QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online March 14, 2005
Journal of Experimental Biology 208, 1035-1043 (2005)
Published by The Company of Biologists 2005
doi: 10.1242/jeb.01477

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Walsberg, G. E. Articles by Hoffman, T. C.M. Search for Related Content PubMed PubMed Citation Articles by Walsberg, G. E. Articles by Hoffman, T. C.M.

Direct calorimetry reveals large errors in respirometric estimates of energy expenditure

Glenn E. Walsberg^* and Ty C.M. Hoffman

School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA

View larger version (25K): [in a new window]   Fig. 1. Rate of oxygen consumption during 17 h after removal from food. Values are means ± 95% confidence intervals; N=10 for each species.

View larger version (25K): [in a new window]   Fig. 2. Rate of carbon dioxide production during 17 h after removal from food. Values are means ± 95% confidence intervals; N=10 for each species.

View larger version (24K): [in a new window]   Fig. 3. Metabolic heat production measured by direct calorimetry during 17 h after removal from food. Values are means ± 95% confidence intervals; N=10 for each species.

View larger version (26K): [in a new window]   Fig. 4. Respiratory exchange ratios during 17 h after removal from food. Values are means ± 95% confidence intervals; N=10 for each species. Broken lines indicate expected maximum and minimum values.

View larger version (26K): [in a new window]   Fig. 5. Thermal equivalents of oxygen consumption during 17 h after removal from food. Values are means ± 95% confidence intervals; N=10 for each species. Broken lines represent the expected maximum and minimum values (Table 1).

View larger version (28K): [in a new window]   Fig. 6. Thermal equivalents of carbon dioxide production during 17 h after removal from food. Values are means ± 95% confidence intervals; N=10 for each species. Broken lines represent the expected maximum and minimum values (Table 1).

View larger version (25K): [in a new window]   Fig. 7. Mean absolute error in estimates of the thermal equivalent of either CO2 production or O2 consumption produced by assuming that protein is conserved and using the respiratory exchange ratio to estimate the fractional content of lipids and carbohydrates in the catabolic substrate. Filled circles indicate N=10. Unfilled circles indicate that sample size was reduced below 10 because RER values outside of the range of 0.71-1.00 did not allow estimation of thermal equivalents for some individuals.

View larger version (32K): [in a new window]   Fig. 8. Mean absolute error in estimates of the thermal equivalent of CO2 production and O2 consumption by measuring either gas and assuming that the animal is catabolizing lipids. N=10 for each species.