scholarly journals An Improved Apparatus for the Determination of Carbon Dioxide Production in Physiological Plant Studies

1935 ◽  
Vol 22 (2) ◽  
pp. 361 ◽  
Author(s):  
F. Lyle Wynd
1995 ◽  
Vol 198 (1) ◽  
pp. 213-219 ◽  
Author(s):  
G Walsberg ◽  
B Wolf

Determination of animal power consumption by indirect calorimetry relies upon accurate estimation of the thermal equivalent of oxygen consumed or carbon dioxide produced. This estimate is typically based upon measurement or assumption of the respiratory quotient (RQ), the ratio of CO2 produced to O2 consumed. This ratio is used to indicate the mixture of lipids, carbohydrates and proteins in the metabolic substrate. In this analysis, we report the RQ for two bird species, Passer domesticus and Auriparus flaviceps, under several dietary and fasting regimes. RQ commonly differed substantially from those typically assumed in studies of energy metabolism and often included values below those explainable by current knowledge. Errors that could result from these unexpected RQ values can be large and could present the primary limit to the accuracy of power consumption estimates based upon measurement of carbon dioxide production.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Mohamed Samir Abdelghafar ◽  
Zahretelwady Mohamed Salaheldin Mohamed

The Analyst ◽  
2018 ◽  
Vol 143 (4) ◽  
pp. 956-962 ◽  
Author(s):  
M. Rizwan Ahmed ◽  
Sean McSweeney ◽  
Jacob Krüse ◽  
Bastiaan Vos ◽  
Dara Fitzpatrick

Carbon dioxide production due to an acid–base reaction.


2012 ◽  
Vol 9 (7) ◽  
pp. 1009-1011 ◽  
Author(s):  
Christopher Reiff ◽  
Kara Marlatt ◽  
Donald R. Dengel

Background:Traditional desks require students to sit; however, recently schools have provided students with nontraditional standing desks. The purpose of this study was to investigate differences in caloric expenditure of young adults while sitting at a standard classroom desk and standing at a nontraditional standing classroom desk.Methods:Twenty (10 male/10 female) young (22.8 ± 1.9 y), healthy participants reported to the laboratory between the hours of 7:00 AM and 2:00 PM following a 12-h fast and 48-h break in exercise. Participants were randomly assigned to perform a series of mathematical problems either sitting at a normal classroom desk or standing at a nontraditional standing desk. Inspired and expired gases were collected for 45-min for the determination of oxygen consumption (VO2), carbon dioxide production (VCO2), and minute ventilation (VE) using a metabolic gas system.Results:There were significant increases from sitting to standing in VO2 (0.22 ± 0.05 vs. 0.28 ± 0.05 L·min−1, P ≤ .0001), VCO2 (0.18 ± 0.05 vs. 0.24 ± 0.050 L·min−1, P ≤ .0001), VE (7.72 ± 0.67 vs. 9.41 ± 1.20 L·min−1, P ≤ .0001), and kilocalories expended per minute (1.36 ± 0.20 kcal/ min, P ≤ .0001 vs. 1.02 ± 0.22 kcal/min, P ≤ .0001).Conclusions:Results indicate a significant increase in caloric expenditure in subjects that were standing at a standing classroom desk compared with sitting at a standard classroom desk.


1923 ◽  
Vol 21 (4) ◽  
pp. 440-450 ◽  
Author(s):  
Major Greenwood ◽  
Ethel M. Newbold

Towards the close of the Great War, when economy of food consumption was an urgent necessity, considerable attention was paid to the determination of the energetic needs of various kinds of muscular work. The majority of scientific papers then published dealt with the problem.


1935 ◽  
Vol 117 (806) ◽  
pp. 483-504 ◽  

There is much evidence to show that under normal circumstances the respiration of higher plants involves the oxidative breakdown of hexose carbohydrate. During leaf starvation under carefully controlled external conditions, a gradual exhaustion of the carbohydrate substrate is, therefore, one of the important internal changes likely to affect the rate of carbon-dioxide production. The researches to be described here, and in a subsequent paper, were planned in order to test this possibility; an attempt has been made to discover the relation between the con­centration of readily available carbohydrate and the rate of carbon-dioxide production in starving leaves. The chief experimental difficulty involved was that of making accurate determinations of the various hexose sources present in the leaf, and methods whereby this could be done were tested extensively. Since the validity of many of the conclusions reached depends primarily on the accuracy of the analytical methods, it was considered important that an account of these should be included here. It is with this phase of the problem that the present paper is concerned.


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