Effects of High Temperature on Survival of the Giant Scallop

1958 ◽  
Vol 15 (6) ◽  
pp. 1189-1211 ◽  
Author(s):  
L. M. Dickie
Keyword(s):  
High Temperature ◽  
Temperature Acclimation ◽  
Direct Result ◽  
Acclimation Temperature ◽  
Lethal Temperature ◽  
Temperature Changes ◽  
Naturally Occurring ◽  
Special Circumstances ◽  
Summer Decline ◽  
Sudden Temperature Change

Upper lethal temperatures of scallops are raised 1 °C. by each increase of 5 °C. in acclimation temperature. Acclimation upwards is fairly rapid (average 1.7 °C. per day over part of the range). Loss of acclimation to high temperature is slow, and appears to take as long as 3 months. There is a winter-to-summer decline in lethal temperature. It appears that naturally occurring water temperatures over 23.5 °C. will be lethal to scallops and directly responsible for mortalities. Temperatures over 21 °C. may also be a direct cause of mortalities but only in special circumstances could mortalities occur as a direct result of temperatures below this. In the "sub-lethal" temperature range, sudden temperature changes upward or downward may so reduce scallop mobility as to make them easier prey to enemies. In this way sudden temperature change could be an indirect cause of increased mortality.

Resistance of Four Freshwater Crustaceans to Lethal High Temperature and Low Oxygen

1963 ◽  
Vol 20 (2) ◽  
pp. 387-415 ◽  
Author(s):  
J. B. Sprague
Keyword(s):  
High Temperature ◽  
Acclimation Temperature ◽  
Field Observations ◽  
Low Oxygen ◽  
Lethal Temperature ◽  
Natural Conditions ◽  
Short Survival ◽  
Lethal Temperatures ◽  
Gammarus Fasciatus ◽  
Gammarus Pseudolimnaeus

The crustaceans studied were the isopod Asellus intermedius Forbes, and the amphipods Hyalella azteca (Saussure), Gammarus fasciatus Say, and Gammarus pseudolimnaeus Bousfield.Resistance to high temperature decreased with size in A. intermedius and G. fasciatus, but no difference was found for H. azteca. Female Gammarus, were more resistant than males, there was no difference for A. intermedius, and a variable relation in H. azteca. Acclimation temperature could be raised at rates of 2.5 to 5 °C per day, at temperatures above 14 °C. Raising acclimation from 10 to 20 °C increased the lethal temperature (50% mortality in 24 hours) by 1.9 °C in G. fasciatus, 1.3 °C in A. intermedius, 0.5 °C in G. pseudolimnaeus, and apparently not at all in H. azteca. There was no seasonal variation in resistance after A. intermedius was acclimated in the laboratory.Two difficulties encountered were mortality during acclimation and short survival of controls, but careful checking showed that neither greatly affected the reported resistance.Estimates of the ultimate 24-hour lethal temperatures were 34.6 °C for A. intermedius and G. fasciatus, 33.2 °C for H. azteca, and 29.6 °C for G. pseudolimnaeus. The concentrations of low oxygen causing 50% mortality in 24 hours, with acclimation and testing at 20 °C, were.0.03 mg/l for A. intermedius, 0.7 mg/l for H. azteca, 2.2 mg/l for G. pseudolimnaeus, and 4.3 mg/l for G. fasciatus. Lethal temperatures would seldom seem to affect distribution under natural conditions, but resistance to low oxygen fits field observations fairly closely.

Mechanisms of Acid-Base Adjustment in Dogfish (Scyliorhinus Stellaris) Subjected to Long-Term Temperature Acclimation

1980 ◽  
Vol 85 (1) ◽  
pp. 89-98
Author(s):  
N. HEISLER ◽  
P. NEUMANN ◽  
G. F. HOLETON
Keyword(s):  
Temperature Acclimation ◽  
Temperature Adaptation ◽  
Acclimation Temperature ◽  
Acid Base ◽  
Temperature Changes ◽  
Base Parameters ◽  
Intracellular Compartments ◽  
Relationship Of ◽  
The Relationship

Specimens of Larger Spotted Dogfish (Scyliorhinus stellaris) were acclimated to a range of temperatures for 22–28 days. The relationships of pH to acclimation temperature in the extracellular space and in three intracellular compartments were essentially the same as previously observed in 24 h acclimated dogfish (Heisler, Weitz & Weitz, 1976). In dogfish subjected to elevated inspired PCO2 during acclimation to low temperature, there was an inversion in the relationship of acclimation temperature to plasma PCO2, and in that to plasma bicarbonate, whereas the relationships to pH values were unchanged. It is concluded that the temperature adaptation of the acid-base parameters is complete after 24 h of temperature acclimation. At least the following mechanisms are involved in the adjustment of pH with changes of temperature: changes of PCO2, changes of buffer pK values, and transmembrane transfer of bicarbonate. Apparently only one of them, the transmembrane transfer of bicarbonate, can be modulated in a sufficient range and is responsible for the final pH adjustment.

POTOMAC

Alloy Digest ◽  
1975 ◽  
Vol 24 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Heat Treating ◽  
General Purpose ◽  
Low Carbon ◽  
Repeated Heating ◽  
Temperature Changes ◽  
Heating And Cooling ◽  
Temperature Performance ◽  
Heat Checking

Abstract POTOMAC is a general-purpose, low-carbon, chromium-molybdenum-tungsten hot-work steel. It has excellent resistance to shock and heat checking after repeated heating and cooling. Potomac is suitable for hot-work applications involving severe conditions of shock and sudden temperature changes. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, and machining. Filing Code: TS-290. Producer or source: Allegheny Ludlum Corporation.

scholarly journals Modeling indicates degradation of mRNA and protein as a potential regulation mechanisms during cold acclimation

2021 ◽  
Author(s):  
Maria Krantz ◽  
Julia Legen ◽  
Yang Gao ◽  
Reimo Zoschke ◽  
Christian Schmitz-Linneweber ◽  
...  
Keyword(s):  
Protein Degradation ◽  
Temperature Acclimation ◽  
Ode Model ◽  
Future Directions ◽  
Chloroplast Gene Expression ◽  
Temperature Changes ◽  
Regulation Mechanisms ◽  
Photosynthetic Complexes ◽  
Photosynthetic Reactions ◽  
Account Temperature

AbstractPlants are constantly exposed to temperature fluctuations, which have direct effects on all cellular reactions because temperature influences reaction likelihood and speed. Chloroplasts are crucial to temperature acclimation responses of plants, due to their photosynthetic reactions whose products play a central role in plant metabolism. Consequently, chloroplasts serve as sensors of temperature changes and are simultaneously major targets of temperature acclimation. The core subunits of the complexes involved in the light reactions of photosynthesis are encoded in the chloroplast. As a result, it is assumed that temperature acclimation in plants requires regulatory responses in chloroplast gene expression and protein turnover. We conducted western blot experiments to assess changes in the accumulation of two photosynthetic complexes (PSII, and Cytb6f complex) and the ATP synthase in tobacco plants over two days of acclimation to low temperature. Surprisingly, the concentration of proteins within the chloroplast varied negligibly compared to controls. To explain this observation, we used a simplified Ordinary Differential Equation (ODE) model of transcription, translation, mRNA degradation and protein degradation to explain how the protein concentration can be kept constant. This model takes into account temperature effects on these processes. Through simulations of the ODE model, we show that mRNA and protein degradation are possible targets for control during temperature acclimation. Our model provides a basis for future directions in research and the analysis of future results.

Research on Temperature Changes and Microstructure Evolution of Steel Target after the Penetration by Copper Jet

2011 ◽  
Vol 311-313 ◽  
pp. 953-956
Author(s):  
Hao Chen ◽  
Gang Tao
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Temperature Distribution ◽  
Microstructure Evolution ◽  
Deformation Zone ◽  
Superplastic Deformation ◽  
Theoretical Formula ◽  
Temperature Changes ◽  
Normal Deformation ◽  
Steel Target

In order to study dynamic response of metal, this paper makes use of theoretical formula to investigate changes of temperature and grain size on steel target after the penetration of copper jet based on data gathered from the experiments. Deformed target penetrated by copper jet could be divided into superplastic deformation zone and normal deformation zone according to the different microstructure. Temperature distribution of each deformation zones is in turn calculated by two constitutive equations. The results indicate that areas with high temperature concentrate on the narrow zone near the penetrated channel. Then, the calculation of grain size conforms to the observation. It is obviously proven that the method used in this paper is trustworthy for calculating the changes of temperature and grain size of target caused by penetration.

Design and use of an Efficient Plasma Jet Reactor for High Temperature Gas/Solid Reactions

1983 ◽  
Vol 30 ◽  
Author(s):  
F. W. Giacobbe ◽  
D. W. Schmerling
Keyword(s):  
Carbon Monoxide ◽  
High Temperature ◽  
Arc Discharge ◽  
Plasma Jet ◽  
Direct Result ◽  
Discharge Region ◽  
Plasma Flame ◽  
Powdered Carbon ◽  
High Yields ◽  
Experimental Trials

ABSTRACTA unique and efficient plasma jet reactor has been developed and used to study the high temperature production of carbon monoxide from a reaction between powdered carbon and a pure carbon dioxide plasma. The plasma jet reactor was designed to allow the injection of powdered carbon above the arc discharge region rather than into the plasma flame below the arc discharge region. High yields of carbon monoxide, produced at relatively high efficiencies, were a direct result of this technique. The plasma jet was also designed to enable rapid changing and testing of various anode insertsAverage yields of carbon monoxide in the product gases were as high as 80–87% in selected experimental trials. Carbon monoxide was produced at rates exceeding 15,000 1/hr (at STP) with a power expenditure of 52 Kw.

Pre-anthesis high-temperature acclimation alleviates damage to the flag leaf caused by post-anthesis heat stress in wheat

2011 ◽  
Vol 168 (6) ◽  
pp. 585-593 ◽  
Author(s):  
Xiao Wang ◽  
Jian Cai ◽  
Dong Jiang ◽  
Fulai Liu ◽  
Tingbo Dai ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Flag Leaf ◽  
Temperature Acclimation

Intracellular pH-temperature interactions of hepatocytes from American eels

1983 ◽  
Vol 245 (1) ◽  
pp. R32-R37
Author(s):  
P. J. Walsh ◽  
T. W. Moon
Keyword(s):  
Intracellular Ph ◽  
Acclimation Temperature ◽  
C Cells ◽  
Medium Ph ◽  
American Eel ◽  
Temperature Changes ◽  
American Eels ◽  
Temperature Interactions

The effects of acclimation temperature and acute temperature changes on the intracellular pH (pHi) of hepatocytes isolated from the American eel, Anguilla rostrata, were studied by the measurement of the distribution ratio of dimethyloxizolidinedione (DMO). Varying the concentration of DMO (10(-7) to 10(-4) M) did not affect estimates of pHi, indicating that DMO acts as an ideal pHi probe in eel hepatocytes. In vitro studies yielded values of liver cell pHi identical to those previously measured in vivo (in vitro pHi = 7.556 +/- 0.010; in vivo pHi = 7.570 +/- 0.049 at 20 degrees C); hepatocyte pHi varied inversely with acclimation temperature (5-20 degrees C) in a manner consistent with alphastat regulation (delta pH/delta T = -0.0182 +/- 0.021). During acute temperature increases (5-20 degrees C) and decreases (20-5 degrees C) hepatocytes regulated pHi to the appropriate (acclimated) value within 30-45 min posttransfer under conditions of constant medium pH (pHe). The effects of medium pH were also studied, and although patterns of pHi regulation differed between 5 and 20 degrees C cells, a pHi difference consistent with alphastat regulation was maintained between 5 and 20 degrees C cells over the pHe range 7.8-8.3.

FLAVOUR REVERSION IN HYDROGENATED LINSEED OIL: I. THE PRODUCTION OF AN ISOMER OF LINOLEIC ACID FROM LINOLENIC ACID

1944 ◽  
Vol 22f (6) ◽  
pp. 191-198 ◽  
Author(s):  
H. W. Lemon
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
High Temperature ◽  
Iodine Number ◽  
Spectral Method ◽  
Linolenic Acid ◽  
Linseed Oil ◽  
Naturally Occurring ◽  
Total Fatty Acids ◽  
Isomeric Acid

Linseed oil that has been hydrogenated to a plastic consistency is subject to a type of deterioration termed "flavour reversion" when heated to temperatures used in baking or frying. Investigation of the course of hydrogenation of linseed oil by the spectral method of Mitchell, Kraybill, and Zscheile (11) has indicated that linolenic acid is converted to an isomeric linoleic acid; this acid differs from naturally occurring linoleic acid in that the double bonds are in such positions that diene conjugation is not produced by high-temperature saponification. In a typical hydrogenation, the concentration of the isomeric acid increased to a maximum, at about iodine number 120, of 18% of the total fatty acids, and at iodine number 80, at which point the plasticity was similar to that of a commercial shortening, the concentration of the isomer was 13%. Evidence is presented that the isomeric linoleic acid in partially hydrogenated linseed oil is responsible for the unpleasant flavour that develops when the oil is heated.

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