Symbolic Equation for the Instantaneous Amount of Substance in Linear Compartmental Systems

2011 ◽  
pp. 348-379
Author(s):  
J.M. Villalba ◽  
R. Varón ◽  
E. Arribas ◽  
R. Diaz-Sierra ◽  
F. Garcia-Sevilla ◽  
...  
Keyword(s):  
Time Course ◽  
Open Systems ◽  
Residence Times ◽  
Transient Phase ◽  
State Equations ◽  
Amount Of Substance ◽  
The Mean ◽  
Symbolic Equation ◽  
Mean Residence Times ◽  
User Friendly

The symbolic time course equations corresponding to a general model of a linear compartmental system, closed or open, with or without traps and with zero input are presented in this chapter. From here, the steady state equations are obtained easily from the transient phase equations by setting the time towards infinite. Special attention is given to the open systems, for which an exhaustive kinetic analysis has been developed to obtain important properties. Besides, the results are particularized to open systems without traps. The software COEFICOM, easy to use and with a user-friendly format of the input of data and the output of results, allows the user to obtain the symbolic expressions of the coefficients involved in the general symbolic equation and all the information necessary to derive the symbolic time course equations for closed or open systems as well as for the derivation of the mean residence times.

scholarly journals Pharmacokinetics and tissue residue of toltrazuril in broiler chickens

2015 ◽  
Vol 4 (3) ◽  
pp. 310 ◽  
Author(s):  
Ahmed Soliman
Keyword(s):  
Broiler Chickens ◽  
Animal Health ◽  
Tissue Level ◽  
Residence Times ◽  
Once Daily ◽  
Tissue Residue ◽  
Elimination Half ◽  
The Mean ◽  
Mean Residence Times ◽  
Broiler Feed

<p>The pharmacokinetics and tissue residue of toltrazuril (Baycox<sup>®</sup>, Bayer Animal Health) were investigated in broiler chickens after repeated oral administrations of 7 mg/kg b.wt once daily for two consecutive days. Chickens were subjected to clinical diagnosis to ensure that each one is free from any Eimeria was received a standard broiler feed free from any medications. The results revealed that following repeated oral administration; toltrazuril peaked in blood with [C<sub>max</sub>] of 6.56 and 6.70 μg/ml at [T<sub>max</sub>] of 2.56 and 2.52 hours and the elimination half-life [t<sub>1/2β</sub>] of 14.92 and 16.19 hours and the mean residence times (MRT) were 21.33 and 23.14 hours after first and second doses, respectively. The tissue level concentrations were highest in the kidney and decreased in the following order: liver &gt; lung &gt; heart &gt; muscle &gt; skin and fat. No toltrazuril residues were detected in tissues and plasma after 8 days.</p>

Environmental tritium measurements and lumped parameter modelling in the Tafilalet aquifer, south-east Morocco

2007 ◽  
Vol 95 (10) ◽  
Author(s):  
S. Bouhlassa ◽  
B. Ammary ◽  
A. Elyahyaoui
Keyword(s):  
Residence Time ◽  
Subsurface Water ◽  
Residence Times ◽  
Transport Modelling ◽  
Lumped Parameter ◽  
The Mean ◽  
Mean Residence Times ◽  
Environmental Tritium ◽  
Future Work

The paper presents a case study for the application of environmental tritium to assess the mean residence time of water in the Tafilalet aquifer. This aquifer corresponds geologically to a tectonic depression with Quaternary fill. The Tafilalet area depends mainly on agriculture and herding. Groundwater is the main source of water supply for domestic, agriculture, and herding purposes.The data on the distribution of tritium in subsurface water indicate the modern water of the Tafilalet aquifer. The tritium transport modelling indicates that Quaternary alluvial waters are likely to have short mean residence times of a few years (14 to 32 years). The study addresses several difficulties concerning the detailed quantitative interpretations of the results, which must be the focus of future work.

EARLY VARIATIONS OF PLASMA CORTISOL AFTER PULSE INTRAVENOUS INJECTION OF DIBUTYRYL CYCLIC ADENOSINE 3′,5′-MONOPHOSPHATE IN NORMAL SUBJECTS

1973 ◽  
Vol 72 (4) ◽  
pp. 753-761 ◽  
Author(s):  
Alberto Angeli ◽  
Giuseppe Boccuzzi ◽  
Roberto Frajria ◽  
Daniela Bisbocci ◽  
Franco Ceresa
Keyword(s):  
Intravenous Injection ◽  
Plasma Cortisol ◽  
Time Course ◽  
Healthy Adult ◽  
Normal Subjects ◽  
Adult Women ◽  
Healthy Women ◽  
Adrenal Steroidogenesis ◽  
The Mean ◽  
Zero Time

ABSTRACT 10 mg/kg of dibutyryl cyclic adenosine 3′,5′-monophosphate (Db-cAMP) was iv pulse injected into twelve healthy adult women. The plasma cortisol levels were determined as 11-OHCS at zero time and then at 2.5, 5, 7.5, 10, 15, 30, 60 and 180 min after the injection. The data were compared with those obtained at the corresponding times in two groups of eleven and seventeen healthy women after the injection of 250 ng and 250 μg of synthetic β-1-24 corticotrophin performed in the same manner as the injection of the nucleotide. The mean increments in plasma cortisol were significantly lower after Db-cAMP than after ACTH. Differences were noted by analyzing the time course of the responses. In the case of stimulation with Db-cAMP the 11-OHCS levels rose progressively to a maximum at 15–30 min. By contrast, a peak of plasma cortisol was evident in most cases within a few min after the injection of ACTH; after a fall, a later rise was then observed starting from 15 min. The differences in the plasma 11-OHCS responses after the two stimuli may also be of interest clinically for the investigation of some aspects of adrenal steroidogenesis.

Quantitative studies of the reactions to horizontal angular accelerations in axolotls. I. The head-turning reflexes of normal animals

1977 ◽  
Vol 66 (1) ◽  
pp. 1-14
Author(s):  
K. Brandle
Keyword(s):  
Stimulus Intensity ◽  
Time Course ◽  
Maximum Velocity ◽  
Afferent Input ◽  
Head Turning ◽  
Mean Values ◽  
Quantitative Studies ◽  
The Mean ◽  
Negative Exponential ◽  
Total Angle

1. Artifically metamorphosed axolotls were exposed to both brief (impulse) and long-lasting horizontal angular accelerations on a turn-table. The animals responded with a head-turning reaction. 2. The general course of the reaction to impulse acceleration was independent of stimulus intensity. The velocity of the head movement first increased to a maximum exponentially and then decreased in a negative exponential manner. Stimulus intensity had a linear relationship to the mean maximum velocity and mean total angle covered by head-turning. The average velocity-time curves at various stimulus intensities differed only by a velocity factor. 3. During long-lasting constant accelerations the velocity of the head-turning increased to a maximum velocity in a sigmoid time-course and then decreased, first to a constant velocity, and then further. Mean values of the maximum velocity were correlated linearly with the stimulus intensity. 4. It was concluded that the head-turning reflexes in axolotls do not agree with the accepted movements of the vertebrate cupula and therefore are not a simple ‘copy’ of the afferent input. It is also suggested that the reaction threshold differes from that for the labyrinthine input.

Biosurfactant production and its effects on solubilization activity of phenanthrene: a longitudinal study

2016 ◽  
Vol 74 (3) ◽  
pp. 580-585
Author(s):  
Masoumeh Golshan ◽  
Maryam Dastoorpour ◽  
Roshanak Rezaei Kalantary
Keyword(s):  
Time Course ◽  
Inoculum Size ◽  
Biosurfactant Production ◽  
Practical Application ◽  
Time Intervals ◽  
Initial Inoculum ◽  
Bacterial Inoculum ◽  
Polycyclic Aromatic ◽  
The Mean ◽  
Time Course Study

Pseudomonas facilis and Pseudomonasspp., isolated on the basis of its ability to grow on polycyclic aromatic hydrocarbon, was assayed for biosurfactant production (BP) potentials by measuring the surface tension (ST) of the culture supernatant at different time intervals. The strains in three levels of initial inoculum size (OD600 nm = 0.5, 1, 1.5) were added to medium to determine if bacterial inoculum size affects solubilization of phenanthrene (PHE).The result showed that although the two strains reduced the mean ST to less than 34.12 mN m−1 at the end of day 6, mean solubilization activity of PHE reached 77.05 mg L−1 on the sixth day. There was a significant increase in BP over time (P = 0.008); reaching its peak, 157.84 mg L−1, at the end of the sixth day. Mean solubilization activity of PHE was not significantly different for the two strains (P = 0.216). The time-course study revealed that the ST reduction and BP potential was enhanced as inoculation size increased, leading to higher PHE solubility during the incubation time. However, the trend of increase in PHE solubility was not totally in the same way to cell growth and BP. It may be suggested that more bacterial density needs to be inoculated for practical application of effective bioremediation.

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