Re-examination of the contributions of aerobic and anaerobic energy production during swimming in the Bivalve mollusc Limaria fragilis (Family Limidae)

1983 ◽  
Vol 34 (6) ◽  
pp. 909 ◽  
Author(s):  
J Baldwin ◽  
GM Morris
Keyword(s):  
Energy Production ◽  
Arginine Kinase ◽  
Adductor Muscle ◽  
Aerobic Metabolism ◽  
Anaerobic Glycolysis ◽  
Atp Production ◽  
Minor Contribution ◽  
Anaerobic Energy ◽  
A Minor ◽  
Aerobic And Anaerobic

The file shell L. fragilis displays a slow sustained style of swimming indicative of basically aerobic mechanisms of ATP production. Although it had been proposed that anaerobic glycolysis and arginine phosphate did not contribute to powering swimming, the discovery of high activity of arginine kinase and significant activities of strombine and alanopine dehydrogenases in the adductor muscle led to a reexamination of the relative contributions of aerobic metabolism, anaerobic glycolysis and arginine phosphate during swimming. It was found that, whereas aerobic metabolism predominates with only a minor contribution from anaerobic glycolysis, arginine phosphate supplied up to 23% of the ATP used during 5 min of sustained swimming.

A Comparison of Anaerobic Energy Metabolism in Mantle and Tentacle Muscle of the Blue-Ringed Octopus, Hapalochlaena maculosa, During Swimming

1980 ◽  
Vol 28 (3) ◽  
pp. 407 ◽  
Author(s):  
J Baldwin ◽  
WR England
Keyword(s):  
Lactate Dehydrogenase ◽  
Energy Metabolism ◽  
Energy Charge ◽  
Anaerobic Glycolysis ◽  
Atp Production ◽  
Glycerophosphate Dehydrogenase ◽  
Anaerobic Energy ◽  
Octopine Dehydrogenase

The blue-ringed octopus Hapalochlaena maculosa uses both the mantle and tentacles for swimming. Activities of octopine dehydrogenase. lactate dehydrogenase and alpha-glycerophosphate dehydrogenase in mantle and tentacle muscles indicate that both tissues depend on anaerobic glycolysis during swimming. with octopine rather than lactate accumulating as an end product. Following swimming. both mantle and tentacles show a decrease in arginine phosphate, an increase in octopine. and a fall in energy charge. On the basis of ATP equivalents per grain of muscle obtained from arginine phosphate and anaerobic glycolysis, the two tissues are similar, but when the relative muscle weights are taken into account ATP production is at least 10-fold greater in the tentacles than in the mantle.

scholarly journals The Influence of La and Ce on Microstructure and Mechanical Properties of an Al-Si-Cu-Mg-Fe Alloy at High Temperature

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 384
Author(s):  
Andong Du ◽  
Anders E. W. Jarfors ◽  
Jinchuan Zheng ◽  
Kaikun Wang ◽  
Gegang Yu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Temperature ◽  
Intermetallic Phases ◽  
High Temperature Strength ◽  
Thermal Expansion Mismatch ◽  
Strengthening Mechanisms ◽  
High Temperature Mechanical Properties ◽  
Minor Contribution ◽  
A Minor

The effect of lanthanum (La)+cerium (Ce) addition on the high-temperature strength of an aluminum (Al)–silicon (Si)–copper (Cu)–magnesium (Mg)–iron (Fe)–manganese (Mn) alloy was investigated. A great number of plate-like intermetallics, Al11(Ce, La)3- and blocky α-Al15(Fe, Mn)3Si2-precipitates, were observed. The results showed that the high-temperature mechanical properties depended strongly on the amount and morphology of the intermetallic phases formed. The precipitated tiny Al11(Ce, La)3 and α-Al15(Fe, Mn)3Si2 both contributed to the high-temperature mechanical properties, especially at 300 °C and 400 °C. The formation of coarse plate-like Al11(Ce, La)3, at the highest (Ce-La) additions, reduced the mechanical properties at (≤300) ℃ and improved the properties at 400 ℃. Analysis of the strengthening mechanisms revealed that the load-bearing mechanism was the main contributing mechanism with no contribution from thermal-expansion mismatch effects. Strain hardening had a minor contribution to the tensile strength at high-temperature.

scholarly journals Refugees and the Borders of Europe: A Minor Contribution

2015 ◽  
Vol 27 (1) ◽  
pp. 1-4
Author(s):  
Elena Loizidou
Keyword(s):  
Minor Contribution ◽  
A Minor

Estimation of anaerobic energy production and efficiency in rats during exercise

1984 ◽  
Vol 56 (2) ◽  
pp. 520-525 ◽  
Author(s):  
G. A. Brooks ◽  
C. M. Donovan ◽  
T. P. White
Keyword(s):  
Total Energy ◽  
Energy Production ◽  
Metabolic Response ◽  
Lactate Production ◽  
Energy Transduction ◽  
Energy Turnover ◽  
External Work ◽  
Gross Efficiency ◽  
Lactate Turnover ◽  
Anaerobic Energy

o assess the effects of gradient and running speed on efficiency of exercise, and to evaluate contributions of oxidative and anaerobic energy production (Ean) during locomotion, two sets of experiments were performed. The caloric expenditures of rats were determined from O2 consumption (VO2) while they ran at three speeds (13.4, 26.8, and 43.1 m/min) on five grades (1, 5, 10, 15, and 20%). In addition, lactate turnover (LaT) and oxidation (Laox) were determined on rats at rest or during running at 13.4 and 26.8 m/min on 1% grade, respectively. Lactate production not represented in the VO2 (i.e., Ean) was calculated from the LaT not accounted for by oxidation [(LaT an) = LaT-Laox)]. The Ean was calculated as: Ean = [LaT an(mumol/min)] [1.38 ATP/La] [11 mcal/mumol ATP]. Gross efficiency of exercise (the caloric equivalent of external work/caloric equivalent of VO2 X 100) ranged from 1.7 to 4.5%. Apparent efficiency (the inverse of the regression of caloric equivalent of VO2 on the caloric equivalent of work X 100) ranged from 20.5 to 26.4% and reflected the metabolic response of rats to applied external work. The contribution of Ean to total energy turnover ranged from 1.6% at rest to 0.8% during running at 13.4 m/min on a 1% grade. Despite active LaT during steady-state exercise, Ean contributes insignificantly to total energy transduction, because over 70% of the lactate produced is removed through oxidation. VO2 adequately represents metabolism under these conditions.

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