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International Journal of Molecular... Nov 2022Iron is an indispensable element that participates as an essential cofactor in multiple biological processes. However, when present in excess, iron can engage in redox...
Iron is an indispensable element that participates as an essential cofactor in multiple biological processes. However, when present in excess, iron can engage in redox reactions that generate reactive oxygen species that damage cells at multiple levels. In this report, we characterized the response of budding yeast species from the genus to elevated environmental iron concentrations. We have observed that strains are more resistant to high-iron concentrations than non- species. Liquid growth assays showed that species evolutionarily closer to , such as , , , and , were more resistant to high-iron levels than the more distant species and . Remarkably, strains were especially iron sensitive. Growth assays in solid media suggested that and were more resistant to the oxidative stress caused by elevated iron concentrations. When comparing iron accumulation and sensitivity, different patterns were observed. As previously described for , and particular strains of and became more sensitive to iron while accumulating more intracellular iron levels. However, no remarkable changes in intracellular iron accumulation were observed for the remainder of species. These results indicate that different mechanisms of response to elevated iron concentrations exist in the different species of the genus .
Topics: Saccharomyces; Saccharomyces cerevisiae; Adaptation, Physiological; Acclimatization; Iron
PubMed: 36430442
DOI: 10.3390/ijms232213965 -
Journal of the Royal Society, Interface May 2023Architecture with and from living trees (Baubotanik) is a promising approach to sustainable, climate-adapted construction. Shaping and grafting allows one to create...
Architecture with and from living trees (Baubotanik) is a promising approach to sustainable, climate-adapted construction. Shaping and grafting allows one to create resilient structures that combine the ecological performance and aesthetics of trees with the functions of buildings. In order to design and engineer such living structures, it is necessary to predict the growth of different tree segments, especially when trunks, branches or roots are bent and jointed into a complex inosculated network. To address this, we have developed a tool to forecast the relative girth growth of different segments in such structures based on topological skeletons, the pipe model theory and circuit analogy. We have validated our results with a set of (scaled) photographs of inosculated tree structures of the so-called 'Tree Circus', covering over 80 years of their growth. Our model has proven to predict the relative girth growth with sufficient accuracy for conceptual design purposes. So far, it does not allow the simulation of absolute growth in circumference over the course of time that is necessary to predict quantitative technical aspects, such as mechanical performance at a given time. We conclude by briefly outlining how this could be addressed in future research.
Topics: Acclimatization; Computer Simulation; Dendrites; Plant Roots; Skeleton
PubMed: 37221863
DOI: 10.1098/rsif.2023.0168 -
International Journal of Sports Medicine Nov 1997The importance of oxygen transport and consumption in the body for endurance performance is the reason why altitude training as preparation for competitions at sea level... (Review)
Review
The importance of oxygen transport and consumption in the body for endurance performance is the reason why altitude training as preparation for competitions at sea level has become popular. In hypoxia maximal O2 uptake decreases. Thus for equal work load training at altitude is harder and stimulates adaptation processes more than sea level training. A specific altitude training effect, however, can only be proven if a relative equal load (in % of VO2max) is more effective than during sea level training. In only three of 10 investigations with this design has a significant improvement of either maximal performance, VO2max or endurance been found, in two there was a nonsignificant tendency. When training in hypoxia combined with living in normoxia was investigated two of four groups improved. Living in hypoxia with training in normoxia is probably more effective but only preliminary publications are available. Summarizing, a small specific altitude effect on performance capacity seems to exist, which may be counteracted by negative influences like reduced stimulation of muscular metabolism. A series of single physiological changes at altitude might have positive or negative implications on training success: training of respiratory muscles, increase of hypoxic ventilatory stimulation, reduced heart training by vegetative "braking", increase of red cell and plasma volume (the latter after descent), right shift of the oxygen dissociation curve, increase of oxidative muscle enzymes (only after hypoxia training), shift from fat and muscle glycogen to blood glucose combustion, reduced lactic acid and ammonia production, increase in buffer capacity.
Topics: Acclimatization; Altitude; Biomechanical Phenomena; Blood Volume; Humans; Oxygen; Oxygen Consumption; Physical Education and Training; Physical Endurance; Respiration
PubMed: 9443586
DOI: 10.1055/s-2007-972682 -
Journal of Fish Biology May 2023Critical thermal maxima methodology (CTM) has been used to infer acute upper thermal tolerance in fishes since the 1950s, yet its ecological relevance remains debated.... (Review)
Review
Critical thermal maxima methodology (CTM) has been used to infer acute upper thermal tolerance in fishes since the 1950s, yet its ecological relevance remains debated. In this study, the authors synthesize evidence to identify methodological concerns and common misconceptions that have limited the interpretation of critical thermal maximum (CT ; value for an individual fish during one trial) in ecological and evolutionary studies of fishes. They identified limitations of, and opportunities for, using CT as a metric in experiments, focusing on rates of thermal ramping, acclimation regimes, thermal safety margins, methodological endpoints, links to performance traits and repeatability. Care must be taken when interpreting CTM in ecological contexts, because the protocol was originally designed for ecotoxicological research with standardized methods to facilitate comparisons within study individuals, across species and contexts. CTM can, however, be used in ecological contexts to predict impacts of environmental warming, but only if parameters influencing thermal limits, such as acclimation temperature or rate of thermal ramping, are taken into account. Applications can include mitigating the effects of climate change, informing infrastructure planning or modelling species distribution, adaptation and/or performance in response to climate-related temperature change. The authors' synthesis points to several key directions for future research that will further aid the application and interpretation of CTM data in ecological contexts.
Topics: Animals; Fishes; Temperature; Acclimatization; Biological Evolution; Adaptation, Physiological; Climate Change
PubMed: 36880500
DOI: 10.1111/jfb.15368 -
Ear and Hearing 2021Audiologists and hearing aid users (HAUs) generally agree that an adaptation period is needed following the first hearing aid (HA) experience. The main purpose of this... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
Audiologists and hearing aid users (HAUs) generally agree that an adaptation period is needed following the first hearing aid (HA) experience. The main purpose of this study is to investigate the acclimatization of older adult listeners with hearing loss to HAs using listening effort and behavioral measures.
DESIGN
Participants (N=47) were older adults with mild to moderately severe sensorineural hearing loss. Thirty-two participants were new HAUs and 15 participants were experienced HAUs. New HAUs were randomly assigned to one of two groups: noise reduction algorithms and directional microphones activated or noise reduction algorithms and directional microphones deactivated. Speech recognition in noise and listening effort were assessed on 8 different occasions during a 10-month period. A dual-task paradigm was used to measure the listening effort deployed to recognize speech in noise. The primary task consisted of the Hearing in Noise Test which also served as the behavioral speech in noise measure. The secondary task was a tactile pattern-recognition task in which participants had to identify a sequence of three tactile stimuli that varied in duration. The two listening effort outcomes were the proportional dual-task cost and the response time on the secondary task. Cognitive abilities, including working memory and speed of processing, were evaluated using the Reading Span Test and the Digit Symbol Substitution Test, respectively.
RESULTS
Results show a significant time*group interaction. Both groups of new HAUs showed improvement over time in speech in noise performances (change of ~2 dB signal to noise ratio) and the experienced HAUs did not improve over time. The acclimatization effect was observed over a period of 4 weeks. There was no significant change over time on both measures of listening effort. There was no association between amplitude of acclimatization and the cognitive abilities measured.
CONCLUSION
An acclimatization effect following HA experience was observed. Specifically, the new HAUs displayed a clinically significant change of 2 dB in signal to noise ratio on the Hearing in Noise Test 4 weeks following their initial fitting. The acclimatization effect is not correlated to cognitive abilities.
Topics: Acclimatization; Aged; Hearing Aids; Hearing Loss, Sensorineural; Humans; Noise; Speech Perception
PubMed: 32769437
DOI: 10.1097/AUD.0000000000000913 -
Plant Signaling & Behavior Dec 2024Plants, as sessile organisms, are subjected to diverse abiotic stresses, including salinity, desiccation, metal toxicity, thermal fluctuations, and hypoxia at different... (Review)
Review
Plants, as sessile organisms, are subjected to diverse abiotic stresses, including salinity, desiccation, metal toxicity, thermal fluctuations, and hypoxia at different phases of plant growth. Plants can activate messenger molecules to initiate a signaling cascade of response toward environmental stresses that results in either cell death or plant acclimation. Nitric oxide (NO) is a small gaseous redox-active molecule that exhibits a plethora of physiological functions in growth, development, flowering, senescence, stomata closure and responses to environmental stresses. It can also facilitate alteration in protein function and reprogram the gene profiling by direct or indirect interaction with different target molecules. The bioactivity of NO can be manifested through different redox-based protein modifications including -nitrosylation, protein nitration, and metal nitrosylation in plants. Although there has been considerable progress in the role of NO in regulating stress signaling, still the physiological mechanisms regarding the abiotic stress tolerance in plants remain unclear. This review summarizes recent advances in understanding the emerging knowledge regarding NO function in plant tolerance against abiotic stresses. The manuscript also highlighted the importance of NO as an abiotic stress modulator and developed a rational design for crop cultivation under a stress environment.
Topics: Nitric Oxide; Signal Transduction; Acclimatization; Cell Death; Stress, Physiological
PubMed: 38190763
DOI: 10.1080/15592324.2023.2298053 -
Genes Feb 2019Whether Andean populations are genetically adapted to high altitudes has long been of interest. Initial studies focused on physiological changes in the O₂ transport... (Review)
Review
Whether Andean populations are genetically adapted to high altitudes has long been of interest. Initial studies focused on physiological changes in the O₂ transport system that occur with acclimatization in newcomers and their comparison with those of long-resident Andeans. These as well as more recent studies indicate that Andeans have somewhat larger lung volumes, narrower alveolar to arterial O₂ gradients, slightly less hypoxic pulmonary vasoconstrictor response, greater uterine artery blood flow during pregnancy, and increased cardiac O utilization, which overall suggests greater efficiency of O₂ transfer and utilization. More recent single nucleotide polymorphism and whole-genome sequencing studies indicate that multiple gene regions have undergone recent positive selection in Andeans. These include genes involved in the regulation of vascular control, metabolic hemostasis, and erythropoiesis. However, fundamental questions remain regarding the functional links between these adaptive genomic signals and the unique physiological attributes of highland Andeans. Well-designed physiological and genome association studies are needed to address such questions. It will be especially important to incorporate the role of epigenetic processes (i.e.; non-sequence-based features of the genome) that are vital for transcriptional responses to hypoxia and are potentially heritable across generations. In short, further exploration of the interaction among genetic, epigenetic, and environmental factors in shaping patterns of adaptation to high altitude promises to improve the understanding of the mechanisms underlying human adaptive potential and clarify its implications for human health.
Topics: Acclimatization; Adaptation, Physiological; Altitude; Humans; Hypoxia; Oxygen; Polymorphism, Single Nucleotide; Selection, Genetic
PubMed: 30781443
DOI: 10.3390/genes10020150 -
Planta Jul 2021An overview is presented of recent advances in our knowledge of responses and mechanisms rendering adaptation to saline conditions in sorghum. Different strategies... (Review)
Review
An overview is presented of recent advances in our knowledge of responses and mechanisms rendering adaptation to saline conditions in sorghum. Different strategies deployed to enhance salinity stress tolerance in sorghum are also pointed out. Salinity stress is a growing problem worldwide. Sorghum is the fifth key crop among cereals. Understanding responses and tolerance strategies in sorghum would be therefore helpful effort for providing biomarkers for designing greatest salinity-tolerant sorghum genotypes. When sorghum exposed to salinity, salinity-tolerant genotypes most probably reprogram their gene expression to activate adaptive biochemical and physiological responses for survival. The review thus discusses the possible physiological and biochemical responses that confer salinity tolerance to sorghum under saline conditions. Although it is not characterized in sorghum, salinity perceiving and transmitting signals to downstream responses via signaling transduction pathways most likely are essential strategy for sorghum adaptation to salinity stress. Sorghum has also shown to withstand moderate saline environments and retain the germination, growth, and photosynthetic activities. Salinity-tolerant sorghum genotypes show the ability to exclude excessive Na from reaching shoots and induce ion homeostasis. Osmotic homeostasis and ROS detoxification are also evident as salinity tolerance strategies in sorghum. These above mechanisms lead to re-establishment of cellular ionic, osmotic, and redox homeostasis as well as photosynthesis efficiency. It is noteworthy that these mechanisms act individually or co-operatively to minimize the salinity hazards and enhance acclimation in sorghum. We conclude, however, that although these responses contribute to sorghum tolerance to salinity stress, they seem to be not adequate at higher concentrations of salinity, which agrees with sorghum ranking as moderately salinity-tolerant crop. Also, some of these tolerance strategies reported in other crops are not well studied and documented in sorghum, but most probably have roles in sorghum. Further improvement in sorghum salinity tolerance using different approaches is definitely necessary to meet the requirements of its harsh production environments, and therefore, these approaches are addressed.
Topics: Edible Grain; Salinity; Salt Stress; Salt Tolerance; Sorghum
PubMed: 34224010
DOI: 10.1007/s00425-021-03671-8 -
British Journal of Sports Medicine Sep 2012The general practice of altitude training is widely accepted as a means to enhance sport performance despite a lack of rigorous scientific studies. For example, the... (Review)
Review
The general practice of altitude training is widely accepted as a means to enhance sport performance despite a lack of rigorous scientific studies. For example, the scientific gold-standard design of a double-blind, placebo-controlled, cross-over trial has never been conducted on altitude training. Given that few studies have utilised appropriate controls, there should be more scepticism concerning the effects of altitude training methodologies. In this brief review we aim to point out weaknesses in theories and methodologies of the various altitude training paradigms and to highlight the few well-designed studies to give athletes, coaches and sports medicine professionals the current scientific state of knowledge on common forms of altitude training. Another aim is to encourage investigators to design well-controlled studies that will enhance our understanding of the mechanisms and potential benefits of altitude training.
Topics: Acclimatization; Altitude; Athletic Performance; Exercise; Forecasting; Hemoglobins; Humans; Hypoxia; Oxygen Consumption; Residence Characteristics; Running
PubMed: 22797528
DOI: 10.1136/bjsports-2012-091231 -
The Science of the Total Environment Oct 2022Global climate change due to anthropogenic activities affects the dynamics of aquatic communities by altering the adaptive capacities of their inhabitants. Analysis of... (Review)
Review
Global climate change due to anthropogenic activities affects the dynamics of aquatic communities by altering the adaptive capacities of their inhabitants. Analysis of blood provides valuable insights in the form of a comprehensive representation of the physiological and functional status of fish under various environmental and treatment conditions. This review synthesizes currently available information about blood biomarkers used in climate change induced stress responses in fish. Alterations in informative blood-based indicators are used to monitor the physiological fitness of individual fishes or entire populations. Specific characteristics of fish blood, such as serum and plasma metabolites, cell composition, cellular abnormalities, cellular and antioxidant enzymes necessitate adapted protocols, as well as careful attention to experimental designs and meticulous interpretation of patterns of data. Moreover, the sampling technique, transportation, type of culture system, acclimation procedure, and water quality must all be considered for valid interpretation of hemato-biochemical parameters. Besides, blood collection, handling, and storage time of blood samples can all have significant impacts on the results of a hematological analysis, so it is optimal to perform hemato-biochemical evaluations immediately after blood collection because long-term storage can alter the results of the analyses, at least in part as a result of storage-related degenerative changes that may occur. However, the scarcity of high-throughput sophisticated approaches makes fish blood examination studies promising for climate-driven stress responses in fish.
Topics: Acclimatization; Animals; Antioxidants; Biomarkers; Climate Change; Fishes
PubMed: 35753474
DOI: 10.1016/j.scitotenv.2022.156910