Oxygen consumption of profundal lake animals at low oxygen content of the water

Hydrobiologia ◽  
1965 ◽  
Vol 26 (1-2) ◽  
pp. 131-143 ◽  
Author(s):  
Kaj Berg ◽  
Pétur M. Jónasson
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Content ◽  
Low Oxygen

scholarly journals The Function of the Gills of Mayfly Nymphs from Different Habitats

1939 ◽  
Vol 16 (3) ◽  
pp. 363-373 ◽  
Author(s):  
C. A. WINGFIELD
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Content ◽  
The Body ◽  
Gaseous Exchange ◽  
Low Oxygen ◽  
Respiratory Mechanism ◽  
Tracheal Gills ◽  
Cloeon Dipterum ◽  
Gill Function ◽  
Oxygen Concentrations

1. The oxygen consumption of normal and gill-less nymphs of the mayflies Baetis sp., Cloeon dipterum and Ephemera vulgata has been measured at various oxygen concentrations. 2. It has been found that over the complete range of oxygen concentrations studied, the tracheal gills do not aid oxygen consumption in Baetis sp. In Cloeon dipterum, at all oxygen concentrations tested, no gaseous exchange takes place through the gills; at low oxygen concentrations, however, the gills function as an accessory respiratory mechanism in ventilating the respiratory surface of the body and so aid oxygen consumption. In Ephemera Vulgata the gills aid oxygen consumption even at high oxygen concentrations. In this species the gills may function both as true respiratory organs and as a ventilating mechanism. 3. It is shown that the differences in gill function can be related to the oxygen content of the habitat of each species.

scholarly journals False Oxygen Consumption Effect and Factors Causing It

2011 ◽  
Vol 2011 ◽  
pp. 1-5
Author(s):  
M. V. Miniaev ◽  
M. B. Belyakova ◽  
N. V. Kostiuk ◽  
D. V. Leshchenko
Keyword(s):  
Oxygen Consumption ◽  
Low Temperature ◽  
Oxygen Content ◽  
Incubation Medium ◽  
Low Oxygen ◽  
Salting Out ◽  
Low Concentration ◽  
Initial Oxygen Content ◽  
Initial Oxygen

False oxygen consumption effect characterized by a decrease of the polarographic sensor readings by the introduction of neutral microadditives into the incubation medium was modeled and tested. These neutral microadditives neither consume oxygen nor cause its consumption by other components of the medium. It is shown that microadditives less than 3% of the volume of incubation medium can cause statistically significant effect of false oxygen consumption more than 4% of the initial oxygen content. The effect can reach more than 15% at higher volumes of additives. The most important properties of additives enhancing the effect are low oxygen content, low temperature, and low concentration of oxygen salting out components.

scholarly journals The Respiration of Freshwater Snails

1959 ◽  
Vol 36 (4) ◽  
pp. 690-708
Author(s):  
KAJ BERG ◽  
K. W. OCKELMANN
Keyword(s):  
Oxygen Consumption ◽  
Body Size ◽  
Oxygen Content ◽  
Oxygen Supply ◽  
Regression Line ◽  
Live Weight ◽  
Interspecific Variation ◽  
Freshwater Snails ◽  
Low Oxygen ◽  
Bithynia Tentaculata

1. The oxygen consumption of some Danish freshwater snails was studied in relation to varying periods of starvation, varying temperatures, weight of animals and oxygen content of the water. The observed respiration is a moderately active metabolism, not a basal one. 2. In the case of Lymnaea palustris and Bithynia leachi a distinct decrease of oxygen consumption has been found in the period 1-24 hr. after collecting; the decrease is supposed to be caused by starvation. In similar experiments Lymnaea pereger, Myxas giutinosa, Bithynia tentaculata, Valvata piscinalis and possibly Physafontinalis and Lymnaea auricularia show only a small decrease (or no decrease) of oxygen consumption. 3. During a gradual increase of the temperature (c. I° C. per hr.) the snails increase their oxygen consumption by 65-90% of the increase expected from Krogh's curve. In the case of Myxas glutinosa and Physa fontinalis the increase of respiration was nearly the same as that found by Krogh for other animals. 4. The relation of oxygen consumption to body size (live weight) is not a fixed, unchangeable quantity characteristic of every species, but may vary seasonally. A tentative explanation of this variation is given. 5. The oxygen consumption in relation to body size has also an interspecific variation. In prosobranchs the slopes b of the regression lines in a logarithmic co-ordinate system have in some cases nearly the magnitude 0.67 required by the surface law, but others are higher, e.g. c. 0.95. In pulmonates the relation varies as much as from b=c. 0.45 to b=c. 1.00, i.e. between less than proportional to surface and proportional to weight. 6. The oxygen consumption of the freshwater snails in relation to the sizes of the standard individuals is depicted in a logarithmic co-ordinate system as a belt showing only a slight deviation (Fig. 4, p. 697), i.e. the snails regarded as a whole have a fairly uniform respiration. The regression line of oxygen consumption to sizes of the standard individuals seems to be expressed by a regression line with a slope just under 1.0. 7. Experiments on oxygen consumption in relation to oxygen content of the water have shown that some species (Lymnaea auricularia, Myxas glutinosa, Physafontinalis, Valvata piscinalis and Bithynia leachi) are able to maintain their consumption with decreasing oxygen content of the water to a critical point of oxygen supply. But in some other species (Lymnaea pereger, L. palustris and Bithynia tentaculata) oxygen consumption decreases immediately in response to a declining oxygen supply. 8. In some freshwater snails (Myxas glutinosa, Lymnaea pereger, Physa fontinalis) the decrease in oxygen consumption in response to a decreasing oxygen supply is not gradual, but shows a steep fall below certain low values of the oxygen content. The only species able to maintain a comparatively high oxygen consumption at low oxygen supply is Bithynia leachi.

The Organic Metabolism of Sea-water with Special Reference to the Ultimate Food Cycle in the Sea

1935 ◽  
Vol 20 (2) ◽  
pp. 181-196 ◽  
Author(s):  
Ancel Keys ◽  
E. H. Christensen ◽  
August Krogh
Keyword(s):  
Oxygen Consumption ◽  
Special Reference ◽  
Oxygen Content ◽  
Sea Water ◽  
Raw Water

Studies are reported of the behaviour of stored sea-water with regard to oxygen, ammonia, and bacteria content in relation to the conditions of storage and to the effect of various filtration procedures.When sea-water is sterilised by filtration and stored in the dark, the oxygen content remains constant or diminishes only by less than 0·07c.c. per litre in several hundred hours.In non-sterile experiments there is always an oxygen consumption roughly parallel to a bacterial multiplication which begins very suddenly after collection of the water. These effects are greatest in “raw” water, less in paper-filtered water and least in water which is doubly filtered.

Effect of the Sintering Atmosphere on the Corrosion Resistance of Titanium for Application as Biomaterial

2012 ◽  
Vol 727-728 ◽  
pp. 85-89
Author(s):  
Luzinete P. Barbosa ◽  
Elki C. Souza ◽  
Lucio Salgado ◽  
I. Costa
Keyword(s):  
Corrosion Resistance ◽  
Oxygen Content ◽  
Passive Film ◽  
Titanium Surface ◽  
Sintered Titanium ◽  
Nacl Solution ◽  
Low Oxygen ◽  
Sintering Atmosphere ◽  
Corrosion Tests ◽  
Vacuum Atmosphere

In this work, the effect of sintering atmosphere on the corrosion resistance of sintered titanium has been evaluated in 0.9 % aqueous NaCl solution to simulate physiological environment. Corrosion tests were performed on titanium porous sintered under vacuum and vacuum plus dynamic argon. The results showed better passive properties associated to the titanium sintered under argon plus vacuum atmosphere than to the vacuum sintered titanium. The better corrosion resistance of the argon plus vacuum sintered titanium was attributed to the formation of a thin passive film on the titanium surface during sintering due the low oxygen content present in this atmosphere.

scholarly journals THE MORPHOLOGICAL CHANGES IN THE TISSUES OF THE RABBIT AS A RESULT OF REDUCED OXIDATION

1918 ◽  
Vol 27 (3) ◽  
pp. 399-412 ◽  
Author(s):  
H. G. Martin ◽  
A. S. Loevenhart ◽  
C. H. Bunting
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Content ◽  
Morphological Changes ◽  
Low Oxygen ◽  
High Carbon ◽  
Red Bone Marrow ◽  
Hydropic Degeneration ◽  
Thyroid Hyperplasia ◽  
High Carbon Dioxide ◽  
Stimulation Of

Exposure of rabbits to an atmosphere of low oxygen content results in a stimulation of the cardiorespiratory systems, in an extension (hyperplasia) of red bone marrow and probably of a thyroid hyperplasia, with the further production of hydropic and hyaline degeneration in the cells of the parenchymatous organs. An atmosphere of high carbon dioxide and normal oxygen content produces, however, a stimulation of the cardiorespiratory systems, but no marrow extension and, in the concentrations used, but slight hydropic degeneration in the parenchyma of the glandular organs.

Cardiovascular changes in the exercising emu

1983 ◽  
Vol 104 (1) ◽  
pp. 193-201 ◽  
Author(s):  
B. Grubb ◽  
D. D. Jorgensen ◽  
M. Conner
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Stroke Volume ◽  
Oxygen Content ◽  
Body Mass ◽  
Fold Increase ◽  
Exercise Heart Rate ◽  
Rate Of Oxygen Consumption ◽  
Cardiovascular Variables

Cardiovascular variables were studied as a function of oxygen consumption in the emu, a large, flightless ratite bird well suited to treadmill exercise. At the highest level of exercise, the birds' rate of oxygen consumption (VO2) was approximately 11.4 times the resting level (4.2 ml kg-1 min-1). Cardiac output was linearly related to VO2, increasing 9.5 ml for each 1 ml increase in oxygen consumption. The increase in cardiac output is similar to that in other birds, but appears to be larger than in mammals. The venous oxygen content dropped during exercise, thus increasing the arteriovenous oxygen content difference. At the highest levels of exercise, heart rate showed a 3.9-fold increase over the resting rate (45.8 beats min-1). The mean resting specific stroke volume was 1.5 ml per kg body mass, which is larger than shown by most mammals. However, birds have larger hearts relative to body mass than do mammals, and stroke volume expressed per gram of heart (0.18 ml g-1) is similar to that for mammals. Stroke volume showed a 1.8-fold increase as a result of exercise in the emus, but a change in heart rate plays a greater role in increasing cardiac output during exercise.

Preparation for Advanced Airway Management: Pre-oxygenation and Positioning

2019 ◽  
Author(s):  
Arpan Mehta ◽  
Adrian Pichurko
Keyword(s):  
Oxygen Consumption ◽  
Airway Management ◽  
Oxygen Content ◽  
High Flow ◽  
Nasal Cannula ◽  
Blood Oxygen ◽  
High Flow Nasal Cannula ◽  
Advanced Airway ◽  
Total Body ◽  
Total Body Oxygen

Preoxygenation allows a margin of safety prior to establishing control of a patient’s airway. Effective preoxygenation is influenced by careful technique, respiratory physiology, blood oxygen content, and total body oxygen consumption. Total body oxygen consumption is increased in the pregnant, pediatric, and obese populations, making maintenance of oxygenation more difficult during apnea. In addition to a standard facemask, advanced equipment such as high-flow nasal cannula, THRIVE, and various mask variants may be used. Positioning of a patient for advanced airway management affects preoxygenation, respiratory mechanics, and the conditions for establishing a definitive airway. The “triple airway support” maneuver consists of head extension, neck flexion, and protrusion of the mandibular teeth over the upper teeth; and provides effective mechanics for positive-pressure mask ventilation. Patients with potentially unstable cervical spines present additional challenges and, especially in emergency situations, require careful negotiation of priorities. Common maneuvers such as head tilt, jaw thrust, cricoid pressure, and manual in-line stabilization can cause motion in the unstable cervical spine with uncertain effects.  This review contains 7 figures, 5 tables, and 43 references. Keywords: preoxygenation, functional residual capacity, blood oxygen content, alveolar fraction of oxygen, total body oxygen consumption, high-flow nasal cannula, apneic oxygenation, sniffing position, triple airway support maneuver, manual in-line stabilization

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