scholarly journals Comparison of accuracy and precision of heart rate calibration methods to estimate total carbon dioxide production during 13C-breath tests

2005 ◽  
Vol 60 (1) ◽  
pp. 69-76 ◽  
Author(s):  
C Slater ◽  
T Preston ◽  
L T Weaver
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Carbon Dioxide Production ◽  
Total Carbon ◽  
Breath Tests ◽  
Accuracy And Precision ◽  
Calibration Methods

scholarly journals Using airborne HIAPER Pole-to-Pole Observations (HIPPO) to evaluate model and remote sensing estimates of atmospheric carbon dioxide

2016 ◽  
Author(s):  
C. Frankenberg ◽  
S. S. Kulawik ◽  
S. Wofsy ◽  
F. Chevallier ◽  
B. Daube ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Correlation Coefficients ◽  
Added Value ◽  
Total Carbon ◽  
Accuracy And Precision ◽  
Atmospheric Carbon ◽  
Carbon Dioxide Co2 ◽  
Global Carbon ◽  
Comparable Quality

Abstract. In recent years, space-borne observations of atmospheric carbon-dioxide (CO2) have become increasingly used in global carbon-cycle studies. In order to obtain added value from space-borne measurements, they have to suffice stringent accuracy and precision requirements, with the latter being less crucial as it can be reduced by just enhanced sample size. Validation of CO2 column averaged dry air mole fractions (XCO2) heavily relies on measurements of the Total Carbon Column Observing Network TCCON. Owing to the sparseness of the network and the requirements imposed on space-based measurements, independent additional validation is highly valuable. Here, we use observations from the HIAPER Pole-to-Pole Observations (HIPPO) flights from January 2009 through September 2011 to validate CO2 measurements from satellites (GOSAT, TES, AIRS) and atmospheric inversion models (CarbonTracker CT2013B, MACC v13r1). We find that the atmospheric models capture the XCO2 variability observed in HIPPO flights very well, with correlation coefficients (r2) of 0.93 and 0.95 for CT2013B and MACC, respectively. Some larger discrepancies can be observed in profile comparisons at higher latitudes, esp. at 300 hPa during the peaks of either carbon uptake or release. These deviations can be up to 4 ppm and hint at misrepresentation of vertical transport. Comparisons with the GOSAT satellite are of comparable quality, with an r2 of 0.85, a mean bias μ of −0.06 ppm and a standard deviation σ of 0.45 ppm. TES exhibits an r2 of 0.75, μ of 0.34 ppm and σ of 1.13 ppm. For AIRS, we find an r2 of 0.37, μ of 1.11 ppm and σ of 1.46 ppm, with latitude-dependent biases. For these comparisons at least 6, 20 and 50 atmospheric soundings have been averaged for GOSAT, TES and AIRS, respectively. Overall, we find that GOSAT soundings over the remote pacific ocean mostly meet the stringent accuracy requirements of about 0.5 ppm for space-based CO2 observations.

Combined heart rate and activity improve estimates of oxygen consumption and carbon dioxide production rates

1996 ◽  
Vol 81 (4) ◽  
pp. 1754-1761 ◽  
Author(s):  
Jon K. Moon ◽  
Nancy F. Butte
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Carbon Dioxide Production ◽  
Alternative Methods ◽  
Prediction Errors ◽  
Nonlinear Functions ◽  
Production Rates ◽  
Basal Energy Expenditure

Moon, Jon K., and Nancy F. Butte. Combined heart rate and activity improve estimates of oxygen consumption and carbon dioxide production rates. J. Appl. Physiol.81(4): 1754–1761, 1996.—Oxygen consumption (V˙o 2) and carbon dioxide production (V˙co 2) rates were measured by electronically recording heart rate (HR) and physical activity (PA). Mean daily V˙o 2 andV˙co 2 measurements by HR and PA were validated in adults ( n = 10 women and 10 men) with room calorimeters. Thirteen linear and nonlinear functions of HR alone and HR combined with PA were tested as models of 24-h V˙o 2 andV˙co 2. Mean sleepV˙o 2 andV˙co 2 were similar to basal metabolic rates and were accurately estimated from HR alone [respective mean errors were −0.2 ± 0.8 (SD) and −0.4 ± 0.6%]. The range of prediction errors for 24-h V˙o 2 andV˙co 2 was smallest for a model that used PA to assign HR for each minute to separate active and inactive curves (V˙o 2, −3.3 ± 3.5%; V˙co 2, −4.6 ± 3%). There were no significant correlations betweenV˙o 2 orV˙co 2 errors and subject age, weight, fat mass, ratio of daily to basal energy expenditure rate, or fitness. V˙o 2,V˙co 2, and energy expenditure recorded for 3 free-living days were 5.6 ± 0.9 ml ⋅ min−1 ⋅ kg−1, 4.7 ± 0.8 ml ⋅ min−1 ⋅ kg−1, and 7.8 ± 1.6 kJ/min, respectively. Combined HR and PA measured 24-h V˙o 2 andV˙co 2 with a precision similar to alternative methods.

scholarly journals Effects of Low Temperature and Freeze-Thaw Cycles on Hydrocarbon Biodegradation in Arctic Tundra Soil

2001 ◽  
Vol 67 (11) ◽  
pp. 5107-5112 ◽  
Author(s):  
Mikael Eriksson ◽  
Jong-Ok Ka ◽  
William W. Mohn
Keyword(s):  
Carbon Dioxide ◽  
Arctic Tundra ◽  
Carbon Dioxide Production ◽  
Additional Treatment ◽  
Total Carbon ◽  
Hydrocarbon Biodegradation ◽  
Tundra Soil ◽  
Spacer Length ◽  
Freeze Thaw ◽  
Arctic Tundra Soil

ABSTRACT Degradation of petroleum hydrocarbons was monitored in microcosms with diesel fuel-contaminated Arctic tundra soil incubated for 48 days at low temperatures (−5, 0, and 7°C). An additional treatment was incubation for alternating 24-h periods at 7 and −5°C. Hydrocarbons were biodegraded at or above 0°C, and freeze-thaw cycles may have actually stimulated hydrocarbon biodegradation. Total petroleum hydrocarbon (TPH) removal over 48 days in the 7, 0, and 7 and −5°C treatments, respectively, was 450, 300, and 600 μg/g of soil. No TPH removal was observed at −5°C. Total carbon dioxide production suggested that TPH removal was due to biological mineralization. Bacterial metabolic activity, indicated by RNA/DNA ratios, was higher in the middle of the experiment (day 21) than at the start, in agreement with measured hydrocarbon removal and carbon dioxide production activities. The total numbers of culturable heterotrophs and of hydrocarbon degraders did not change significantly over the 48 days of incubation in any of the treatments. At the end of the experiment, bacterial community structure, evaluated by ribosomal intergenic spacer length analysis, was very similar in all of the treatments but the alternating 7 and −5°C treatment.

scholarly journals Effects of Mentha Piperita Essential Oil Uptake or Inhalation on Heart Rate Variability and Cardiopulmonary Regulation during Exercise

2021 ◽  
Vol 10 (2) ◽  
pp. 65-72
Author(s):  
Tso-Yen Mao ◽  
◽  
Chun-Feng Huang ◽  
De-Yen Liu ◽  
Chien-Ting Chen ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Essential Oil ◽  
Respiratory Rate ◽  
Low Frequency ◽  
Carbon Dioxide Production ◽  
Mentha Piperita ◽  
Control Group ◽  
Frequency Area

This study compares the effects of the uptake or inhalation of 50uL Mentha piperita (MP) essential oil for 10 days on heart rate variability (HRV) and cardiopulmonary regulation during various exercise intensities. Forty-eight healthy male subjects were randomly assigned to MP uptake (MPU; n=16), MP inhalation (MPI; n=16), and control group (C; n=16). All participants were measured resting HRV, respiratory, cardiovascular, and metabolic parameters during aerobic, anaero- bic, and graded exercise tests (GXT) before and after treatment. There were significant increases in the low-frequency area (LFa; 1.8±0.1 vs 2.2±0.2 ms²), the ratio of low frequency to respiration frequency area (LFa/RFa; 0.9±0.1 vs 1.3±0.1) at resting and carbon dioxide production (VCO 2 ; 41.2±4.0 vs 49.2±6.8 mL/min -1 /kg -1 ), ventilation per minute (V E ; 80.2±4.3 vs 97.5±5.5 L/min -1 ), and respiratory rate (RR; 38.2±1.9 to 44.3±2.1 breath/min -1 ) in an anaerobic test following MPU inter- vention. In GXT, maximal carbon dioxide production (VCO 2max; 51.9±3.5 to 59.1±6.4 mL/min -1 /kg -1 ), maximal ventilation per minute (V Emax ; 126.4±6.5 to 138.4±5.4 L/min -1 ) and maximal respiratory rate (RR max ; 52.7±3.6 to 60.1±2.3 breath/min -1 ) significantly increased in MPU. The correlations of ΔLFa with ΔVCO 2max , ΔV Emax , and ΔRR max in the MPU group were signifi- cant. Continuous uptake or inhalation of 50uL MP oil for 10 days does not improve aerobic capacity and maximal exercise performance, but 10 days’ uptake of MP essential oil increased sympathetic activity at rest and may relate to respiratory regulation under high-intensity exercise.

Measurement of Total Carbon Dioxide Production by Means of D2O18

1955 ◽  
Vol 7 (6) ◽  
pp. 704-710 ◽  
Author(s):  
Nathan Lifson ◽  
George B. Gordon ◽  
Ruth McClintock
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Production ◽  
Total Carbon

Maros-Schulek Technique for Measurement of Carbon Dioxide Production in Fish and Respiratory Quotient in Tilapia mossambica

1971 ◽  
Vol 28 (9) ◽  
pp. 1342-1344 ◽  
Author(s):  
M. N. Kutty ◽  
N. V. Karuppannan ◽  
M. Narayanan ◽  
M. Peer Mohamed
Keyword(s):  
Carbon Dioxide ◽  
Respiratory Quotient ◽  
Anal Chim ◽  
Carbon Dioxide Production ◽  
Total Carbon ◽  
Small Samples ◽  
Aquatic Animals ◽  
Large Samples ◽  
Tilapia Mossambica ◽  
Present Technique

The technique used by Maros et al. (Anal. Chim. Acta 25: 390–399, 1961) for accurate measurements of total carbon dioxide in small samples has been modified for large samples of water, enabling measurement of carbon dioxide production by small aquatic animals. Data obtained from Tilapia mossambica by using the present technique are discussed. The method is considered to be adequate for obtaining reliable estimates of carbon dioxide production in fish.

scholarly journals Inhaled Hydrogen Sulfide

2008 ◽  
Vol 108 (4) ◽  
pp. 659-668 ◽  
Author(s):  
Gian Paolo Volpato ◽  
Robert Searles ◽  
Binglan Yu ◽  
Marielle Scherrer-Crosbie ◽  
Kenneth D. Bloch ◽  
...  
Keyword(s):  
Physical Activity ◽  
Carbon Dioxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Body Temperature ◽  
Ambient Temperature ◽  
Cardiovascular Function ◽  
Carbon Dioxide Production ◽  
The Impact

Background Breathing hydrogen sulfide (H2S) has been reported to induce a suspended animation-like state with hypothermia and a concomitant metabolic reduction in rodents. However, the impact of H2S breathing on cardiovascular function remains incompletely understood. In this study, the authors investigated the cardiovascular and metabolic effects of inhaled H2S in a murine model. Methods The impact of breathing H2S on cardiovascular function was examined using telemetry and echocardiography in awake mice. The effects of breathing H2S on carbon dioxide production and oxygen consumption were measured at room temperature and in a warmed environment. Results Breathing H2S at 80 parts per million by volume at 27 degrees C ambient temperature for 6 h markedly reduced heart rate, core body temperature, respiratory rate, and physical activity, whereas blood pressure remained unchanged. Echocardiography demonstrated that H2S exposure decreased both heart rate and cardiac output but preserved stroke volume. Breathing H2S for 6 h at 35 degrees C ambient temperature (to prevent hypothermia) decreased heart rate, physical activity, respiratory rate, and cardiac output without altering stroke volume or body temperature. H2S breathing seems to induce bradycardia by depressing sinus node activity. Breathing H2S for 30 min decreased whole body oxygen consumption and carbon dioxide production at either 27 degrees or 35 degrees C ambient temperature. Both parameters returned to baseline levels within 10 min after the cessation of H2S breathing. Conclusions Inhalation of H2S at either 27 degrees or 35 degrees C reversibly depresses cardiovascular function without changing blood pressure in mice. Breathing H2S also induces a rapidly reversible reduction of metabolic rate at either body temperature.

Nitric oxide response in exhaled air during an incremental exhaustive exercise

1997 ◽  
Vol 82 (4) ◽  
pp. 1311-1318 ◽  
Author(s):  
M. F. Chirpaz-Oddou ◽  
A. Favre-Juvin ◽  
P. Flore ◽  
J. Eterradossi ◽  
M. Delaire ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Heart Rate ◽  
Exercise Intensity ◽  
Minute Ventilation ◽  
Carbon Dioxide Production ◽  
Exhaustive Exercise ◽  
Mean Values ◽  
Exhaled Air ◽  
Sedentary Women

Chirpaz-Oddou, M. F., A. Favre-Juvin, P. Flore, J. Eterradossi, M. Delaire, F. Grimbert, and A. Therminarias. Nitric oxide response in exhaled air during an incremental exhaustive exercise. J. Appl. Physiol. 82(4): 1311–1318, 1997.—This study examines the response of the exhaled nitric oxide (NO) concentration (Cno) and the exhaled NO output (V˙no) during incremental exercise and during recovery in six sedentary women, seven sedentary men, and eight trained men. The protocol consisted of increasing the exercise intensity by 30 W every 3 min until exhaustion, followed by 5 min of recovery. Minute ventilation (V˙e), oxygen consumption (V˙o 2), carbon dioxide production, heart rate, Cno, andV˙nowere measured continuously. The Cno in exhaled air decreased significantly provided that the exercise intensity exceeded 65% of the peak V˙o 2. It reached similar values, at exhaustion, in all three groups. TheV˙no increased proportionally with exercise intensity up to exhaustion and decreased rapidly during recovery. At exhaustion, the mean values were significantly higher for trained men than for sedentary men and sedentary women. During exercise,V˙nocorrelates well with V˙o 2, carbon dioxide production, V˙e, and heart rate. For the same submaximal intensity, and thus a givenV˙o 2 and probably a similar cardiac output,V˙no appeared to be similar in all three groups, even if theV˙e was different. These results suggest that, during exercise,V˙no is mainly related to the magnitude of aerobic metabolism and that this relationship is not affected by gender differences or by noticeable differences in the level of physical training.

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