The Rate of Change of Mouth Occlusion Pressure during Exercise

1979 ◽  
Vol 56 (5) ◽  
pp. 455-461 ◽  
Author(s):  
N. Siafakas ◽  
A. J. R. Morris ◽  
F. J. Prime
Keyword(s):  
Steady State ◽  
Linear Relationship ◽  
Regression Line ◽  
Constant Load ◽  
Rate Of Change ◽  
Significant Linear Relationship ◽  
Progressive Exercise ◽  
The Difference ◽  
Mouth Occlusion Pressure ◽  
The Relationship

1. The initial rate of change of pressure at the mouth (dP/dt) during a brief occlusion of the airways at the beginning of inspiration has been estimated in nine healthy subjects at rest, during exercise and during the first 2 min of recovery. Exercise was carried out with progressively increasing loads to the maximum tolerated (progressive exercise) and also for a period of 6 min at a constant load of 60% of the maximum (steady-state exercise). 2. A highly significant linear relationship was found between work loads and dP/dt during progressive exercise in all our subjects. 3. A highly significant linear relationship was found between ventilation and dP/dt in both forms of exercise, but the slope of the regression line was steeper during progressive than during steady-state exercise in six out of nine subjects. 4. The pattern of breathing (VT, f, VT/Tinsp., Tinsp./Ttot.) did not account for the difference in the relationship between dP/dt and ventilation during the two forms of exercise. 5. These results are in agreement with the hypothesis that dP/dt is an index of central inspiratory drive.

The relationship between steady-state transpiration rates and leaf water potential in cassava (Manihot esculenta cv. Llanera)

1978 ◽  
Vol 56 (13) ◽  
pp. 1537-1539 ◽  
Author(s):  
I. F. Ike ◽  
G. W. Thurtell ◽  
K. R. Stevenson
Keyword(s):  
Steady State ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Manihot Esculenta ◽  
Regression Line ◽  
Leaf Water ◽  
Dew Point ◽  
Manihot Esculenta Crantz ◽  
The Relationship

The relationship between leaf water potential (ψL) and transpiration rate (T) was investigated using indoor-grown cassava plants (Manihot esculenta Crantz cv. Llanera). Leaf water potentials were measured with in situ dew-point hygrometer and transpiration rates by gas exchange analysis technique.Regression analyses of the data showed that T was consistently linearly related to ψL (r2 = 0.94). This implies that the plant resistance to flow was constant and hence that an Ohm's Law analog is valid for the transpiration range studied. Extrapolated values of leaf water potential at zero transpiration were close to the osmotic potential of the nutrient solution. Calculated resistance values (slope of regression line for individual plants) varied between 2.90 and 3.05 bars dm2 h g−1 (1 bar = 100 kPa).

scholarly journals The use of intragastric nutrition to study saliva secretion and the relationship between rumen osmotic pressure and water transport

1995 ◽  
Vol 73 (2) ◽  
pp. 155-161 ◽  
Author(s):  
G. Y. Zhao ◽  
M. Durić ◽  
N. A. Macleod ◽  
E. R. ØRskov ◽  
F. D. Deb. Hovell ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Osmotic Pressure ◽  
Water Transport ◽  
Rumen Fluid ◽  
Salivary Secretion ◽  
Saliva Secretion ◽  
Key Factor ◽  
The Difference ◽  
Water Outflow ◽  
The Relationship

Four sheep sustained by intragastric nutrition were used to study saliva secretion and the relationship between osmotic pressure in the rumen and net water transport across the rumen wall. Different concentrations of buffer were infused into the rumen to change the rumen osmotic pressure. Salivary secretion was estimated from entrance of P into the rumen. Net water transport across the rumen wall was calculated as the difference between water inflow and water outflow from the rumen. A negative linear relationship between the rumen osmotic pressure (X, mOsm/kg) and the water absorption across the rumen wall (Y, ml/h) was found: Y = (394 SE 8·3)–(l·22 SE 0·03) X, r20·83, (P < 0·001), and a positive linear relationship was found between the rumen osmotic pressure (X, mOsm /kg) and the outflow rate of rumen fluid (Y, ml/h): Y = (34·0 SE 8·0) + (0·97 SE 0·03), X, r2 0·56, (P < 0·001). The implication is that rumen osmotic pressure can be a key factor in the control of the net water transport across the rumen wall, the outflow of rumen fluid to omasum and the rumen liquid dilution rate. A method is suggested by which salivary secretion in sheep may be calculated from the water balance in the rumen.

scholarly journals Relationship between Tree Richness and Temporary Stability of Plant Communities: A Case Study of a Forest in Northeast China

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1756
Author(s):  
Zhiyuan Jia ◽  
Shusen Ge ◽  
Yutang Li ◽  
Dongwei Kang ◽  
Junqing Li
Keyword(s):  
Linear Relationship ◽  
Northeast China ◽  
Field Survey ◽  
Community Characteristics ◽  
Additional Information ◽  
Significant Linear Relationship ◽  
New Perspective ◽  
The Relationship ◽  
Stability Of Plant Communities

The relationship between diversity and stability is a classic issue in ecology, but no general consensus has been achieved. To address this relationship, a field survey of a forest in Northeast China was conducted. The temporary stability was defined from the perspective of community characteristics. The results showed that communities with the highest temporary stability value were characterized by a single dominant species. A significant linear relationship with a low R2 value was observed between temporary stability and tree richness. When dominant and non-dominant tree species were studied, no significant linear relationship was obtained between temporary stability and non-dominant tree richness. However, the relationship between temporary stability and dominant tree richness was significant with a high R2 value, and the temporary stability decreased with increasing dominant tree richness. This study demonstrates that dominant tree richness is closely related to temporary stability, and temporary stability can serve as a stability indicator. The results provide a new perspective for understanding stability and additional information for revealing the relationship between diversity and stability in forest ecosystems.

scholarly journals The Relationship between Age of Air and the Diabatic Circulation of the Stratosphere

2016 ◽  
Vol 73 (11) ◽  
pp. 4507-4518 ◽  
Author(s):  
Marianna Linz ◽  
R. Alan Plumb ◽  
Edwin P. Gerber ◽  
Aditi Sheshadri
Keyword(s):  
Steady State ◽  
General Circulation ◽  
Circulation Model ◽  
State Theory ◽  
Time Dependent ◽  
Absolute Value ◽  
Dependent Theory ◽  
The Difference ◽  
Using Data ◽  
The Relationship

Abstract The strength of the Brewer–Dobson circulation is difficult to estimate using observations. Trends in the age of stratospheric air, deduced from observations of transient tracers, have been used to identify trends in the circulation, but there are ambiguities in the relationship between age and the strength of the circulation. This paper presents a steady-state theory and a time-dependent extension to relate age of air directly to the diabatic circulation of the stratosphere. In steady state, it is the difference between the age of upwelling and downwelling air through an isentrope and not the absolute value of age that is a measure of the strength of the diabatic circulation through that isentrope. For the time-varying case, expressions for other terms that contribute to the age budget are derived. An idealized atmospheric general circulation model with and without a seasonal cycle is used to test the time-dependent theory and to find that these additional terms are small upon annual averaging. The steady-state theory holds as well for annual averages of a seasonally varying model as for a perpetual-solstice model. These results are a step toward using data to quantify the strength of the diabatic circulation.

On the Relationship between Deteriorated Level of ASR Damaged Concrete and Lithium Migration from Acceleration Lithium Migration Technique Test

2010 ◽  
Vol 163-167 ◽  
pp. 3812-3819
Author(s):  
Wei Chien Wang ◽  
Chih Chien Liu ◽  
Chau Lee
Keyword(s):  
Steady State ◽  
Linear Relationship ◽  
Current Density ◽  
Lithium Ion ◽  
Sodium Ion ◽  
Electrochemical Technique ◽  
The Relationship ◽  
Lithium Migration ◽  
Migration Technique

This research is to study the effect of deteriorated level on the ions migration in inhibiting the concrete damaged by ASR using electrochemical technique. Cylindrical concrete specimens made by reactive sandstone with 10 cm diameter and 5 cm height were prepared at the ages of 7, 14, 28, 90, and 180 days curing in a 38°C and 100% R.H. storage environment. The accelerated lithium migration technique (ALMT) was performed using LiOH H2O and Ca(OH)2 as electrolytes for anode and cathode, respectively. 9 A/m2 current density was used to drive lithium ion into and remove sodium ion out of the concrete. The results show that the rates of ions migration increase with increasing the deteriorated level of specimen. Furthermore, a linear relationship exists between the non-steady state migration coefficient of Li+ and the deteriorated level of specimen.

A Dynamic Model of a Locomotive Diesel Engine and Electrohydraulic Governor

1988 ◽  
Vol 110 (3) ◽  
pp. 405-414 ◽  
Author(s):  
C. I. Rackmil ◽  
P. N. Blumberg ◽  
D. A. Becker ◽  
R. R. Schuller ◽  
D. C. Garvey
Keyword(s):  
Steady State ◽  
Diesel Engine ◽  
Rate Of Change ◽  
Regression Equations ◽  
Detailed Model ◽  
Engine Simulation ◽  
System A ◽  
Load Demand ◽  
The Difference ◽  
Exhaust Energy

As part of a comprehensive simulation of a prototype locomotive propulsion system, a detailed model has been developed that predicts the dynamic response of an experimental two-stroke, turbocharged and intercooled diesel engine. Engine fueling and brake torque are computed from regression equations derived from an extensive data base. Corrections are applied to the calculated steady-state torque to account for dynamic deviations of in-cylinder trapped air-fuel ratio from the steady-state value. The engine simulation accurately represents the operation of the turbocharger, which is gear-driven at low turbocharger speeds, and freewheels through an overrunning clutch when exhaust energy accelerates the turbocharger beyond its geared speed. Engine fueling level, i.e., rack, is determined from a dynamic simulation of an electrohydraulic governor, which responds to the difference between the desired and the actual engine speeds. The governor representation includes: (1) finite rate of change of engine set speed; (2) load regulator feedback for control of applied engine loads; and (3) fuel limiting under conditions of excessively high load demand. The fundamentals of the engine/governor model are given in the paper along with examples that emphasize the dynamic operation of these particular components.

The Relationship between Speech Rate and Memory Span in Children

1994 ◽  
Vol 17 (1) ◽  
pp. 37-56 ◽  
Author(s):  
Lucy A. Henry
Keyword(s):  
Working Memory ◽  
Linear Relationship ◽  
Memory Span ◽  
Speech Rate ◽  
Individual Level ◽  
Word Length Effect ◽  
Children's Memory ◽  
The Difference ◽  
The Relationship ◽  
Working Memory Model

Evidence of a linear relationship between speech rate and memory span in children has been obtained in several studies (e.g. Hulme, Thomson, Muir, & Lawrence, 1984). This evidence is used to support an explanation of the development of memory span based on the working memory model (Baddeley, 1990). The model argues that speech rate is related to the amount recalled and that developmental increases in speech rate allow faster rehearsal with age and, hence, greater recall. However, the linear relationship between speech rate and memory span has generally been reported in terms of group means for speech rate and memory span rather than individual level correlations between the two variables. The present studies replicate the group relationship, but find that correlations between individual subject's speech rates and memory spans, when the effects of age are partialled out, are no longer significant. Nor was the size of the word length effect related to the difference in speech rate between short and long words. It is argued that the group mean relationship between speech rate and memory span is clear and replicable, but that the speech rates of individual children are not good predictors of those children's memory spans. The implications of these results for the working memory explanation of span development are discussed.

Log linear relationship between plasma arginine vasopressin and plasma osmolality.

1977 ◽  
Vol 233 (1) ◽  
pp. E37
Author(s):  
R E Weitzman ◽  
D A Fisher
Keyword(s):  
Steady State ◽  
Linear Relationship ◽  
Exponential Function ◽  
Arginine Vasopressin ◽  
Bolus Injection ◽  
Regression Line ◽  
Plasma Osmolality ◽  
Threshold Phenomenon ◽  
Plasma Arginine ◽  
Log Linear

The integrated plasma arginine vasopressin concentration (IpAVP) was determined by pooling the results of single samples collected every 3 min for 0.5 h in dehydrated, randomly hydrated, and water-loaded sheep. A linear relationship was observed between the log of the integrated AVP concentration and plasma osmolality. This relationship was tested by the bolus injection of 20 g/100 ml NaCl to both water-loaded and randomly hydrated sheep. The rise in the log of IpAVP divided by the rise in plasma osmolality was similar in both groups (P greater than 0.5) and was superimposable upon the regression line derived from steady-state observations. The data would suggest that AVP is released as an exponential function of plasma osmolality rather than as a threshold phenomenon.

Therapists' Expectancies and Patients' Improvement in Treatment: The Shape of the Link

1977 ◽  
Vol 40 (2) ◽  
pp. 443-453 ◽  
Author(s):  
Paul J. Martin ◽  
Marilynn L. Hunter ◽  
Kenneth E. Guhr ◽  
Nancey J. Acree
Keyword(s):  
Linear Relationship ◽  
Multiple Regression ◽  
Clinical Improvement ◽  
Empirical Support ◽  
Curvilinear Relationship ◽  
Regression Analyses ◽  
Significant Linear Relationship ◽  
Therapeutic Gain ◽  
The Relationship

It has been hypothesized that therapists' expectancies for therapeutic gain by their patients are linked to the actual clinical improvement shown by the patients during treatment. It has also been hypothesized that therapists' expectancies may help cause patients' improvement. The first hypothesis has received empirical support, but the second has not. The study reported here tested a causative interpretation of the link between therapists' expectancies and patients' improvement, and a second interpretation that therapists' expectancies predict but do not cause patients' improvement. Based on motivation research it was reasoned that a significant curvilinear relationship between therapists' expectancy and patients' improvement would support a causative interpretation; a significant linear relationship between these variables would support a predictive interpretation. Multiple regression analyses produced evidence of a significant linear relationship between measures of expectancy and improvement, but no curvilinear component to the relationship. The results are interpreted as supporting the predictive interpretation. Some limitations of the findings are discussed.

scholarly journals Age & Achievement

2004 ◽  
Vol 12 ◽  
pp. 49 ◽  
Author(s):  
James B. Grissom
Keyword(s):  
Linear Relationship ◽  
Educational Achievement ◽  
Negative Relationship ◽  
First Grade ◽  
Older Students ◽  
Transitional Kindergarten ◽  
Positive Linear Relationship ◽  
Grade Levels ◽  
The Difference ◽  
The Relationship

There is continuing controversy about the optimal or appropriate age at which children should start school. The purpose of this study is to examine the relationship between age and achievement. It is an attempt to evaluate the hypothesis that older students fare better academically than their younger classmates. Findings indicate that on average for students in elementary school there is positive linear relationship between age and achievement for age normal peers. Even though there is positive linear relationship, the difference in average test scores between the oldest and youngest students is not great and by the time students reach 10th grade the positive linear relationship has disappeared. For overage students there is on average a negative linear relationship between age and achievement at all grade levels. That is, the negative relationship between age and achievement remains constant over time. These results argue against modifying entrance age policies, delaying school entry, implementing transitional kindergarten or first grade programs or retaining students to improve educational achievement. Policies and practices that make students older than their classmates inversely affect their educational achievement.

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