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BMJ (Clinical Research Ed.) Jan 2022
Topics: Acclimatization; Cold Temperature; Humans; Hypesthesia; Swimming; Water
PubMed: 34996764
DOI: 10.1136/bmj.o40 -
European Journal of Applied Physiology Feb 2021Over the last few decades, females have significantly increased their participation in athletic competitions and occupations (e.g. military, firefighters) in hot and... (Review)
Review
Over the last few decades, females have significantly increased their participation in athletic competitions and occupations (e.g. military, firefighters) in hot and thermally challenging environments. Heat acclimation, which involves repeated passive or active heat exposures that lead to physiological adaptations, is a tool commonly used to optimize performance in the heat. However, the scientific community's understanding of adaptations to heat acclimation are largely based on male data, complicating the generalizability to female populations. Though limited, current evidence suggests that females may require a greater number of heat acclimation sessions or greater thermal stress to achieve the same magnitude of physiological adaptations as males. The underlying mechanisms explaining the temporal sex differences in the physiological adaptations to heat acclimation are currently unclear. Therefore, the aims of this state-of-the-art review are to: (i) present a brief yet comprehensive synthesis of the current female and sex difference literature, (ii) highlight sex-dependent (e.g. anthropometric, menstrual cycle) and sex-independent factors (e.g. environmental conditions, fitness) influencing the physiological and performance adaptations to heat acclimation, and (iii) address key avenues for future research.
Topics: Acclimatization; Adaptation, Physiological; Animals; Hot Temperature; Humans; Sex Characteristics
PubMed: 33205218
DOI: 10.1007/s00421-020-04550-y -
Plant Physiology and Biochemistry : PPB Nov 2022In the context of climate change, the magnitude and frequency of temperature extremes (low and high temperatures) are increasing worldwide. Changes to the lower extremes... (Review)
Review
In the context of climate change, the magnitude and frequency of temperature extremes (low and high temperatures) are increasing worldwide. Changes to the lower extremes of temperature, known as cold stress (CS), are one of the recurrent stressors in many parts of the world, severely limiting agricultural production. A series of plant reactions to CS could be generalized into morphological, physiological, and biochemical responses based on commonalities among crop plants. However, the differing originality of crops revealed varying degrees of sensitivity to cold and, therefore, exhibited large differences in these responses among the crops. This review discusses the vegetative and reproductive growth effects of CS and highlights the species-specific aspect of each growth stage whereby the reproductive growth CS appears more detrimental in rice and wheat, with marginal yield losses. To mitigate CS negative effects, crop plants have evolved cold-acclimation mechanisms (with differing capability), characterized by specific protein accumulation, membrane modification, regulation of signaling pathways, osmotic regulation, and induction of endogenous hormones. In addition, we reviewed a comprehensive account of management strategies for regulating tolerance mechanisms of crop plants under CS.
Topics: Acclimatization; Cold Temperature; Cold-Shock Response; Crop Production; Hormones
PubMed: 36099808
DOI: 10.1016/j.plaphy.2022.08.024 -
Dermatologie (Heidelberg, Germany) Jan 2023
Topics: Climate Change; Dermatology; Adaptation, Physiological; Acclimatization
PubMed: 36633633
DOI: 10.1007/s00105-022-05087-1 -
Medicine and Science in Sports and... Jul 2021The aim of this study was to compare the effectiveness of exercise versus hot water immersion heat reacclimation (HRA) protocols. (Comparative Study)
Comparative Study
INTRODUCTION
The aim of this study was to compare the effectiveness of exercise versus hot water immersion heat reacclimation (HRA) protocols.
METHODS
Twenty-four participants completed a heat stress test (HST; 33°C, 65% RH), which involved cycling at a power output equivalent to 1.5 W·kg-1 for 35 min whereby thermophysiological variables were measured. This was followed by a graded exercise test until exhaustion. HST1 was before a 10-d controlled hyperthermia (CH) heat acclimation (HA) protocol and HST2 immediately after. Participants completed HST3 after a 28-d decay period without heat exposure and were then separated into three groups to complete a 5-d HRA protocol: a control group (CH-CON, n = 8); a hot water immersion group (CH-HWI, n = 8), and a controlled hyperthermia group (CH-CH, n = 8). This was followed by HST4.
RESULTS
Compared with HST1, time to exhaustion and thermal comfort improved; resting rectal temperature (Tre), end of exercise Tre, and mean skin temperature (Tsk) were lower; and whole body sweat rate (WBSR) was greater in HST2 for all groups (P < 0.05). After a 28-d decay, only WBSR, time to exhaustion, and mean Tsk returned to pre-HA values. Of these decayed variables, only WBSR was reinstated after HRA; the improvement was observed in both the CH-CH and the CH-HWI groups (P < 0.05).
CONCLUSION
The data suggest that HRA protocol may not be necessary for cardiovascular and thermal adaptations within a 28-d decay period, as long as a 10-d CH-HA protocol has successfully induced these physiological adaptations. For sweat adaptations, a 5-d CH or HWI-HRA protocol can reinstate the lost adaptations.
Topics: Acclimatization; Adaptation, Physiological; Adult; Exercise; Female; Hot Temperature; Humans; Immersion; Male; Middle Aged; Water
PubMed: 34127636
DOI: 10.1249/MSS.0000000000002612 -
Global Change Biology Jan 2020Although cross generation (CGP) and multigenerational (MGP) plasticity have been identified as mechanisms of acclimation to global change, the weight of evidence... (Review)
Review
Although cross generation (CGP) and multigenerational (MGP) plasticity have been identified as mechanisms of acclimation to global change, the weight of evidence indicates that parental conditioning over generations is not a panacea to rescue stress sensitivity in offspring. For many species, there were no benefits of parental conditioning. Even when improved performance was observed, this waned over time within a generation or across generations and fitness declined. CGP and MGP studies identified resilient species with stress tolerant genotypes in wild populations and selected family lines. Several bivalves possess favourable stress tolerance and phenotypically plastic traits potentially associated with genetic adaptation to life in habitats where they routinely experience temperature and/or acidification stress. These traits will be important to help 'climate proof' shellfish ventures. Species that are naturally stress tolerant and those that naturally experience a broad range of environmental conditions are good candidates to provide insights into the physiological and molecular mechanisms involved in CGP and MGP. It is challenging to conduct ecologically relevant global change experiments over the long times commensurate with the pace of changing climate. As a result, many studies present stressors in a shock-type exposure at rates much faster than projected scenarios. With more gradual stressor introduction over longer experimental durations and in context with conditions species are currently acclimatized and/or adapted to, the outcomes for sensitive species might differ. We highlight the importance to understand primordial germ cell development and the timing of gametogenesis with respect to stressor exposure. Although multigenerational exposure to global change stressors currently appears limited as a universal tool to rescue species in the face of changing climate, natural proxies of future conditions (upwelling zones, CO vents, naturally warm habitats) show that phenotypic adjustment and/or beneficial genetic selection is possible for some species, indicating complex plasticity-adaptation interactions.
Topics: Acclimatization; Animals; Aquatic Organisms; Climate Change; Ecosystem; Invertebrates
PubMed: 31670444
DOI: 10.1111/gcb.14882 -
British Journal of Sports Medicine Aug 2020
Topics: Acclimatization; Anniversaries and Special Events; Athletic Performance; Competitive Behavior; Hot Temperature; Humans; Sports; Time Factors; Tokyo
PubMed: 32276924
DOI: 10.1136/bjsports-2020-102299 -
International Journal of Molecular... Feb 2022Improvement of crop climate resilience will require an understanding of whole-plant adaptation to specific local environments. This review places features of plant form... (Review)
Review
Improvement of crop climate resilience will require an understanding of whole-plant adaptation to specific local environments. This review places features of plant form and function related to photosynthetic productivity, as well as associated gene-expression patterns, into the context of the adaptation of ecotypes to local environments with different climates in Sweden and Italy. The growth of plants under common cool conditions resulted in a proportionally greater emphasis on the maintenance of photosynthetic activity in the Swedish ecotype. This is compared to a greater emphasis on downregulation of light-harvesting antenna size and upregulation of a host of antioxidant enzymes in the Italian ecotype under these conditions. This differential response is discussed in the context of the climatic patterns of the ecotypes' native habitats with substantial opportunity for photosynthetic productivity under mild temperatures in Italy but not in Sweden. The Swedish ecotype's response is likened to pushing forward at full speed with productivity under low temperature versus the Italian ecotype's response of staying safe from harm (maintaining redox homeostasis) while letting productivity decline when temperatures are transiently cold. It is concluded that either strategy can offer directions for the development of climate-resilient crops for specific locations of cultivation.
Topics: Acclimatization; Arabidopsis; Cold Temperature; Ecotype; Photosynthesis
PubMed: 35216246
DOI: 10.3390/ijms23042129 -
Annals of the New York Academy of... Sep 2020Convergent evolution, where independent lineages evolve similar phenotypes in response to similar challenges, can provide valuable insight into how selection operates... (Review)
Review
Convergent evolution, where independent lineages evolve similar phenotypes in response to similar challenges, can provide valuable insight into how selection operates and the limitations it encounters. However, it has only recently become possible to explore how convergent evolution is reflected at the genomic level. The overlapping outlier approach (OOA), where genome scans of multiple independent lineages are used to find outliers that overlap and therefore identify convergently evolving loci, is becoming popular. Here, we present a quantitative analysis of 34 studies that used this approach across many sampling designs, taxa, and sampling intensities. We found that OOA studies with increased biological sampling power within replicates have increased likelihood of finding overlapping, "convergent" signals of adaptation between them. When identifying convergent loci as overlapping outliers, it is tempting to assume that any false-positive outliers derived from individual scans will fail to overlap across replicates, but this cannot be guaranteed. We highlight how population demographics and genomic context can contribute toward both true convergence and false positives in OOA studies. We finish with an exploration of emerging methods that couple genome scans with phenotype and environmental measures, leveraging added information from genome data to more directly test hypotheses of the likelihood of convergent evolution.
Topics: Acclimatization; Adaptation, Physiological; Animals; Animals, Wild; Biological Evolution; Evolution, Molecular; Genome; Genomics
PubMed: 31241191
DOI: 10.1111/nyas.14177 -
Insect Science Dec 2022In nature, insects concurrently face multiple environmental stressors, a scenario likely increasing with climate change. Integrated stress resistance (ISR) thus often...
In nature, insects concurrently face multiple environmental stressors, a scenario likely increasing with climate change. Integrated stress resistance (ISR) thus often improves fitness and could drive invasiveness, but how physiological mechanisms influence invasion has lacked examination. Here, we investigated cross-tolerance to abiotic stress factors which may influence range limits in the South American tomato pinworm-a global invader that is an ecologically and socially damaging crop pest. Specifically, we tested the effects of prior rapid cold- and heat-hardening (RCH and RHH), fasting, and desiccation on cold and heat tolerance traits, as well as starvation and desiccation survivability between T. absoluta life stages. Acclimation effects on critical thermal minima (CT ) and maxima (CT ) were inconsistent, showing significantly deleterious effects of RCH on adult CT and CT and, conversely, beneficial acclimation effects of RCH on larval CT . While no beneficial effects of desiccation acclimation were recorded for desiccation tolerance, fasted individuals had significantly higher survival in adults, whereas fasting negatively affected larval tolerances. Furthermore, fasted and desiccation acclimated adults had significantly higher starvation tolerance, showing strong evidence for cross-tolerance. Our results show context-dependent ISR traits that may promote T. absoluta fitness and competitiveness. Given the frequent overlapping occurrence of these divergent stressors, ISR reported here may thus partly elucidate the observed rapid global spread of T. absoluta into more stressful environments than expected. This information is vital in determining the underpinnings of multistressor responses, which are fundamental in forecasting species responses to changing environments and management responses.
Topics: Animals; Introduced Species; Acclimatization; Thermotolerance; Larva; Stress, Physiological; Starvation
PubMed: 35290720
DOI: 10.1111/1744-7917.13035