scholarly journals Determination of individual stimulus-response curves in the visual cortex

2002 ◽  
Vol 17 (4) ◽  
pp. 244-250 ◽  
Author(s):  
Rogier E. Hagenbeek ◽  
Serge A.R.B. Rombouts ◽  
Bob W. van Dijk ◽  
Frederik Barkhof
Keyword(s):  
Visual Cortex ◽  
Response Curves ◽  
Individual Stimulus ◽  
Stimulus Response

scholarly journals Mechanosensitive hyaluronan secretion: stimulus-response curves and role of transcription-translation-translocation in rabbit joints

2009 ◽  
Vol 94 (3) ◽  
pp. 350-361 ◽  
Author(s):  
A. K. T. Wann ◽  
K. R. Ingram ◽  
P. J. Coleman ◽  
N. McHale ◽  
J. R. Levick
Keyword(s):  
Response Curves ◽  
Stimulus Response

scholarly journals Analysis and Design of Stimulus Response Curves of E. coli

Metabolites ◽  
2012 ◽  
Vol 2 (4) ◽  
pp. 844-871
Author(s):  
Andreas Kremling ◽  
Anna Goehler ◽  
Knut Jahreis ◽  
Markus Nees ◽  
Benedikt Auerbach ◽  
...  
Keyword(s):  
Response Curves ◽  
Analysis And Design ◽  
E Coli ◽  
Stimulus Response

Inhibition of nitric oxide synthesis attenuates thermally induced asthma

2001 ◽  
Vol 91 (2) ◽  
pp. 703-708 ◽  
Author(s):  
C. Kotaru ◽  
M. Skowronski ◽  
A. Coreno ◽  
E. R. McFadden
Keyword(s):  
Nitric Oxide ◽  
Minute Ventilation ◽  
Isotonic Saline ◽  
Forced Expiratory Volume ◽  
Response Curves ◽  
Thermally Induced ◽  
Stimulus Response ◽  
Fractional Concentration ◽  
Exhaled Air ◽  
The Right

To determine whether the inhibition of nitric oxide (NO) synthesis attenuates thermally induced obstruction, we had 10 asthmatic volunteers perform isocapnic hyperventilation with frigid air after inhaling 1 mg of N G-monomethyl-l-arginine (l-NMMA) or isotonic saline in a blinded fashion. The challenges were identical in all respects, and there were no differences in baseline lung function [1-s forced expiratory volume (FEV1); saline 2.8 ± 0.3 liters, l-NMMA 2.9 ± 0.3 liters; P = 0.41] or prechallenge fractional concentration of nitric oxide in the exhaled air (FeNO) [saline 23 ± 6 parts/billion (ppb),l-NMMA 18 ± 4 ppb; P = 0.51]. Neither treatment had any impact on the FEV1, pulse, or blood pressure. After l-NMMA, FeNO fell significantly ( P < 0.0001), the stimulus-response curves shifted to the right, and the minute ventilation required to reduce the FEV1 20% rose 53.5% over control ( P = 0.02). The results of this study demonstrate that NO generated from the airways of asthmatic individuals may play an important role in the pathogenesis of thermally induced asthma.

XVII.—Utilization of Dietary Purines and Pyrimidines by Drosophila melanogaster

1957 ◽  
Vol 66 (4) ◽  
pp. 339-359 ◽  
Author(s):  
James H. Sang
Keyword(s):  
Drosophila Melanogaster ◽  
Orotic Acid ◽  
De Novo ◽  
Normal Growth ◽  
Energy Utilization ◽  
Good Growth ◽  
Response Curves ◽  
Adenylic Acid ◽  
Multicellular Organisms

SynopsisDrosophila melanogaster larvæ when cultured aseptically on a synthetic diet require exogenous ribose nucleic acid (RNA) for normal growth even though they can synthesize their own endogenous RNA from simple precursors. The optimum dietary supply lies between 0.4 and 0.7 per cent RNA. Individual bases, nucleosides and nucleotides which make up RNA cannot substitute for the whole polynucleotide, but adenine, adenosine, adenylic acid, guanosine and guanylic acid are used and stimulate growth to varying degrees. The pyrimidines and their nucleosides and nucleotides are not used when fed singly.It is shown that the de novo synthesis of purines may be more difficult than that of pyrimidines, and that if a source of purines is supplied (as adenylic acid), then the nucleosides and nucleotides of both cytosine and uracil are utilized by the larvæ, whereas the free bases are not. Cytidylic and uridylic acids seem to be interchangeable, and together with an adequate supply of adenylic acid give as good growth as RNA. Orotic acid and 2—6-diaminopurine are not used by the larvæ under the conditions described, but hypoxanthine and inosine are: xanthine and xanthosine can also be shown to have an effect on growth.Dose-response curves were determined for adenylic, guanylic, cytidylic and uridylic acids under conditions which allow the determination of the optimal supplies of each. These are found to be about 0.110, 0.080, 0.025 and 0.025 per cent, respectively. The requirement of RNA is therefore primarily a requirement of adenylic acid, since more than enough of the other nucleotides should be available when the supply of RNA is optimal. The optimal supply of adenine corresponds almost exactly with the optimal supply of adenylic acid, though a somewhat delayed larval development may be a result of energy utilization in the base-nucleoside-nucleotide conversion.These results are discussed in the light of our knowledge of purine and pyrimidine utilization in other multicellular organisms, particularly the rat, and possible applications of the findings are considered.

Determination of the Fluid-Elastic Stability Threshold in the Presence of Turbulence: A Theoretical Study

1989 ◽  
Vol 111 (4) ◽  
pp. 407-419 ◽  
Author(s):  
J. H. Lever ◽  
G. Rzentkowski
Keyword(s):  
Theoretical Study ◽  
Cross Flow ◽  
Elastic Stability ◽  
Mass Ratio ◽  
Response Curves ◽  
Stability Threshold ◽  
Pitch Ratio ◽  
The Stability ◽  
Experimental Findings

A model has been developed to examine the effect of the superposition of turbulent buffeting and fluid-elastic excitation on the response of a single flexible tube in an array exposed to cross-flow. The modeled response curves for a 1.375-pitch ratio parallel triangular array are compared with corresponding experimental data for the same array; reasonably good qualitative agreement is seen. Turbulence is shown to have a significant effect on the determination of the stability threshold for the array, with increasing turbulent buffeting causing a reduction in the apparent critical velocity. The dependence of turbulence response on mass ratio is also found to yield a slight independence between mass and damping parameters on stability threshold estimates, which may account for similar experimental findings. Different stability criteria are compared, and an attempt is made to provide some guidance in the interpretation of response curves from actual tests.

Tachykinins mediate bronchoconstriction elicited by isocapnic hyperpnea in guinea pigs

1989 ◽  
Vol 66 (3) ◽  
pp. 1108-1112 ◽  
Author(s):  
D. W. Ray ◽  
C. Hernandez ◽  
A. R. Leff ◽  
J. M. Drazen ◽  
J. Solway
Keyword(s):  
Tidal Volume ◽  
Guinea Pigs ◽  
Minute Ventilation ◽  
Response Curves ◽  
Mechanically Ventilated ◽  
Stimulus Response ◽  
Respiratory System Resistance ◽  
Water Saturated ◽  
And Control ◽  
Isocapnic Hyperpnea

We tested the hypothesis that tachykinins mediate hyperpnea-induced bronchoconstriction (HIB) in 28 guinea pigs. Stimulus-response curves to increasing minute ventilation with dry gas were generated in animals depleted of tachykinins by capsaicin pretreatment and in animals pretreated with phosphoramidon, a neutral metalloendopeptidase inhibitor. Sixteen anesthetized guinea pigs received capsaicin (50 mg/kg sc) after aminophylline (10 mg/kg ip) and terbutaline (0.1 mg/kg sc). An additional 12 animals received saline (1 ml sc) instead of capsaicin. One week later, all animals were anesthetized, given propranolol (1 mg/kg iv), and mechanically ventilated (6 ml/kg, 60 breaths/min, 50% O2 in air fully water saturated). Phosphoramidon (0.5 mg iv) was administered to five of the noncapsaicin-treated guinea pigs. Eucapnic dry gas (95% O2–5% CO2) hyperpnea “challenges” were performed by increasing the tidal volume (2–6 ml) and frequency (150 breaths/min) for 5 min. Capsaicin-pretreated animals showed marked attenuation in HIB, with a rightward shift of the stimulus-response curve compared with controls; the estimated tidal volume required to elicit a twofold increase in respiratory system resistance (ES200) was 5.0 ml for capsaicin-pretreated animals vs. 3.7 ml for controls (P less than 0.03). Phosphoramidon-treated animals were more reactive to dry gas hyperpnea compared with control (ES200 = 2.6 ml; P less than 0.0001). Methacholine dose-response curves (10(-11) to 10(-7) mol iv) obtained at the conclusion of the experiments were similar among capsaicin, phosphoramidon, and control groups. These findings implicate tachykinin release as an important mechanism of HIB in guinea pigs.

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