Blood gas transport and oxygen consumption in a supralittoral crab, Leptograpsus variegatus (Crustacea: Brachyura)

1992 ◽  
Vol 43 (6) ◽  
pp. 1573 ◽  
Author(s):  
P Greenaway ◽  
S Morris ◽  
N Sanders ◽  
A Adamczewska
Keyword(s):  
Oxygen Consumption ◽  
Body Size ◽  
Temperature Sensitivity ◽  
Oxygen Transport ◽  
Anaerobic Exercise ◽  
Blood Gas ◽  
Exhausting Exercise ◽  
Exercise Period ◽  
Bohr Factor ◽  
Total Body

Routine oxygen consumption of Leptograpsus variegatus in air (MO2=6.12 mass (g)0.854 �mol h-1) was elevated from three to six times (depending on body size) following exhausting exercise (MO2= 42.8 mass0.608 �mol h-1). In addition, considerable capacity for anaerobic exercise was apparent and total body L-lactate rose 4.8 times during the exercise period (25-g crab). The respiratory pigment (haemocyanin) had a low affinity under normoxic resting conditions (P50=25 Torr, where 1 Torr = 101 325/760 Pa) but showed a large Bohr effect (Bohr factor = -0.78), a marked temperature sensitivity (ΔH= 67.4 kJ mol-1), and a large potentiating effect by L-lactate (lactate coefficient = - 0.205). These features are more characteristic of the haemocyanin of aquatic crustaceans than those of terrestrial crustaceans. The affinity of the haemocyanin of L. variegatus was also decreased by elevated PCO2. Haemocyanin was responsible for 92% of oxygen transport in both resting and exercised crabs. These features are discussed in relation to the degree of adaptation of L. variegatus to a terrestrial lifestyle.

Effect of measurement error on calculated variables of oxygen transport

1996 ◽  
Vol 80 (2) ◽  
pp. 559-563 ◽  
Author(s):  
R. P. Woda ◽  
R. D. Dzwonczyk ◽  
J. P. Orlowski ◽  
F. Van Lente ◽  
L. A. Lynn
Keyword(s):  
Oxygen Consumption ◽  
Measurement Error ◽  
Oxygen Transport ◽  
Venous Blood ◽  
Intraclass Correlation ◽  
Mixed Venous Blood ◽  
Blood Gas ◽  
Percent Error ◽  
Error Amplification ◽  
Mixed Venous

The effect of measurement error in pH, PCO2, and PO2 on mathematically derived variables of oxygen transport in patients was delineated by comparing calculated oxygen saturations from a blood-gas machine with measured saturations from a CO-oximeter and further by modeling the error in a computer simulation. Twenty-one critically ill patients aged 30-84 yr were studied. A total of 80 arterial and 80 mixed venous blood gas samples were collected. The intraclass correlation results between measured and calculated arterial (SaO2) and mixed venous (Sv-O2) oxygen saturations were 0.59 and 0.68, respectively. The product-moment correlation for SaO2 was 0.75 and for Sv-O2 was 0.77. The percent error in calculating and measuring oxygen saturation was found to be greater at low PO2 values, whereas percent error of calculating oxygen consumption increased as the PO2 increased. Measurement repeatability at high PO2 is better than at low PO2 for both measured and calculated methods. We conclude from this comparison that measured and calculated SaO2 and Sv-O2 values are not interchangeable. Each can introduce substantial error in calculating oxygen consumption through error propagation and error amplification.

Characterisation of production of organic rich topsoil from sludge

2000 ◽  
Vol 42 (9) ◽  
pp. 195-201 ◽  
Author(s):  
P. Andreasen ◽  
P. B. Mortensen ◽  
A. Stubsgaard ◽  
B. Langdahl
Keyword(s):  
Organic Matter ◽  
Oxygen Consumption ◽  
Oxygen Transport ◽  
Mineral Soil ◽  
Climatic Conditions ◽  
Growth Media ◽  
Soil Mixture ◽  
Water Suspension ◽  
Aerobic Process ◽  
Stable Product

The stabilisation of a sludge-mineral soil mixture and a method to evaluate the state of stabilisation were investigated. The organic matter and nitrogen content are reduced up to 50% during a stabilisation process of three months under Danish climatic conditions. The stabilisation was shown to be an aerobic process limited by oxygen transport within the mixture. The degree of stabilisation was evaluated by oxygen consumption in a water suspension and the results showed that a stable product was achieved when oxygen consumption was stable and in the level of natural occurring aerobic soils (0.1 mgO2/(g DS*hr). The study thereby demonstrates that a stability of a growth media can be controlled by the oxygen consumption method tested.

scholarly journals Effects of face masks on performance and cardiorespiratory response in well-trained athletes

2021 ◽  
Author(s):  
Florian Egger ◽  
Dominic Blumenauer ◽  
Patrick Fischer ◽  
Andreas Venhorst ◽  
Saarraaken Kulenthiran ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Minute Ventilation ◽  
Anaerobic Exercise ◽  
Peak Oxygen Consumption ◽  
Exercise Tests ◽  
Maximum Performance ◽  
Outdoor Sports ◽  
Cardiorespiratory Response ◽  
Individual Anaerobic Threshold ◽  
The Individual

Abstract Background During the COVID-19 pandemic, compulsory masks became an integral part of outdoor sports such as jogging in crowded areas (e.g. city parks) as well as indoor sports in gyms and sports centers. This study, therefore, aimed to investigate the effects of medical face masks on performance and cardiorespiratory parameters in athletes. Methods In a randomized, cross-over design, 16 well-trained athletes (age 27 ± 7 years, peak oxygen consumption 56.2 ± 5.6 ml kg−1 min−1, maximum performance 5.1 ± 0.5 Watt kg−1) underwent three stepwise incremental exercise tests to exhaustion without mask (NM), with surgical mask (SM) and FFP2 mask (FFP2). Cardiorespiratory and metabolic responses were monitored by spiroergometry and blood lactate (BLa) testing throughout the tests. Results There was a large effect of masks on performance with a significant reduction of maximum performance with SM (355 ± 41 Watt) and FFP2 (364 ± 43 Watt) compared to NM (377 ± 40 Watt), respectively (p < 0.001; ηp2 = 0.50). A large interaction effect with a reduction of both oxygen consumption (p < 0.001; ηp2 = 0.34) and minute ventilation (p < 0.001; ηp2 = 0.39) was observed. At the termination of the test with SM 11 of 16 subjects reported acute dyspnea from the suction of the wet and deformed mask. No difference in performance was observed at the individual anaerobic threshold (p = 0.90). Conclusion Both SM and to a lesser extent FFP2 were associated with reduced maximum performance, minute ventilation, and oxygen consumption. For strenuous anaerobic exercise, an FFP2 mask may be preferred over an SM.

The Oxygen Consumption of an Echiuroid, Bonellia Viridis Rolando

1968 ◽  
Vol 48 (2) ◽  
pp. 427-434
Author(s):  
A. E. BRAFIELD
Keyword(s):  
Oxygen Consumption ◽  
Body Size ◽  
Continuous Flow ◽  
Muscular Activity ◽  
Dry Weight ◽  
The Body ◽  
Body Region ◽  
Rate Of Oxygen Consumption

1. The oxygen consumption of the echiuroid Bonellia viridis has been investigated by means of a continuous-flow polarographic respirometer. 2. The general rate of oxygen consumption per unit dry weight is similar to that characteristic of polychaetes, and declines exponentially with increasing body size. 3. The rate of oxygen consumption rises in the light and falls again if darkness is restored. 4. The oxygen consumption of the isolated proboscis plus that of the isolated body region corresponds closely to that of the entire animal. 5. The oxygen consumption per unit dry weight of the proboscis is considerably higher than that of the body region. 6. The oxygen consumption of an isolated body region increases in the presence of light, but that of an isolated proboscis does not. 7. These findings are discussed in relation to the biology of the animal, observed muscular activity, and the occurrence of the pigment bonellin.

The Relation of Oxygen Consumption to Body Size and to Temperature in the Larvae of Chironomus Riparius Meigen

1958 ◽  
Vol 35 (2) ◽  
pp. 383-395
Author(s):  
R. W. EDWARDS
Keyword(s):  
Oxygen Consumption ◽  
Body Size ◽  
Dry Matter ◽  
Larval Instar ◽  
Weight Ratio ◽  
Dry Weight ◽  
Chironomus Riparius ◽  
Consumption Rates ◽  
Rate Of Oxygen Consumption ◽  
Wet Weight

1. The oxygen consumption rates of 3rd- and 4th-instar larvae of Chironomus riparius have been measured at 10 and 20° C. using a constant-volume respirometer. 2. The oxygen consumption is approximately proportional to the 0.7 power of the dry weight: it is not proportional to the estimated surface area. 3. This relationship between oxygen consumption and dry weight is the same at 10 and at 20° C.. 4. The rate of oxygen consumption at 20° C. is greater than at 10° C. by a factor of 2.6. 5. During growth the percentage of dry matter of 4th-instar larvae increases from 10 to 16 and the specific gravity from 1.030 to 1.043. 6. The change in the dry weight/wet weight ratio during the 4 larval instar supports the theory of heterauxesis. 7. At 20° C., ‘summer’ larvae respire faster than ‘winter’ larvae.

Influence of age, fat cell weight, and obesity on O2 consumption of human adipose tissue

1989 ◽  
Vol 256 (4) ◽  
pp. E467-E474 ◽  
Author(s):  
P. Hallgren ◽  
L. Sjostrom ◽  
H. Hedlund ◽  
L. Lundell ◽  
L. Olbe
Keyword(s):  
Adipose Tissue ◽  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Human Adipose Tissue ◽  
Fat Cell ◽  
Cell Weight ◽  
Total Body ◽  
Obese Human ◽  
Open Question ◽  
Partial Weight

The oxygen consumption of human adipose tissue (AT) was determined in 53 adults, lean and obese, and in nine lean boys. The oxygen consumption was positively related to fat cell weight and negatively to age and degree of obesity. Men and women did not differ with respect to oxygen consumption of AT. The positive relationship between oxygen consumption per cell and fat cell size was also demonstrated in size-separated cells from the same donors. Expressed per cell the oxygen consumption was higher in fat cells from obese than in cells from lean subjects, but expressed per gram of tissue the opposite result was found. The oxygen consumption of the total AT organ was higher in obese than in lean subjects. The energy expenditure of AT constituted approximately 4% of the estimated 24-h energy expenditure in both groups. It is concluded that obese subjects do not maintain their obesity because of a reduced energy expenditure of the total AT (or of the total body). After a partial weight reduction in five subjects, the energy metabolism tended to change in direction toward the conditions seen in lean subjects. However, it is still an open question whether the observed energy metabolic aberrations of obese human AT are only secondary to the obese state or partly primary and thus of etiological importance.

scholarly journals Variation in body size of Phanocerus clavicornis Sharp, 1882 (Coleoptera: Elmidae: Larainae) in Atlantic Rainforest streams in response to hydraulic disturbance

2013 ◽  
Vol 73 (4) ◽  
pp. 747-752 ◽  
Author(s):  
MO. Segura ◽  
T. Siqueira ◽  
AA. Fonseca-Gessner
Keyword(s):  
Body Size ◽  
Total Body Length ◽  
Atlantic Rainforest ◽  
Southeastern Brazil ◽  
Head Width ◽  
High Plasticity ◽  
Larval Size ◽  
Morphometric Variation ◽  
Total Body ◽  
Rain Events

In this study, patterns of body size of Phanocerus clavicornis Sharp, 1882 (Coleoptera: Elmidae: Larainae) were investigated along a gradient of change in speed of flow conditions in streams of low order in the Atlantic Rainforest in southeastern Brazil. Specifically, the hypothesis that the distribution of P. clavicornis larvae vary in size in response to variations in the speed of flow in streams was tested. A Surber sampler was used to collect larvae from the streambed during two sampling periods, defined by the rain regime: August in the dry season and February in the rainy season. Possible differences in mean measured body size were tested by analysis of variance (ANOVA). The ANOVA result indicated for all measurements on the larvae collected in first-order streams (head width, prothoracic width and total body length), there were significant differences indicating a morphometric variation due to changing hydraulic conditions, the smallest larvae being associated with the period of greater rainfall. However, the larger streams (3rd order), where the rain events had less impact on the larval size, varied widely. The results of this study suggest that the interstitial space is important for the protection of the larvae from water flow, and that populations of P. clavicornis have high plasticity, a key feature for the occupation of unstable environments for this species. These results are important for an understanding of the life history and behavioural characteristics of the species, which allow them to persist in streams along a gradient of flow disturbance.

Appearance of excess lactate in anesthetized dogs during anemic and hypoxic hypoxia

1965 ◽  
Vol 209 (3) ◽  
pp. 604-610 ◽  
Author(s):  
Stephen M. Cain
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Oxygen Transport ◽  
Liver Dysfunction ◽  
Hypoxic Hypoxia ◽  
Blood Gas ◽  
Total Oxygen ◽  
Anesthetized Dogs ◽  
Lactate And Pyruvate ◽  
Mixed Venous

Ten anesthetized, splenectomized dogs were made progressively anemic by replacement of blood with warmed dextran to approximate hematocrits of 30, 20, 15, and 10%. A second group of 10 dogs was made progressively hypoxic by having them inspire 11.4, 9.5, 8.0, and 5.9% O2 in N2. Blood gas contents, pH, and gas tensions were measured in arterial and mixed venous bloods. Cardiac output was calculated from the arteriovenous O2 difference and the O2 uptake. Excess lactate was calculated from measured levels of lactate and pyruvate in blood water. Excess lactate appeared at higher mixed venous Po2 in anemic animals than in hypoxic, 40 mm Hg versus 20 mm Hg. When related to total oxygen transport, however, excess lactate appeared at about the same point (12 ml/kg per min) in both groups. Because liver has been shown to reduce its oxygen uptake with any lowering of perfusate oxygen content, it was suggested that the excess lactate measured during both anemic and hypoxic hypoxia in anesthetized dogs is largely the result of liver dysfunction with respect to lactate.

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