1957. Development of sex differences in blood pressure of the chick. Am. J. Physiol. 188: 383386.
Downloaded from http://ps.oxfordjournals.org/ at Rutgers University Libraries/Technical Services on April 13, 2015
From this data it appears that the systolic blood pressure of the male fowl increases 13 percent from 14 to 40 months of age while the systolic blood pressure of the females decreases with advancing age. The diastolic blood pressure of the male increased by 97.5 percent from 14 to 40 months of age, while the diastolic blood pressure of the female decreases by approximately 16 percent during the same period. Heart rate does not appear to be influenced by advancing age and can, therefore, be considered independent of blood pressure and age. In accord with the results of Sturkie et al. (1953), there was no observed relationship between heart rate and body weight. However, relationships did manifest themselves between blood pressures and body weights, particularly for the females at 14 and 40 months of age and the males at 24 and 36 months of age. The distinct separation of sex, age and correlation of measurements provides a fertile area for conjecture, particularly with regard to physiological mechanisms. Sexual dimorphism in the blood pressure responses clearly indicates that the sexes must be considered independently. Since the Experiment Station at which these investigations were performed is located at an altitude of 5,200 feet, it is possible that altitude would exert its influence by causing the blood pressures to be elevated slightly from those reported at sea level stations. Since the experimental birds were acclimated and housed in a facility designed to provide minimum stress, it is also possible that they either did not encounter the stresses of confinement or did not react
with the cardiovascular deviations encountered under more confined conditions.
PROPERTIES OF EGGS Kline, L., J. J. Meehan and T. F. Sugihara, 1965. Relation between layer age and egg-product yields and quality. Food Tech. 19:1296-1301. Marion, J. E., J. G. Woodroof and R. E. Cook, 1965. Some physical and chemical properties of eggs from hens of five different stocks. Poultry Sci. 44: 529-534.
Marion, W. W., A. W. Nordskog, H. S. Tolman and R. H. Forsythe, 1964. Egg composition as influenced by breeding, egg size, age and season. Poultry Sci. 43: 255-264. May, K. N., and W. J. Stadelman, 1960. Some factors affecting components of eggs from adult hens. Poultry Sci. 39: 560-565.
H. D. MULLER AND M. E. CARROLL Colorado Agricultural Experiment Station, Department of Poultry Science, Fort Collins, Colorado (Received for publication January 29, 1966)
T
HE average systolic blood pressure of the domestic fowl had been reported to increase from 1 year to 3 to 4 years of age (Sturkie et al., 1953). Males were shown to increase 14 percent and females increased by 24 percent. The development of sex differences in the blood pressures of the chick have been investigated by Weiss et al. (1957). These investigators determined that a divergence of pressures began when the chicks were 8 to 13 weeks of age and depended primarily upon an increase in male systolic blood pressure. Nichols et al. (1963) determined the relationship between systolic blood pressure and body weight in cockerels and determined that blood pressure increased 2.02 mm. Hg per week of age or 8.46 mm. Hg per kilogram of body weight. In these investigations, heart rates of the females were significantly higher than those of the males. Heart rate was not causally related to body weight or blood pressure. Blood pressure showed little change with age or sex and no relationship was observed between heart rate or body weight and blood pressure. Unpub1 Published with the approval of the Director of the Colorado Agricultural Experiment Station as Scientific Series Paper No. 1089. 'Supported by USAEC Grant At-(ll-l)-1119.
lished results indicated deviations from these patterns and offered additional information for the elucidation of these cardiovascular patterns concomitant with aging. The reported investigation and analyses were undertaken for the purposes of comparison and interposition with those in evidence. PROCEDURE
Twenty-eight male and 28 female Single Comb White Leghorns which constituted the control groups of a longevity investigation were measured from 14 to 40 months of age for systolic and diastolic blood pressures, heart rates and body weights. These determinations were conducted at monthly intervals from 14 to 17 months of age and at bi-monthly intervals for the duration of the investigation. Blood pressure and heart rate determinations were obtained with a type RS Dynograph* assembly equipped with a heart rate coupler which had been modified to record up to 500 beats/minute. Using the procedure of Sturkie et al. (1957) a capacitance pulse pickup (Infraton)* was placed against the artery in the lower thigh * Beckman Instruments, Inc., Spinco Division, Palo Alto, California.
Downloaded from http://ps.oxfordjournals.org/ at Rutgers University Libraries/Technical Services on April 13, 2015
The Relationships of Blood Pressure, Heart Rate and Body Weight to Aging in the Domestic Fowl1'2
1196
H. D. MULLER AND M. E. CARROLL
TABLE 1.—Mean values and standard errors for the blood pressures, heart rates and body weights of S. C. White Leghorns at 14, 24, 36 and 40 months of age1,2 Males
Females 1
Mean
S.E.1
8.20 8.25 9.24 .049
30 30 29 30
149 43 359 1.905
7.56 4.89 15.41 .059
200 87 355 2.903
9.20 7.81 6.06 .054
29 29 29 29
144 40.2 374 2.131
6.36 4.74 6.71 .081
28 28 28 28
198 94 346 2.948
10.51 10.28 6.09 .049
30 30 30 30
130 30 366 2.177
11.50 2.06 6.25 .073
28 28 28 28
234 119 325 2.948
7.37 7.53 10.48 .059
24 24 24 24
137 36 351 2.358
8.84 6.55 6.35 .104
Mean
S.E.
14 months Systolic blood pressure Diastolic blood pressure Heart rate (beats/min.) Body weight (kg.)
28 28 27 28
207 61 329 2.676
24 months Systolic blood pressure Diastolic blood pressure Heart rate (beats/min.) Body weight (kg.)
28 28 28 28
36 months Systolic blood pressure Diastolic blood pressure Heart rate (beats/min.) Body weight (kg.) 40 months Systolic blood pressure Diastolic blood pressure Heart rate (beats/min.) Body weight (kg.)
• Standard error of the mean; VsVn. 1 Blood pressures were recorded indirectly in mm. Hg.
of the animal. A one inch cuff was then wrapped about the pickup and thigh. The cuff was inflated to occlude the pulse and then gradually deflated. Return of the pulse indicated systolic blood pressure. The point at which the amplitude of the wave returned to normal was considered the diastolic pressure. During the collection of the indirect pressure recordings the birds were restrained in a comfortable upright position with the right leg extended and secured for application of the cuff and pulse pickup. All measurements were recorded directly on chart paper. Birds were maintained in a longevity complex where each individual was maintained in a welded wire cage measuring 18 inches wide, 24 inches deep and 18 inches high. Each cage was equipped with a 1 X 2 inch roost. Feed and water were provided to the birds ad libitum. RESULTS AND DISCUSSION When the mean values for the blood pressure, heart rate and body weights of
Single Comb White Leghorns at 14, 24, 36 and 40 months of age were compared (Table 1) it was apparent that the mean systolic blood pressure of these individuals did not increase in the proportions reported by Sturkie et al. (1953). Mean systolic blood pressures of the males did not increase until they attained 40 months of age, where the increase was 13 percent above that of the 14 month measurement. For the females the systolic blood pressures decreased eight percent from 14 to 40 months of age. The diastolic blood pressure of the males increased 40 percent, 54 percent and 95 percent respectively from 14 to 24, from 24 to 36 and from 36 to 40 months of age. For the females the diastolic blood pressures actually decreased from 14 to 40 months of age. The heart rates did not undergo any observable changes with increasing age of either sex. Highly significant correlations between systolic and diastolic blood pressures (Table 2) were found at each of the ages
Downloaded from http://ps.oxfordjournals.org/ at Rutgers University Libraries/Technical Services on April 13, 2015
n
n
1197
AGING IN THE FOWL TABLE 2.-—Correlation coefficients of
systolic and diastolic blood pressures, heart rates and body weights of S. C. White Leghorns at 14, 24, 36 and 40 months of age Males Age in months 14 442* 454 104 117 128 .009
24 .956** .118 .167 .463" .394* .294
36
40
14
24
.986** -.097 -.076 .363* .339 .386*
.876** -.224 -.038 -.179 -.162 .286
.434* .066 -.350* .452** .440* .041
.885** -.027 .021 .162 .175 -.164
36 .822** .216 .291 .320 .217 .034
40 .842" .032 -.025 .654' .481' .046
* Significant at the .05 level. ** Significant at the .01 level.
reported. Between diastolic blood pressure and heart rate only one significant correlation was discernible. However, significant correlations between blood pressures and body weights were observed for males at 24 and 36 months of age, and for females at 14 and 40 months of age. This relationship appears to be based upon the females continued increase in body weight even at 40 months of age, after the males had plateaued and reached a stable body weight. When heart rate and body weight were compared at these four age intervals, only one significant relationship between these measurements was indicated. Table 3 shows the average values for both systolic and diastolic blood pressures, heart rates and body weights found at each
of the periods investigated from 14 to 40 months of age. Inspection of this table reveals that considerable variation existed from period to period although these periods were one month apart from 14-17 months of age and two months apart from 22-40 months of age. Widely distributed systolic pressures have also been reported by Sturkie et al. (1956). Correlation values and exterpolations extracted from data at any period other than those selected might well have altered the reported results. The 14, 24, 36 and 40 month periods were selected as the initial and terminal periods as well as those representing even one-year intervals of age. The means and standard errors reported for 14, 24, 36 and 40 months of age, however, may serve as rea-
TABLE 3.—Mean values for the blood pressures, heart rates and body weights of S. C. White Leghorns from 14 to 40 months of age Females
Males Age in months
14 15 16 17 19 22 24 26 28 30 32 34 36 38 40
Systolic B.P. mm. Hg 207 210 187 219 156 211 200 192 197 193 208 198 213 226 234
Body Heart Diastolic weight B.P. rate mm. Hg Beats/Min. kg. 61 77 61 76 51 98 87 77 85 76 83 94 104 108 119
329 341 354 340 356 361 355 355 349 345 357 346 353 340 325
2.677 2.721 2.721 2.812 2.812 2.767 2.903 2.812 2.857 2.857 2.903 2.948 2.993 2.948 2.948
Systolic B.P. mm. Hg 149 138 119 124 149 118 144 131 124 142 141 130 125 136 137
Body Heart Diastolic weight B.P. rate mm. Hg Beats/Min. kg43 36 30 29 39 30 40 36 30 42 42 30 35 38 36
359 357 369 362 376 364 374 369 357 377 354 366 362 367 351
1.904 1.950 1.996 1.950 1.950 1.950 2.132 2.132 2.177 2.041 2.132 2.177 2.177 2.268 2.358
Downloaded from http://ps.oxfordjournals.org/ at Rutgers University Libraries/Technical Services on April 13, 2015
Systolic B.P. and diastolic B.P. Systolic B.P. and heart rate Diastolic B.P. and heart rate Systolic B.P. and body weight Diastolic B.P. and body weight Heart rate and body weight
Females Age in months
1198
H. D. MULLER AND M. E. CARROLL
sonable guides for the blood pressures and heart rates of the domestic fowl at these ages but the deviations observed must be given recognition. DISCUSSION
SUMMARY
The influence of advancing age on blood pressure, heart rate and body weight has been investigated. Males responded with greater increases in both systolic and diastolic blood pressure than did females. Heart rate and body weight do not appear to be greatly influenced by senility. Correlations established between blood pressures, heart rates and body weights demonstrated significant relationships between body weights and blood pressures at several intervals between 14 and 40 months of age. There was little indication of relationship between heart rate or body weight and aging. Sexual dimorphism in responses, particularly blood pressures, indicates that the sexes must be considered independently when these physiological mechanisms are evaluated. Considerable variations were found to exist from measurement period to measurement period within each subsequent year of age evaluated. These fluctuations could account for much of the variation in reported values. REFERENCES Nichols, E. L., D. K. Hotchkiss and S. L. Balloun, 1963. Effect of age and body weight on the systolic blood pressure of the growing chicken. Poultry Sci. 42: 1465-1466. Sturkie, P. D., H. S. Weiss and R. K. Ringer, 1953. Effects of age on blood pressure in the chicken. Am. J. Physiol. 174: 405-407. Sturkie, P. D., R. K. Ringer and H. S. Weiss, 1956. Relationship of blood pressure to mortality in chickens. Proc. Soc. Exp. Biol. Med. 92: 301-303. Sturkie, P. D., W. Durfee and M. M. Sheahan, 1957. Demonstration of an improved method for measuring blood pressure in birds. Poultry Sci. 36: 1161. Weiss, H. S., R. K. Ringer and P. D. Sturkie, 1957. Development of sex differences in blood pressure of the chick. Am. J. Physiol. 188: 383386.
Downloaded from http://ps.oxfordjournals.org/ at Rutgers University Libraries/Technical Services on April 13, 2015
From this data it appears that the systolic blood pressure of the male fowl increases 13 percent from 14 to 40 months of age while the systolic blood pressure of the females decreases with advancing age. The diastolic blood pressure of the male increased by 97.5 percent from 14 to 40 months of age, while the diastolic blood pressure of the female decreases by approximately 16 percent during the same period. Heart rate does not appear to be influenced by advancing age and can, therefore, be considered independent of blood pressure and age. In accord with the results of Sturkie et al. (1953), there was no observed relationship between heart rate and body weight. However, relationships did manifest themselves between blood pressures and body weights, particularly for the females at 14 and 40 months of age and the males at 24 and 36 months of age. The distinct separation of sex, age and correlation of measurements provides a fertile area for conjecture, particularly with regard to physiological mechanisms. Sexual dimorphism in the blood pressure responses clearly indicates that the sexes must be considered independently. Since the Experiment Station at which these investigations were performed is located at an altitude of 5,200 feet, it is possible that altitude would exert its influence by causing the blood pressures to be elevated slightly from those reported at sea level stations. Since the experimental birds were acclimated and housed in a facility designed to provide minimum stress, it is also possible that they either did not encounter the stresses of confinement or did not react
with the cardiovascular deviations encountered under more confined conditions.