scholarly journals Conflict and Compromise: Using Reversible Remodeling to Manage Competing Physiological Demands at the Fish Gill

Physiology ◽  
2018 ◽  
Vol 33 (6) ◽  
pp. 412-422 ◽  
Author(s):  
Kathleen M. Gilmour ◽  
Steve F. Perry
Keyword(s):  
High Temperature ◽  
Oxygen Uptake ◽  
Surface Area ◽  
Oxygen Demand ◽  
Structural Features ◽  
Functional Surface ◽  
Fish Gill ◽  
Gill Remodeling ◽  
Physiological Demands ◽  
Passive Movements

The structural features of the fish gill necessary for oxygen uptake also favor undesirable, passive movements of ions and water. Reversible gill remodeling is one solution to this conflict. Cell masses that limit functional surface area are lost when oxygen availability decreases in hypoxia or oxygen demand increases with exercise or high temperature. However, much remains to be learned about how widespread reversible gill remodeling is among fish species, and how and why it occurs.

Structural features and enhanced high-temperature oxygen ion transport in SrFe1−xTaxO3−δ

2013 ◽  
Vol 197 ◽  
pp. 191-197 ◽  
Author(s):  
Alexey A. Markov ◽  
Elizaveta V. Shalaeva ◽  
Alexander P. Tyutyunnik ◽  
Vasily V. Kuchin ◽  
Mikhail V. Patrakeev ◽  
...  
Keyword(s):  
High Temperature ◽  
Ion Transport ◽  
Structural Features ◽  
Oxygen Ion

Structural deformation-metamorphism and exhumation processes of Yuanmou metamorphic complex, Yunnan, China

2021 ◽  
Author(s):  
Xuemei Cheng ◽  
Shuyun Cao
Keyword(s):  
High Temperature ◽  
Electron Backscatter Diffraction ◽  
Early Stage ◽  
Structural Features ◽  
Detachment Fault ◽  
Ductile Deformation ◽  
Structural Deformation ◽  
Subsequent Stage ◽  
Metamorphic Complex ◽  
South Central

<p>Within orogenic zone and continental extensional area, it often developed metamorphic complex or metamorphic gneiss dome that widely exposed continental mid-lower crustal rocks, which is an ideal place to study exhumation processes of deep-seated metamorphic complex and rheology. The Yuanmou metamorphic complex is located in the south-central part of the "Kangdian Axis" in the western margin of Qiangtang Block and Yangtze Block, which is a part of the anticline of the Sichuan-Yunnan platform. Many research works mainly focus on the discussion of intrusion ages, aeromagnetic anomalies, and polymetallic deposits. However, the exhumation process and mechanism of the Yuanmou metamorphic complex are rarely discussed and still unclear. This study, based on detailed field geological observations, optical microscopy (OM), cathodoluminescence (CL), electron backscatter diffraction (EBSD) and electron probe (EMPA) were performed to illustrate the geological structure features, deformation-metamorphic evolution process and its tectonic significance of Yuanmou metamorphic complex during the exhumation process. All these analysis results indicate that the Yuanmou metamorphic complex generally exhibits a dome structure with deep metamorphic rocks and deformed rocks of varying degrees widely developed. Mylonitic gneiss and granitic intrusions are located in the footwall of the Yuanmou, which have suffered high-temperature shearing. The mylonitic fabrics and mineral stretching lineations in the deformed rock are strongly developed, forming typical S-L or L-shaped structural features. The high-temperature ductile deformation-metamorphism environment is high amphibolite facies, that is, the temperature range is between 620 ~ 690 ℃ and the pressure is between 0.8 ~ 0.95 Gpa. In the deformed rocks closed to the detachment fault, some of the mylonite fabric features are retained, but most of them have experienced a strongly overprinted retrogression metamorphism and deformation. At the top of the detachment fault zone, it is mainly composed of cataclasites and fault gouge. The comprehensive macro- and microstructural characteristics, geometry, kinematics, and mineral (amphibole, quartz and calcite) EBSD textures indicate that the Yuanmou metamorphic complex has undergone a progressive exhumation process during regional extension, obvious high-temperature plastic deformation-metamorphism in the early stage, and superimposed of low-temperature plastic-brittle and brittle deformation in the subsequent stage, which is also accompanied by strong fluid activities during the exhumation process.</p>

scholarly journals Assessment of oxygen-uptake efficiency slope in healthy children and children with heart disease: Generation of appropriate reference values for the OUES variable

2018 ◽  
Vol 26 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Carlos AC Hossri ◽  
Isabela PM Alves de Souza ◽  
Joana ST de Oliveira ◽  
Luiz E Mastrocola
Keyword(s):  
Heart Disease ◽  
Oxygen Uptake ◽  
Children And Adolescents ◽  
Surface Area ◽  
Reference Values ◽  
Functional Capacity ◽  
Body Surface ◽  
Congenital Heart ◽  
Reference Value ◽  
Oxygen Uptake Efficiency Slope

Background Oxygen-uptake efficiency slope (OUES) is an objective measure of functional capacity that does not require a maximal effort but is considerably dependent on anthropometric variables and requires the generation of an appropriate reference value in children. This study aimed to establish normal reference values for OUES/kg in children with and without congenital heart diseases. Besides that, reference values are presented secondarily for OUES per body surface area (OUES/BSA). Design Cross-sectional. Methods Six hundred and seventy-six children and adolescents performed a maximal cardiopulmonary exercise test (305 healthy controls and 371 individuals with congenital heart defect), between four and 21 years old (481 males and 195 females, with a mean age of 12 years). Results The OUES reference value for the classification of children and adolescents with normal functional capacity (>80% of predicted maximum oxygen uptake) was 34.63 (sensitivity 77% and specificity 83%, p < 0.05). Regarding the body surface area, considering healthy patients and those with heart disease, the cutoff value of the OUES/BSA was 1151 with sensitivity of 79% and specificity of 79%. Conclusions OUES/kg may be an important marker tool in the differentiation between preserved or abnormal functional capacity in children and adolescents with and without congenital heart disease, even at the submaximal level of exercise.

Thermal expansion and high temperature structural features of the filled skutterudite Sm β (Fe α Ni 1-α ) 4 Sb 12

2017 ◽  
Vol 87 ◽  
pp. 31-37 ◽  
Author(s):  
Cristina Artini ◽  
Carlo Fanciulli ◽  
Gilda Zanicchi ◽  
Giorgio Andrea Costa ◽  
Riccardo Carlini
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Structural Features ◽  
Filled Skutterudite

Inosose-Flüssigkristalle / Inosose Liquid Crystals

1990 ◽  
Vol 45 (7) ◽  
pp. 1084-1090 ◽  
Author(s):  
Klaus Praefcke ◽  
Bernd Kohne ◽  
Andreas Eckert ◽  
Joachim Hempel
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
High Temperature ◽  
Liquid Crystalline ◽  
Structural Features ◽  
Lyotropic Liquid Crystal ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Alkyl Chains

Six S,S-dialkyl acetals 2a-f of inosose (1), tripodal in structure, have been synthesized, characterized and investigated by optical microscopy and differential scanning calorimetry (d.s.c.). The four S,S-acetals 2c-f with sufficiently long alkyl chains are thermotropic liquid crystalline; 2 e and 2 f are even dithermomesomorphic. Each of these four inosose derivatives 2c-f exhibits monotropically a most likely cubic mesophase (MI); in addition 2e and 2f show enantiotropically a hexagonal mesophase (Hx) with a non-covalent, supramolecular H-bridge architecture. Whereas the nature of the optically isotropic mesophase MI needs further clarification the stable high temperature mesophase Hx of 2 e and 2 f has been established by a miscibility test using a sugar S,S-dialkyl acetal also tripodal in structure and with a Hx phase proved by X-ray diffraction, but in contrast to 2 with an acyclic hydrophilic part. Similarities of structural features between the Hx-phases of 2e and 2f as well as of other thermotropic and lyotropic liquid crystal systems are discussed briefly.

scholarly journals Efficient hyperparameter-tuned machine learning approach for estimation of supercapacitor performance attributes

2021 ◽  
Author(s):  
Syed Ishtiyaq Ahmed ◽  
Sreevatsan Radhakrishnan ◽  
Binoy B Nair ◽  
Rajagopalan Thiruvengadathan
Keyword(s):  
Machine Learning ◽  
Surface Area ◽  
Computational Models ◽  
Performance Metrics ◽  
Structural Features ◽  
Optimization Techniques ◽  
Storage Device ◽  
Micropore Surface Area ◽  
Supercapacitor Performance ◽  
Carbon Based

Abstract Recent years have witnessed the rise of supercapacitor as effective energy storage device. Specifically, carbon-based electrodes have been experimentally well studied and used in the fabrication of supercapacitors due to their excellent electrochemical properties. This work reports the development and utilization of highly tuned and efficient Machine Learning (ML) models that give insights into correlation between structural features of electrodes and supercapacitor performance metrics namely specific capacitance, power density and energy density. Artificial Neural Networks (ANN) and Random Forest (RF) models have been employed to predict the various in-operando performance metrics of carbon-based supercapacitors based on three input features such as mesopore surface area, micropore surface area and scan rate. Experimentally measured values of these parameters used for training and testing these two models have been extracted from a set of research papers reported in literature. The optimization techniques and various tuning methodologies adopted for identifying model hyperparameters are discussed in this paper. The authors demonstrate the importance of hyperparameter tuning and optimization in building accurate and reliable computational models.

scholarly journals Game Intensity Analysis of Elite Adolescent Ice Hockey Players

2014 ◽  
Vol 44 (1) ◽  
pp. 211-221 ◽  
Author(s):  
Arkadiusz Stanula ◽  
Robert Roczniok
Keyword(s):  
Oxygen Uptake ◽  
Ice Hockey ◽  
Maximal Heart Rate ◽  
Mean Values ◽  
National Team ◽  
Hockey Players ◽  
Physiological Demands ◽  
The Difference ◽  
Uptake Test ◽  
Aerobic And Anaerobic

Abstract The purpose of this study was to determine ice-hockey players’ playing intensity based on their heart rates (HRs) recorded during a game and on the outcomes of an incremental maximum oxygen uptake test. Twenty ice-hockey players, members of the Polish junior national team (U18), performed an incremental test to assess their maximal oxygen uptake (V̇ O2max) in the two week’s period preceding 5 games they played at the World Championships. Players’ HRs at the first and second ventilatory thresholds obtained during the test were utilized to determine intensity zones (low, moderate, and high) that were subsequently used to classify HR values recorded during each of the games. For individual intensity zones, the following HRs expressed as mean values and as percentages of the maximal heart rate (HRmax) were obtained: forwards 148-158 b⋅min-1 (79.5-84.8% HRmax), 159-178 b⋅min-1 (85.4-95.6% HRmax), 179-186 b⋅min-1 (96.1-100.0% HRmax); defensemen 149-153 b⋅min-1 (80.0-82.1% HRmax), 154-175 b⋅min-1 (82.6- 94.0% HRmax), 176-186 b⋅min-1 (94.5-100.0% HRmax). The amount of time the forwards and defensemen spent in the three intensity zones expressed as percentages of the total time of the game were: 54.91 vs. 55.62% (low), 26.40 vs. 22.38% (moderate) and 18.68 vs. 22.00% (high). The forwards spent more time in the low intensity zone than the defensemen, however, the difference was not statistically significant. The results of the study indicate that using aerobic and anaerobic metabolism variables to determine intensity zones can significantly improve the reliability of evaluation of the physiological demands of the game, and can be a useful tool for coaches in managing the training process.

Sign in / Sign up

Export Citation Format

Share Document