scholarly journals Functional significance of isoenzymes in thermal acclimatization. Acetylcholinesterase from trout brain

1970 ◽  
Vol 116 (5) ◽  
pp. 883-887 ◽  
Author(s):  
John Baldwin ◽  
P. W. Hochachka
Keyword(s):  
Rainbow Trout ◽  
Functional Significance ◽  
Catalytic Properties ◽  
Intermediate Temperature ◽  
Temperature Dependent ◽  
Thermal Acclimatization ◽  
And Control ◽  
Critical Process ◽  
Enzyme Variant ◽  
Brain Acetylcholinesterase

1. The effects of acclimatization temperature on the catalytic properties of acetylcholinesterase from rainbow-trout brain were examined. 2. Trout brain acetylcholinesterase occurs in two distinct forms. A single ‘warm’ variant of the enzyme is present after acclimatization to 17°C; a single ‘cold’ variant appears after acclimatization to 2°C. Both forms are present in fish after acclimatization to an intermediate temperature. 3. The Km values of the enzyme variants for acetylcholine are temperature-dependent, the lowest values coinciding with the acclimatization temperature at which each enzyme was induced. 4. It is concluded that the Km–temperature relationship is adaptive, and that the critical process during thermal acclimatization, in cases where enzymes show sharp changes in Km with temperature, is the synthesis of a new enzyme variant that is better suited for catalysis and control of catalysis under the conditions of the acclimatized state.

Brain Acetylcholinesterase Inhibition and Hepatic Activation of Acephate and Fenitrothion in Rainbow Trout (Salmo gairdneri)

1980 ◽  
Vol 37 (9) ◽  
pp. 1450-1453 ◽  
Author(s):  
J. F. Klaverkamp ◽  
B. R. Hobden
Keyword(s):  
Rainbow Trout ◽  
Liver Homogenate ◽  
Acetylcholinesterase Inhibition ◽  
Salmo Gairdneri ◽  
Ache Inhibitor ◽  
Temperature Dependent ◽  
Brain Ache ◽  
Two Factors ◽  
Brain Acetylcholinesterase ◽  
Hepatic Biotransformation

Two factors, potency of brain acetylcholinesterase (AChE) inhibition and biotransformation by liver homogenate, were investigated to understand the temperature-dependent toxicity of fenitrothion (FTN) in rainbow trout (Salmo gairdneri) and the 600- to 1000-fold differences in concentration between FTN and another organophosphate (OP) insecticide, acephate (ATE), required to produce death in these trout. Concentrations required to produce 50% inhibition of brain AChE were similar for ATE and FTN, ~125 mmol/L and 80 mmol/L, respectively, whereas fenitrooxon (FTO), the oxidative desulfuration metabolite of FTN, was approximately five orders of magnitude more potent. Incubation with liver homogenate, however, demonstrated that a more potent brain AChE inhibitor was produced from ATE, but not from FTN. It is concluded that hepatic biotransformation of FTN to FTO does not explain previous observations of FTN temperature dependency and differences in concentrations producing lethality.Key words: acephate, acetylcholinesterase, biotransformation, brain, fenitrothion, fenitrooxon, liver

Recirculation versus flow-through rainbow trout laboratory Flavobacterium columnare challenge

2020 ◽  
Vol 139 ◽  
pp. 213-221
Author(s):  
C Birkett ◽  
R Lipscomb ◽  
T Moreland ◽  
T Leeds ◽  
JP Evenhuis
Keyword(s):  
Rainbow Trout ◽  
Environmental Parameters ◽  
Cumulative Effects ◽  
Flavobacterium Columnare ◽  
Replacement Rate ◽  
Bacterial Concentration ◽  
Water Replacement ◽  
Dose Concentration ◽  
Flow Through ◽  
And Control

Flavobacterium columnare immersion challenges are affected by water-related environmental parameters and thus are difficult to reproduce. Whereas these challenges are typically conducted using flow-through systems, use of a recirculating challenge system to control environmental parameters may improve reproducibility. We compared mortality, bacterial concentration, and environmental parameters between flow-through and recirculating immersion challenge systems under laboratory conditions using 20 rainbow trout families. Despite identical dose concentration (1:75 dilution), duration of challenge, lot of fish, and temperature, average mortality in the recirculating system (42%) was lower (p < 0.01) compared to the flow-through system (77%), and there was low correlation (r = 0.24) of family mortality. Mean days to death (3.25 vs. 2.99 d) and aquaria-to-aquaria variation (9.6 vs. 10.4%) in the recirculating and flow-through systems, respectively, did not differ (p ≥ 0.30). Despite 10-fold lower water replacement rate in the recirculating (0.4 exchanges h-1) compared to flow-through system (4 exchanges h-1), differences in bacterial concentration between the 2 systems were modest (≤0.6 orders of magnitude) and inconsistent throughout the 21 d challenge. Compared to the flow-through system, dissolved oxygen during the 1 h exposure and pH were greater (p ≤ 0.02), and calcium and hardness were lower (p ≤ 0.03), in the recirculating system. Although this study was not designed to test effects of specific environmental parameters on mortality, it demonstrates that the cumulative effects of these parameters result in poor reproducibility. A recirculating immersion challenge model may be warranted to empirically identify and control environmental parameters affecting mortality and thus may serve as a more repeatable laboratory challenge model.

scholarly journals Thermochromic aggregation-induced dual phosphorescence via temperature-dependent sp3-linked donor-acceptor electronic coupling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tao Wang ◽  
Zhubin Hu ◽  
Xiancheng Nie ◽  
Linkun Huang ◽  
Miao Hui ◽  
...  
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Electronic Coupling ◽  
Temperature Dependent ◽  
Molecular Systems ◽  
Donor And Acceptor ◽  
Theoretical Investigations ◽  
Donor Acceptor ◽  
And Control ◽  
Two Temperature

AbstractAggregation-induced emission (AIE) has proven to be a viable strategy to achieve highly efficient room temperature phosphorescence (RTP) in bulk by restricting molecular motions. Here, we show that by utilizing triphenylamine (TPA) as an electronic donor that connects to an acceptor via an sp3 linker, six TPA-based AIE-active RTP luminophores were obtained. Distinct dual phosphorescence bands emitting from largely localized donor and acceptor triplet emitting states could be recorded at lowered temperatures; at room temperature, only a merged RTP band is present. Theoretical investigations reveal that the two temperature-dependent phosphorescence bands both originate from local/global minima from the lowest triplet excited state (T1). The reported molecular construct serves as an intermediary case between a fully conjugated donor-acceptor system and a donor/acceptor binary mix, which may provide important clues on the design and control of high-freedom molecular systems with complex excited-state dynamics.

scholarly journals The effects of Lactococcus lactis subsp. lactis and its supernatant on some bacteriological and sensory values in Rainbow trout (Onchorhynchus mykiss) fillets

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Asad Abbaspour Anbi ◽  
Vadood Razavilar ◽  
Moslem Neyriz Naghadehi ◽  
Masoud Seidgar ◽  
Ali Nekuiefard ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Lactococcus Lactis ◽  
Storage Time ◽  
Culture Medium ◽  
Live Cells ◽  
Human Consumption ◽  
Lactococcus Lactis Subsp ◽  
Live Bacteria ◽  
And Control ◽  
Control Samples

Lactic Acid Bacteria (LAB) have a great potential as bio-preservatives. The live cells and supernatant Lactococcus lactis subsp. lactis induced bacteriological changes in Onchorhynchus mykiss fillet by spray and immersion methods was studied during vacuum- packaged storage at 4 °C for 15 days. 40 kg of O. mykiss were prepared from a culture farm in Oshnavieh (Northwest Iran) and 112 fillet samples (100g) were prepared by aseptic method. L. lactis subsp. lactis (PTCC1336) bacteria was cultured in MRS culture medium. Its supernatant (2%, 4%) was extracted and 106 CFUml-1 dilutions of LAB were prepared and tested on the fillets to enhance their shelf life. All samples were evaluated regarding to growth of psychrotrophic, psychrophilic, mesophilic bacteria, molds and yeasts. Four characteristics including of odor, flavor, texture and color of fillets after and before cooking were evaluated for sensory analysis on days 1, 5, 10 and 15 and compared with control samples. The 4% supernatant and live bacteria were more effective than that of 2% and control (P<0.05). The amounts of corrosive bacteria in 4% and live cells in storage time were less than human consumption limits (7log CFUg-1), whereas in control and 2% supernatant treatments were more than that limits. The results showed that increasing the percentage of supernatant was more effective on bacteriologic factors and enhanced sensory characteristics of rainbow trout fillets (P<0.05).

scholarly journals Coronary flow in a perfused rainbow trout heart

1987 ◽  
Vol 129 (1) ◽  
pp. 107-123 ◽  
Author(s):  
A. P. Farrell
Keyword(s):  
Rainbow Trout ◽  
Coronary Flow ◽  
Coronary Circulation ◽  
Coronary Vessels ◽  
Cardiac Metabolism ◽  
Salmo Gairdneri ◽  
Acclimation Temperature ◽  
Coronary Vascular Resistance ◽  
Coronary Resistance ◽  
Temperature Dependent

A preparation was developed to perfuse the coronary circulation in working hearts from rainbow trout (Salmo gairdneri Richardson). The preparation was used to examine pressure-flow relationships for the coronary circulation as the heart generated physiological and subphysiological work loads. Coronary vascular resistance increased exponentially as coronary flow rate decreased. Coronary resistance was also influenced by cardiac metabolism and acclimation temperature. When heart rate was increased, extravascular compression increased in coronary resistance. Direct vasoconstriction of the coronary vessels, produced by injections of adrenaline into the coronary circulation, was temperature-dependent.

Catecholamine elevation in iron deficiency

1979 ◽  
Vol 237 (5) ◽  
pp. R297-R300 ◽  
Author(s):  
E. Dillmann ◽  
D. G. Johnson ◽  
J. Martin ◽  
B. Mackler ◽  
C. Finch
Keyword(s):  
Body Temperature ◽  
Body Temperatures ◽  
Temperature Dependent ◽  
Urinary Catecholamines ◽  
Threefold Increase ◽  
Iron Deficient ◽  
Catecholamine Response ◽  
The Difference ◽  
And Control ◽  
Maintain Body Temperature

Iron-deficient rats have increased blood and urinary catecholamines regardless of whether anemia is or is not present. The catecholamine response in both iron-deficient and control animals is largely temperature dependent, showing little difference at the isothermic temperature of 30 degrees C but a two- to threefold increase in iron-deficient animals over controls at lower temperatures. The iron-deficient rat is unable to maintain body temperature at 4 degrees C and this is independent of anemia or of food intake. When animals are run on the treadmill for 4 h, body temperatures increase but the difference observed at 4 degrees C between iron-deficient and control animals persists. The underlying abnormality in temperature regulation and in catecholamine response disappeared after 6 days of iron therapy.

scholarly journals Improvements in Multilayer Ceramic Capacitors

1983 ◽  
Vol 11 (1) ◽  
pp. 53-64 ◽  
Author(s):  
A. F. Dyson
Keyword(s):  
Integrated Circuit ◽  
Cost Reduction ◽  
Random Access ◽  
Multilayer Ceramic Capacitors ◽  
Ceramic Capacitors ◽  
Testing Techniques ◽  
Multilayer Ceramic ◽  
Market Requirement ◽  
And Control ◽  
Critical Process

The increased use of Multilayer Ceramic Capacitors in both chip and encapsulated formats is mainly due to their excellence at decoupling Integrated Circuit Random Access Memories.As a result of this excellent performance, large volumes of this type of capacitor are currently used and indications are that further increases in volume will continue over the next decade. There is therefore a market requirement for continued improvements in performance, reliability and cost.There have been major processing changes for cost reduction reasons, which have resulted in new dielectric systems, changes in electrode types and greatly reduced dielectric thicknesses.Studies of the failure mechanisms in these capacitors have been made, and this paper outlines the effect of process and materials on the reliability of these capacitors.In addition, critical process stages are highlighted and control levels indicated. Some new work on testing techniques and its relevance to delaminations is also reported.

An improved and robust scale-up process aided with identification and control of critical process impurities in darunavir ethanolate

2019 ◽  
Vol 46 (1) ◽  
pp. 267-281
Author(s):  
Sathyanarayana Girigani ◽  
Harnam Singh ◽  
Sankar Rao Kola ◽  
Vijayalaxmi Dayanand Yelmeli ◽  
Venu Gopal Regula ◽  
...  
Keyword(s):  
Scale Up ◽  
Darunavir Ethanolate ◽  
And Control ◽  
Critical Process

Identification and Control of Critical Process Impurities: An Improved Process for the Preparation of Dolutegravir Sodium

2016 ◽  
Vol 20 (8) ◽  
pp. 1461-1468 ◽  
Author(s):  
Srimurugan Sankareswaran ◽  
Madhavarao Mannam ◽  
Veerababu Chakka ◽  
Srirami Reddy Mandapati ◽  
Pramod Kumar
Keyword(s):  
And Control ◽  
Critical Process
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