Author: Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Physiology in extreme conditions can reveal important reactions of the human body, which help our assessment of limits emerging under healthy conditions and critical signals of transition toward disease. While many mechanisms could simply be associated with adaptations, others refer to unexpected reactions in response to internal stimuli and/or external abrupt changes.
Author: Maria G. Trivella Publisher: Frontiers Media SA ISBN: 2889453383 Category : Languages : en Pages : 135
Book Description
Physiology in extreme conditions can reveal important reactions of the human body, which help our assessment of limits emerging under healthy conditions and critical signals of transition toward disease. While many mechanisms could simply be associated with adaptations, others refer to unexpected reactions in response to internal stimuli and/or external abrupt changes.
Author: European Society for Comparative Physiology and Biochemistry. Conference Publisher: S. Karger AG (Switzerland) ISBN: Category : Medical Languages : en Pages : 240
Author: European Society for Comparative Physiology and Biochemistry. Conference Publisher: ISBN: 9783805544719 Category : Adaptation (Physiology) Languages : en Pages : 240
Author: Costantino Balestra Publisher: Frontiers Media SA ISBN: 2889457400 Category : Languages : en Pages : 229
Book Description
Understanding how humans cope in extreme environments has expanded our knowledge of the physiological and psychological challenges involved and helped us to quit our comfortable paradigms built on “steady states”. Furthermore, measuring our reactions to intermittent stressors and determining the oscillations of our coping mechanisms has led us to unexpected understandings. This methodology has also directly improved our translational or multidisciplinary approach to the subject. Studying healthy individuals in extreme environments could improve our understanding of patients with impaired physiological capacities (who are coping with an environment that becomes extreme to them) and also improve our understanding of physiology and psychology in the elderly.This eBook collects articles that address this translational multidisciplinary approach in an integrative way. As a whole, this Research Topic aims to better understand human/animal physiology and psychology.
Author: Courtney Nicole Passow Publisher: ISBN: Category : Languages : en Pages :
Book Description
Extremophiles are organisms with the ability to survive in environments characterized by strong physicochemical stressors lethal to most other organisms, providing excellent models to further our understanding of life's capacities and limitations to deal with far-from-average conditions. I studied how physiological processes varied among fish residing in starkly different environmental conditions to understand how organisms cope with extreme environments and disentangle the roles of short-term plastic responses and evolved population differences in shaping physiological responses. I used the Poecilia mexicana model, a series of extremophile fish populations that has colonized toxic hydrogen sulfide (H2S) rich springs and caves, to address three major objectives: (1) I investigated the energetic consequences of life in extreme environments and tested whether predicted reductions in organismal energy demands evolved repeatedly along replicated environmental gradients. (2) I characterized variation in gene expression among populations and organs to test for interactive effects between different stressors and identify potential physiological mechanisms underlying adaptation to H2S and cave environments. (3) I conducted common garden and H2S-exposure experiments to test how evolutionary change and plasticity interact to shape variation in gene expression observed in nature. To address these objectives, I measured variation in metabolic physiology and quantified variation in physiological processes through genome-wide gene expression analyses. I found that adaptation to extreme environments directly impacts energy metabolism, with fish living in extreme environments consistently expending less energy overall. Reductions in energy demand have evolved in convergence and were primarily mediated through a life history shift (reduction in body mass). The quantification of gene expression across divergent habitats and organs revealed organ-specific physiological responses in H2S-rich and cave habitats. Gene expression variation in the relevant genes was primarily shaped by evolutionary change in gene regulation, and ancestral plastic responses play a minor role in causing the observed expression differences between replicated sulfidic and nonsulfidic populations in nature. Overall, my research has implications for understanding the capacities and constraints that shape life in extreme environments and aids in our understanding of modifications in physiological pathways mediating adaptation to elevated H2S and perpetual darkness.
Author: Hanns-Christian Gunga Publisher: Academic Press ISBN: 012815943X Category : Science Languages : en Pages : 376
Book Description
Human Physiology in Extreme Environments, Second Edition, offers evidence on how human biology and physiology is affected by extreme environments, also highlighting technological innovations that allow us to adapt and regulate environments. Covering a broad range of extreme environments, including high altitude, underwater, tropical climates, desert climates, arctic climates and space travel, the book also includes case studies that can be used to illustrate practical application. Graduate students, medical students and researchers will find this to be an interesting, informative and useful resource for human physiology, environmental physiology and medical studies. Includes coverage of current global challenges and their consequences on human physiology and performance Presents human physiological challenges in extreme environments Provides an excellent source of information on paleontological and anthropological aspects Offers practical medical and scientific uses of current concepts
Author: Guido di Prisco Publisher: Springer Science & Business Media ISBN: 3642760562 Category : Science Languages : en Pages : 146
Book Description
In their very first lecture biochemists learn that biomolecules, namely nucleic acids, proteins and lipids, are extremely temperature sensitive and will denature and lose their function easily. Then how do Archaebacteria survive in hot springs or Antarctic fishes which live in ice-cold water? The way nature engineered subcellular structures, lipid membranes or proteins to meet the biochemical requirements of extreme conditions - like extreme temperature or salt concentrations - is described in Life Under Extreme Conditions.
Author: Nick Barts Publisher: ISBN: Category : Languages : en Pages :
Book Description
The physiological mechanisms underlying adaptation, and how physiological differences observed in natural populations relate to underlying genetic variation, remain largely unknown for many natural systems. My dissertation seeks to close these gaps in knowledge by addressing three major questions: 1) How does variation across levels of biological organization integrate to explain divergence in organismal phenotypes? 2) Are patterns of physiological adaptation predictable across populations experiencing similar sources of selection? 3) What are the evolutionary origins of physiological traits facilitating adaptation to novel environmental conditions? Organisms inhabiting extreme environments are ideal systems to investigate questions about the mechanisms underlying adaptation and the predictability of evolution at molecular scales. These habitats are characterized by harsh physiochemical stressors that often target specific biochemical and physiological pathways, allowing for hypothesis-driven tests of the effects of the stressor on organismal function and trait evolution. Additionally, powerful comparisons can be made between closely related lineages inhabiting extreme and ancestral habitats, which allows for investigations into the predictability of evolution in response to similar sources of selection. In my research, I leveraged a unique study system of fishes that have independently colonized extreme aquatic habitats rich in hydrogen sulfide (H2S), a naturally occurring toxin that is known to interfere with oxygen transport and mitochondrial function address four objectives: 1) I determined the predictability and repeatability of molecular evolution and changes in gene expression of oxygen transport genes in ten lineages of sulfide-tolerant fishes, 2) I assessed the convergence in biochemical, physiological, and organismal function in pathways exhibiting evidence of molecular evolution and gene expression variation, 3) I measured the functional consequences of genetic variation on the metabolic function of enzymes, mitochondria, and whole organisms to identify the predictability of metabolic evolution across levels of organization and between sulfide-tolerant and -intolerant lineages of fish, and 4) I identified potential adaptive plasticity in gene expression in ancestral freshwater species that may represent pre-adaptations for the colonization of H2S-rich springs. Through the integration of genomic, biochemical, and organismal data, I found that (1) oxygen transport genes are predictable targets of natural selection in sulfide spring fishes, but the modifications in gene expression and sequence variation were not repeatable across groups, (2) both H2S detoxification and oxidative phosphorylation are predictable targets of natural selection in H2S-rich environments, and modification of these integral pathways results in functional differences at the biochemical, physiological, and organismal levels, (3) the degree to which metabolic physiology varies between sulfide-tolerant and -intolerant fish differs depending on the level of organization observed, suggesting that researchers must be cautious when making inferences about function solely from genetic data, and (4) genes exhibiting adaptive plasticity in H2S detoxification, metabolic pathways, and oxygen sensing may have been pre-adaptations that facilitated colonization of sulfide-rich springs. The research detailed in this dissertation has important implications for how scientists perceive the predictability of both evolution and phenotype, highlighting the role environmental and physiological constraints play in our ability to predict the outcomes of natural variation across habitats and within organisms.
Author: 
Author: Maria G. Trivella
Author: European Society for Comparative Physiology and Biochemistry. Conference
Author: European Society for Comparative Physiology and Biochemistry. Conference
Author: Costantino Balestra
Author: Courtney Nicole Passow
Author: Hanns-Christian Gunga
Author: Guido di Prisco
Author: Nick Barts
Author: Guido di Prisco