scholarly journals Direct measurements of the light dependence of gross photosynthesis and oxygen consumption in the ocean

2017 ◽  
Vol 62 (3) ◽  
pp. 1066-1079 ◽  
Author(s):  
Benjamin Bailleul ◽  
Jisoo Park ◽  
Christopher M. Brown ◽  
Kay D. Bidle ◽  
Sang Hoon Lee ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Gross Photosynthesis ◽  
Light Dependence ◽  
Direct Measurements

Light dependence of oxygen consumption by blowfly eyes recorded with a magnetic diver balance

2004 ◽  
Vol 191 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Tina Pangršič ◽  
Peter Stušek ◽  
Gregor Belušič ◽  
Gregor Zupančič
Keyword(s):  
Oxygen Consumption ◽  
Light Dependence

Oxidation of mine tailings from Rankin Inlet, Nunavut, at subzero temperatures

2001 ◽  
Vol 38 (5) ◽  
pp. 957-966 ◽  
Author(s):  
J L Meldrum ◽  
H E Jamieson ◽  
L D Dyke
Keyword(s):  
Oxygen Consumption ◽  
Pore Water ◽  
Mine Drainage ◽  
Experimental Program ◽  
Unfrozen Water ◽  
Hudson Bay ◽  
Oxidation Reactions ◽  
Subzero Temperatures ◽  
Direct Measurements

Acid-generating sulphidic tailings from a Ni–Cu mine were exposed on the shores of Hudson Bay for 30 years before burial in a drained bedrock basin. To determine if encapsulation in permafrost will maintain the tailings, and their saline pore water, in a chemically inert state, a field and experimental program was employed. Three years after burial, several boreholes were drilled to collect tailings and pore-water samples and to initiate long-term thermal monitoring. Columns charged with pyrrhotite-bearing, unsaturated tailings were studied at temperatures between +30°C and –10°C. Oxygen consumption was measured directly to determine the effect of low temperatures on oxidation rate. Results of the column experiments indicate that significant oxidation of the Rankin Inlet tailings occurs at +30°C, but at lower temperatures this rate is substantially reduced. At –10°C, unfrozen water was still present in the columns, but oxygen consumption was below the detection limit. The highest measured oxygen flux correlates with a temperature increase of 1°C, consistent with exothermic sulphide oxidation reactions. Thermal modeling and direct measurements have shown that the freezing of the tailings in Rankin Inlet is progressing. The tailings are expected to be ice-bonded approximately 15 years after burial.Key words: acid mine drainage, permafrost, tailings, reclamation, sulphides, oxidation

Clinical and Experimental Analysis of 201Thallium Uptake of the Heart

1978 ◽  
Vol 17 (04) ◽  
pp. 142-148
Author(s):  
U. Büll ◽  
S. Bürger ◽  
B. E. Strauer
Keyword(s):  
Oxygen Consumption ◽  
Left Ventricle ◽  
Muscle Mass ◽  
Myocardial Oxygen Consumption ◽  
Animal Experiments ◽  
Left Ventricular ◽  
Left Ventricular Wall ◽  
Ventricular Wall ◽  
Flow Measurements ◽  
Myocardial Flow

Studies were carried out in order to determine the factors influencing myocardial 201T1 uptake. A total of 158 patients was examined with regard to both 201T1 uptake and the assessment of left ventricular and coronary function (e. g. quantitative ventriculography, coronary arteriography, coronary blood flow measurements). Moreover, 42 animal experiments (closed chest cat) were performed. The results demonstrate that:1) 201T1 uptake in the normal and hypertrophied human heart is linearly correlated with the muscle mass of the left ventricle (LVMM);2) 201T1 uptake is enhanced in the inner (subendocardial) layer and is decreased in the outer (subepicardial) layer of the left ventricular wall. The 201T1 uptake of the right ventricle is 40% lower in comparison to the left ventricle;3) the basic correlation between 201T1 uptake and LVMM is influenced by alterations of both myocardial flow and myocardial oxygen consumption; and4) inotropic interventions (isoproterenol, calcium, norepinephrine) as well as coronary dilatation (dipyridamole) may considerably augment 201T1 uptake in accordance with changes in myocardial oxygen consumption and/or myocardial flow.It is concluded that myocardial 201T1 uptake is determined by multiple factors. The major determinants have been shown to include (i) muscle mass, (ii) myocardial flow and (iii) myocardial oxygen consumption. The clinical data obtained from patient groups with normal ventricular function, with coronary artery disease, with left ventricular wall motion abnormalities and with different degree of left ventricular hypertrophy are correlated with quantitated myocardial 201T1 uptake.

Oxygen Consumption in Platelets of Newborn Infants before and after Stimulation by Thrombin.

1976 ◽  
Vol 35 (03) ◽  
pp. 712-716 ◽  
Author(s):  
D. Del Principe ◽  
G Mancuso ◽  
A Menichelli ◽  
G Maretto ◽  
G Sabetta
Keyword(s):  
Oxygen Consumption ◽  
Cord Blood ◽  
Umbilical Cord ◽  
Newborn Infant ◽  
Umbilical Cord Blood ◽  
Newborn Infants ◽  
O2 Consumption ◽  
Adult Control ◽  
Healthy Newborn ◽  
Before And After

SummaryThe authors compared the oxygen consumption in platelets from the umbilical cord blood of 36 healthy newborn infants with that of 27 adult subjects, before and after thrombin addition (1.67 U/ml). Oxygen consumption at rest was 6 mμmol/109/min in adult control platelets and 5.26 in newborn infants. The burst in oxygen consumption after thrombin addition was 26.30 mμmol/109/min in adults and 24.90 in infants. Dinitrophenol did not inhibit the burst of O2 consumption in platelets in 8 out of 10 newborn infants, while the same concentration caused a decrease in 9 out of 10 adult subjects. Deoxyglucose inhibited the burst in O2 consumption in newborn infant and adult platelets by about 50%. KCN at the concentration of 10−4 M completely inhibited basal oxygen consumption but did not completely inhibit the burst after thrombin. At the concentration of 10−3 M, it inhibited both basal O2 consumption and the burst in infants and adult subjects.

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