Thermal tolerance, metabolic scope and performance of meagre, Argyrosomus regius, reared under high water temperatures

2021 ◽  
pp. 103063
Author(s):  
Orestis Stavrakidis-Zachou ◽  
Konstadia Lika ◽  
Pavlidis Michail ◽  
Aleka Tsalafouta ◽  
Asaad H. Mohamed ◽  
...  
Keyword(s):  
Thermal Tolerance ◽  
High Water ◽  
Metabolic Scope ◽  
Argyrosomus Regius ◽  
And Performance

scholarly journals Are Microplastics Impairing Marine Fish Larviculture?—Preliminary Results with Argyrosomus regius

Water ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 104
Author(s):  
Diana Campos ◽  
Andreia C. M. Rodrigues ◽  
Rui J. M. Rocha ◽  
Roberto Martins ◽  
Ana Candeias-Mendes ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Fish Larvae ◽  
Feeding Activity ◽  
Early Ontogeny ◽  
Antioxidant Defenses ◽  
Nutritional Requirements ◽  
Larval Feeding ◽  
Argyrosomus Regius ◽  
And Performance ◽  
Aquaculture Facilities

The presence of small-sized (<300 µm) microplastics (MPs) in aquaculture facilities may threaten finfish hatchery, as their (in)voluntary ingestion by fish larvae may compromise nutritional requirements during early ontogeny, and consequently larval health and performance. Thus, we addressed the short-term effects (7 h) of polyethylene microplastics (0.1, 1.0, 10 mg/L, PE-MPs) in meagre larvae Argyrosomus regius (15 dph) in the presence/absence of food. Larval feeding behavior, oxidative stress status, neurotoxicity, and metabolic requirements were evaluated. Results showed that meagre larvae ingested PE-MPs regardless of their concentration, decreasing in the presence of food (Artemia metanauplii). The presence of PE-MPs compromised larval feeding activity at the highest concentration. Under starvation, exposed larvae activated the antioxidant defenses by increasing the total glutathione levels and inhibiting catalase activity, which seemed efficient to prevent oxidative damage. Such larvae also presented increased energy consumption potentially related to oxidative damage prevention and decreased neurotransmission. Biochemical responses of fed larvae showed a similar trend, except for LPO, which remained unaffected, except at 0.1 mg/PE-MPs/L. Our results suggest that small-sized MPs in finfish hatcheries may compromise larvae nutritional requirements, but at considerably higher levels than those reported in marine environments. Nevertheless, cumulative adverse effects due to lower MPs concentrations may occur.

scholarly journals Partitioning the metabolic scope: the importance of anaerobic metabolism and implications for the oxygen- and capacity-limited thermal tolerance (OCLTT) hypothesis

2016 ◽  
Vol 4 (1) ◽  
pp. cow019 ◽  
Author(s):  
Rasmus Ejbye-Ernst ◽  
Thomas Y. Michaelsen ◽  
Bjørn Tirsgaard ◽  
Jonathan M. Wilson ◽  
Lasse F. Jensen ◽  
...  
Keyword(s):  
Thermal Tolerance ◽  
Anaerobic Metabolism ◽  
Metabolic Scope

Design and performance analysis of novel multiphase induction motor with die-cast copper rotors using FEA for electric propulsion vehicles applications

Circuit World ◽  
2020 ◽  
Vol 46 (4) ◽  
pp. 271-280
Author(s):  
Sathishkumar Kaliyavarathan ◽  
Sivakumaran T.S.
Keyword(s):  
Induction Motor ◽  
Thermal Tolerance ◽  
Electric Propulsion ◽  
Prototype Model ◽  
Additional Advantage ◽  
Content Type ◽  
Modified Method ◽  
Die Cast ◽  
Current Scenario ◽  
And Performance

Purpose The purpose of this paper is to study the development of novel multiphase induction motor (MPIM) with copper die cast rotor in the drive system of electric propulsion vehicles (EPV). It is estimated that the manufacturers are concerned about high torque,Efficiency, motor life, energy conservation and high thermal tolerance. To ensure maximum torque and efficiency with multiphase winding and copper die cast technology to increasing high thermal tolerance, life, energy conversations. On other hand, it is very important of EPV application. Design/methodology/approach The focus of the investigation is threefold: the modified method carried out on MPIM both stator and rotor can overcome the current scenario problem facing by electric vehicles manufacture and developed perfect suitable electric motor for EPV applications. The design and simulation carried out finite element method (FEM) that was more accurate calculations. Finally developed prototype model of MPIM with copper die cast are discussed with conventional three phase Die casting Induction motor. Findings The paper confirmed the multiphase copper die-cast rotor induction motor (MDCrIM) is providing better performance than conventional motor. Proposed motor can bring additional advantage like heat tolerances, long life and energy conversations. Originality/value The experiments confirmed the MDCIM suitable for EPV Applications. The modified MDCIM of both stator and rotor are giving better result and good performance compared to conventional method.

The Construction and Calibration of an electrical Hygrometer suitable for Microclimatic Measurements

1953 ◽  
Vol 44 (2) ◽  
pp. 333-342 ◽  
Author(s):  
E. B. Edney
Keyword(s):  
Mass Production ◽  
High Water ◽  
Glass Wool ◽  
Dew Point ◽  
Saturation Point ◽  
Water Vapour Content ◽  
Fibre Glass ◽  
Nickel Iron ◽  
And Performance ◽  
Made In

The paper describes the construction, calibration and performance of an electrolytic hygrometer based on the principle of the “Gregory” hygrometer, but considerably smaller. Its dimensions are about 6×6×10 mm.The element consists of two platinum-clad nickel-iron electrodes, holding a spiral of continuous fibre-glass wool yarn which is impregnated with a solution of calcium chloride. The water content of this hygroscopic salt varies with humidity, so that the resistance between the two electrodes also varies. In order to measure this resistance, alternating current of a known voltage is used, and the current is measured in terms of micro-amperes. A suitable circuit is described. Air temperature is measured by a fine thermocouple permanently attached to each element.Long exposure to air above acid and water mixtures damages the elements so that calibration is best carried out without acid. An apparatus in which this can be done is described. A stream of air with a high water vapour content is cooled to a precisely known temperature which is below its saturation point, and then raised to the temperature required for calibration, so that its relative humidity is known as it passes over the element being calibrated. Finally the dew-point is again found as a check. Temperature affects the resistance of the elements, and calibration must therefore be carried out at three different constant temperatures.Curves obtained by means of this apparatus show that one element will give readings from 50 to 98 per cent. R.H. within ±2 per cent. Another element with more hygroscopic salt must be used for humidities between 60 and 10 per cent. R.H.There is an ageing process whereby the resistance of each element increases for some time after it has been constructed. This period can be shortened by exposing the elements to alternating high and low humidities for a few days. Elements which have received this treatment can be calibrated and used after six weeks, and will remain in calibration for at least a fortnight.Subsequent calibrations can be made in a simple apparatus (which is described) involving acid-and-water mixtures, but the use of filters and exposure of the elements for no more than 15 minutes avoids damage.The hygrometer equilibrates in a new humidity within ten minutes.The instruments possess certain advantages: they are small, they can be read or recorded at a distance, and they do not depend upon evaporation of water, so that disturbance of the natural environment is minimised. The main disadvantages are that they cannot be exposed to saturated air without going out of calibration and that each instrument must be calibrated individually—they cannot easily be standardised for mass production.

Ontogenetic thermal tolerance and performance of ectotherms at variable temperatures

2016 ◽  
Vol 29 (7) ◽  
pp. 1462-1468 ◽  
Author(s):  
G. Cavieres ◽  
J. M. Bogdanovich ◽  
F. Bozinovic
Keyword(s):  
Thermal Tolerance ◽  
And Performance

scholarly journals Improved heat tolerance in air drives the recurrent evolution of air-breathing

2014 ◽  
Vol 281 (1782) ◽  
pp. 20132927 ◽  
Author(s):  
Folco Giomi ◽  
Marco Fusi ◽  
Alberto Barausse ◽  
Bruce Mostert ◽  
Hans-Otto Pörtner ◽  
...  
Keyword(s):  
Thermal Tolerance ◽  
Evolutionary Biology ◽  
High Water ◽  
Aerobic Performance ◽  
Air Breathing ◽  
Thermal Niche ◽  
Key Innovation ◽  
Animal Phyla ◽  
The Tropics ◽  
Environmental Temperatures

The transition to air-breathing by formerly aquatic species has occurred repeatedly and independently in fish, crabs and other animal phyla, but the proximate drivers of this key innovation remain a long-standing puzzle in evolutionary biology. Most studies attribute the onset of air-breathing to the repeated occurrence of aquatic hypoxia; however, this hypothesis leaves the current geographical distribution of the 300 genera of air-breathing crabs unexplained. Here, we show that their occurrence is mainly related to high environmental temperatures in the tropics. We also demonstrate in an amphibious crab that the reduced cost of oxygen supply in air extends aerobic performance to higher temperatures and thus widens the animal's thermal niche. These findings suggest that high water temperature as a driver consistently explains the numerous times air-breathing has evolved. The data also indicate a central role for oxygen- and capacity-limited thermal tolerance not only in shaping sensitivity to current climate change but also in underpinning the climate-dependent evolution of animals, in this case the evolution of air-breathing.

scholarly journals Assessment of the Performance of Rainfall-Runoff Model GR4J to Simulate Streamflow in Ouémé Watershed at Bonou’s outlet (West Africa)

2018 ◽  
Author(s):  
Domiho Japhet Kodja ◽  
Gil Mahé ◽  
Ernest Amoussou ◽  
Michel Boko ◽  
Jean-Emmanuel Paturel
Keyword(s):  
Climate Change ◽  
High Water ◽  
High Flow ◽  
Performance Criteria ◽  
Rainfall Runoff ◽  
Flow Rates ◽  
Water Flows ◽  
Rainfall Runoff Model ◽  
And Performance ◽  
Runoff Model

The study aims to analyze the performance criteria of the GR4J model to reproduce high water flows in the Ou&eacute;m&eacute; watershed at Bonou's outlet which has been vulnerable to climate change in recent decades. The methodology focused on the use of daily climatological and hydrometric data extracted from files of National Directorate of Meteorology, and General Directorate of Water; they were supplemented by those of SIEREM/HSM dataset over the period 1961-2015. The rainfall was regionalized using Thiessen method. The performance of the GR4J model was assessed with NSE, RMSE and KGE criteria. The results indicate that the study area is marked by rainfall variabilities and detection of two breakpoints (1968 and 1987) which divide the series into three sub-periods; these discontinuities have repercussions on the streamflow. It's found that GR4J model overestimates the streamflow during the low water period and underestimates them in high water. However, the efficiency and performance criteria NSE, RMSE and KGE calculated on high water flow rates are better in calibration than in validation. The KGE values are range between 83-85% in calibration and 56-68% during validation, which gives to GR4J model the efficiency and performance to reproduce high flow rates in the study area

scholarly journals Emerging technology approach for extractability and stability of betalains from the peel of beetroot (Beta vulgaris L.)

2021 ◽  
Author(s):  
Moh Moh Zin ◽  
Szilvia Bánvölgyi
Keyword(s):  
Thermal Tolerance ◽  
Thermal Instability ◽  
Functional Foods ◽  
Arrhenius Equation ◽  
Pure Water ◽  
High Water ◽  
Processing Conditions ◽  
Microwave Assisted ◽  
Water Solvent ◽  
Assisted Extraction

AbstractBetalains are natural color compounds with high water affinity, unstable, and fragile; hence, understanding their thermal tolerance is always beneficial either in manufacturing them or in their application in betalain-rich functional foods for better handling. In our study, the extractability of betalains via microwave-assisted extraction (MAE) from the peel of beetroot was implemented at 100–800 W for 30–150 s with four different solvents. Among the maximum amounts of total betalains (202.08 ± 2.23 mg/100 g FW), betacyanin (115.89 ± 1.08 mg/100 g FW) and betaxanthin (86.21 ± 1.16 mg/100 g FW) were generated by pure water solvent after 150 s of MAE at 800 W. Alternatively, the susceptibility of beetroot peel extracts to processing conditions was investigated by heating them at 30–70 °C, and the thermal instability of betalains was evaluated by half-life (t1/2), temperature quotient (Q10), and activation energy (Ea), using the Arrhenius equation. The resulted retention percentage (R%) proved that ascorbic acid improved the R% of total betalains from 22 to 51% and betacyanin from 3 to 29% and in contrast reduced R% of betaxanthin from 56 to 40% after the heat treatment at 70 °C for 5 h.

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