scholarly journals Thermal performance of fish is explained by an interplay between physiology, behaviour and ecology

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Philipp Neubauer ◽  
Ken H Andersen
Keyword(s):  
Thermal Performance ◽  
Null Model ◽  
Oxygen Limitation ◽  
Driving Mechanism ◽  
Metabolic Rates ◽  
Metabolic Scope ◽  
And Function ◽  
Temperature Impacts ◽  
Term Performance ◽  
Species Ecology

Abstract Increasing temperatures under climate change are thought to affect individual physiology of fish and other ectotherms through increases in metabolic demands, leading to changes in species performance with concomitant effects on species ecology. Although intuitively appealing, the driving mechanism behind thermal performance is contested; thermal performance (e.g. growth) appears correlated with metabolic scope (i.e. oxygen availability for activity) for a number of species, but a substantial number of datasets do not support oxygen limitation of long-term performance. Whether or not oxygen limitations via the metabolic scope, or a lack thereof, have major ecological consequences remains a highly contested question. size and trait-based model of energy and oxygen budgets to determine the relative influence of metabolic rates, oxygen limitation and environmental conditions on ectotherm performance. We show that oxygen limitation is not necessary to explain performance variation with temperature. Oxygen can drastically limit performance and fitness, especially at temperature extremes, but changes in thermal performance are primarily driven by the interplay between changing metabolic rates and species ecology. Furthermore, our model reveals that fitness trends with temperature can oppose trends in growth, suggesting a potential explanation for the paradox that species often occur at lower temperatures than their growth optimum. Our model provides a mechanistic underpinning that can provide general and realistic predictions about temperature impacts on the performance of fish and other ectotherms and function as a null model for contrasting temperature impacts on species with different metabolic and ecological traits.

scholarly journals Thermal performance of fish is explained by an interplay between physiology, behaviour, and ecology

2018 ◽  
Author(s):  
Philipp Neubauer ◽  
Ken H. Andersen
Keyword(s):  
Thermal Performance ◽  
Null Model ◽  
Oxygen Limitation ◽  
Driving Mechanism ◽  
Metabolic Rates ◽  
Metabolic Scope ◽  
And Function ◽  
Temperature Impacts ◽  
Term Performance ◽  
Species Ecology

Increasing temperatures under climate change are thought to affect individual physiology of fish and other ectotherms through increases in metabolic demands, leading to changes in species performance with concomitant effects on species ecology. Although intuitively appealing, the driving mechanism behind thermal performance is contested: thermal performance (e.g., growth) appears correlated with metabolic scope (i.e., oxygen availability for activity) for a number of species, but a substantial number of datasets do not support oxygen limitation of long-term performance. Whether or not oxygen limitations via the metabolic scope, or a lack thereof, have major ecological consequences remains a highly contested question. Here, we propose a general size and trait-based model of energy and oxygen budgets to determine the relative influence of metabolic rates, oxygen limitation, and environmental conditions on ecotherm performance. We show that oxygen limitation is not necessary to explain performance variation with temperature. Oxygen can drastically limit performance and fitness, especially at temperature extremes, but changes in thermal performance are primarily driven by the interplay between changing metabolic rates and species ecology. Furthermore, our model reveals that fitness trends with temperature can oppose trends in growth, suggesting a potential explanation for the paradox that species often occur at lower temperatures than their growth-optimum. Our model provides a mechanistic underpinning that can provide general and realistic predictions about temperature impacts on the performance of fish and other ectotherms, and function as a null model for contrasting temperature impacts on species with different metabolic and ecological traits.

The heart as a functional unit

ESC CardioMed ◽  
2018 ◽  
pp. 76-81
Author(s):  
Philip J. Kilner ◽  
Sonya V. Babu-Narayan
Keyword(s):  
Functional Unit ◽  
Structure And Function ◽  
Morphological Features ◽  
Metabolic Rates ◽  
Evolutionary Origins ◽  
And Function

This chapter and Chapter 3.6 address the interrelatedness of heart form, structure, and function. The principle of reciprocation between the alternate contractions of atrial and ventricular cavities is outlined, and it is explained how it is enhanced with the increased output of exercise by virtue of the directions of the forces associated with changes of momentum through the looped curvatures of the heart. The human heart’s sinuous paths of flow and its fully septated, four-chamber arrangement are features shared by the hearts of other mammals and the birds, which are also warm-blooded with relatively high cardiac outputs for high metabolic rates. These morphological features are not found among the hearts of the exothermic invertebrate phyla such as worms, arthropods, or molluscs. The possible evolutionary origins and potential functional advantages of cardiac septation for mammalian life are considered. This chapter addresses the interrelatedness of macroscopic structural morphodynamics with the fluid morphodynamics of passing blood streams while Chapter 3.6 considers the smaller-scale morphodynamics of myocardium in an attempt to convey a multiscale morphodynamic interpretation of the heart form, structure, and function.

Research on Modes and Operating Mechanism of Informal Finance

2014 ◽  
Vol 926-930 ◽  
pp. 3898-3901
Author(s):  
Shou Bin Zhou ◽  
Pei Zhou
Keyword(s):  
Central Government ◽  
Developed Countries ◽  
Market Mechanism ◽  
Coordination Mechanism ◽  
Driving Mechanism ◽  
Operating Mechanism ◽  
Informal Finance ◽  
Operational Mechanism ◽  
Capital Efficiency ◽  
And Function

Informal finance exists in developed countries and in developing countries, the form of informal finance is diversiform, but operational mechanism of informal finance is essentially similar. Nowadays, in china informal finance’s contribution for whole macro economy is bigger and bigger, but up to the present our central government has not established the interrelated policies and regulations in order to make informal finance legal and rational. In order to make them support the whole macro economy better and make different regions choose suited modes among the different forms of informal finance, this paper study on the informal finance’s modes and operating mechanism from driving mechanism-interest rate mechanism, coordination mechanism-financing method, operating principle, controlling mechanism, security mechanism-withdrawing market mechanism in order to improve further collocating-capital efficiency and function for economic development positively.

scholarly journals Universal rules of life: metabolic rates, biological times and the equal fitness paradigm

2021 ◽  
Author(s):  
Joseph Burger ◽  
Chen Hou ◽  
Charles Hall ◽  
James Brown
Keyword(s):  
Structure And Function ◽  
The Other ◽  
Metabolic Rates ◽  
Synthetic Theory ◽  
Evolutionary Patterns ◽  
Single Origin ◽  
The One ◽  
Patterns And Processes ◽  
And Function ◽  
Dynamics Of Populations

Here we review and extend the equal fitness paradigm (EFP) as an important step in developing and testing a synthetic theory of ecology and evolution based on energy and metabolism. The EFP states that all organisms are equally fit at steady state, because they allocate the same quantity of energy, ~22.4 kJ/g/generation to production of offspring. On the one hand, the EFP may seem tautological, because equal fitness is necessary for the origin and persistence of biodiversity. On the other hand, the EFP reflects universal laws of life: how biological metabolism – the uptake, transformation and allocation of energy – links ecological and evolutionary patterns and processes across levels of organization from: i) structure and function of individual organisms, ii) life history and dynamics of populations, iii) interactions and coevolution of species in ecosystems. The physics and biology of metabolism have facilitated the evolution of millions of species with idiosyncratic anatomy, physiology, behavior and ecology but also with many shared traits and tradeoffs that reflect the single origin and universal rules of life.

scholarly journals Statistical testing and annotation of gene transcriptomic-neuroimaging associations

2021 ◽  
Author(s):  
Yongbin Wei ◽  
Siemon C. de Lange ◽  
Rory Pijnenburg ◽  
Lianne H. Scholtens ◽  
Dirk Jan Ardesch ◽  
...  
Keyword(s):  
Gene Annotation ◽  
Null Model ◽  
Brain Regions ◽  
Null Models ◽  
Statistical Testing ◽  
Web Based ◽  
Transcriptomic Data ◽  
Brain Structure And Function ◽  
Health And Disease ◽  
And Function

AbstractMultiscale integration of neuroimaging and gene transcriptome is becoming a widely used approach for exploring the molecular pathways of brain structure and function, in health and disease. Statistical testing of associations between spatial patterns of imaging-based phenotypic and transcriptomic data is key in these explorations, in particular establishing that observed associations exceed ‘chance level’ of random, non-specific observations. We discuss options for such statistical evaluations, including commonly applied linear regression, null model based on randomized brain regions that maintain spatial relationships, and null models built upon random effects that occur from other genes. Using examples and simulations of analyses as commonly performed in literature, we explain the caveats of these statistical models and provide guidelines for using proper models to evaluate both spatial and gene specificity. The null models are presented in a web-based application called GAMBA (“Gene Annotation using Macroscale Brain-imaging Association”) that is designed for exploring transcriptomic-neuroimaging associations.

Australasian marsupials - to cherish and to hold

2001 ◽  
Vol 13 (8) ◽  
pp. 477 ◽  
Author(s):  
C. H. Tyndale-Biscoe
Keyword(s):  
Common Factor ◽  
Extended Period ◽  
Low Fertility ◽  
Limited Resources ◽  
Arid Environments ◽  
Metabolic Rates ◽  
Metabolic Scope ◽  
The Common ◽  
Field Metabolic Rates ◽  
Maintenance Requirements

Considerable interchange of mammals between South America and Australasia occurred during the first half of the Tertiary, including the presence of placental mammals in Australia. This challenges the old assumption that the marsupial radiation in Australia was made possible by the absence of placental competition, and suggests that two properties of marsupial organization may have favoured their survival in the increasingly arid climates that developed after the separation of Australasia from Antarctica. The basal metabolic rates of marsupials are about 70% of equivalent placentals, so their maintenance requirements for energy, nitrogen and water are lower, whereas their field metabolic rates are about the same, which means that they have a greater metabolic scope to call on when active. This may have given marsupials an advantage in semi-arid environments. The lengthy and complex lactation of marsupials enables the female to exploit limited resources over an extended period without compromising the survival of the young. Both these properties of marsupials enabled them to survive the double constraints of low fertility soils and the uncertain climate of Australia throughout the Tertiary. The arrival of people was followed first by the extinction of the large marsupials and, much later, by the wholesale decline or extinction of the small-to-medium sized species. The common factor in both extinctions may have been the constraints of marsupial reproduction.

Scaling of osmotic regulation in mammals and birds

1983 ◽  
Vol 244 (5) ◽  
pp. R601-R606 ◽  
Author(s):  
W. A. Calder ◽  
E. J. Braun
Keyword(s):  
Water Balance ◽  
Structure And Function ◽  
Allometric Equations ◽  
Osmotic Regulation ◽  
Metabolic Rates ◽  
Renal Structure ◽  
And Function ◽  
Stressful Environments

Allometric equations provide a means of summarizing and relating the components of renal structure and function in water balance and osmotic regulation. These summary equations also serve as base lines for evaluating adaptations to stressful environments and for comparisons of kidney designs and osmotic strategies of ureotelic mammals and uricotelic birds. Many of the functions can be quantitatively related to the M3/4 scaling of metabolic rates.

scholarly journals Temperature-driven selection on metabolic traits increases the strength of an algal-grazer interaction in naturally warmed streams

2017 ◽  
Author(s):  
C. -Elisa Schaum ◽  
Richard ffrench-Constant ◽  
Chris Lowe ◽  
Jón S Ólafsson ◽  
Daniel Padfield ◽  
...  
Keyword(s):  
Trophic Interactions ◽  
Interaction Strength ◽  
Transplant Experiment ◽  
Ecosystem Structure ◽  
Metabolic Rates ◽  
Reciprocal Transplant Experiment ◽  
Thermal Dependence ◽  
Cold Stream ◽  
And Function ◽  
Warm Stream

ABSTRACTTrophic interactions are important determinants of the structure and functioning of ecosystems. As the metabolism and consumption rates of ectotherms increase sharply with temperature, there are major concerns that global warming will increase the strength of trophic interactions, destabilizing food webs, and altering ecosystem structure and function. We used geothermally warmed streams that span a ∼10°C temperature gradient to investigate the interplay between temperature-driven selection on traits related to metabolism and resource acquisition, and the interaction strength between the keystone gastropod grazer, the wandering snail Radix balthica, and a common algal resource. Populations from a warm stream (∼28°C) had higher maximal metabolic rates and optimal temperatures than their counterparts from a cold stream (∼17°C). We found that metabolic rates of the population originating from a warmer stream were higher across all measurement temperatures. A reciprocal transplant experiment demonstrated that the interaction strengths between the grazer and its algal resource were highest for both populations when transplanted into the warm stream. In line with the thermal dependence of respiration, interaction strengths of grazers from the warm stream were always higher than those of grazers from the cold stream. These findings suggest that warming can increase the strength of algal-grazer interactions through the thermodynamic effects of higher temperatures on physiological rates as well as through correlated increases in per capita metabolism and consumption.

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