Thermal Adaptation Research Articles

Hyperthermia-induced changes in leukocyte survival and phagocytosis: a comparative study in bovine and buffalo leukocytes.

Heat stress negatively affects health, welfare, and livestock productivity by impairing immune function, increasing disease incidence. In recent years, there has been increasing interest in understanding the immune system of water buffalo due to the growing economic impact of this species for the high quality and nutritional value of buffalo milk. While there are common responses across bovine and buffalo species, there are also some species-specific variations in the physiological responses to heat stress, mainly attributed to differences in metabolism and heat dissipation efficiency. At cellular level, the exposure to thermal stress induces several anomalies in cell functions. However, there is limited knowledge about the differential response of bovine and buffalo leucocytes to early and late exposure to different degrees of thermal exposure. The aim of this study was to compare the in vitro effect of hyperthermia on apoptosis and phagocytosis in leukocytes from bovine and buffalo species. For this, whole blood samples of six bovines and nine buffaloes were incubated at 39°C (mimicking normothermia condition) or 41°C (mimicking heat stress condition) for 1, 2, and 4 h. Two flow cytometric assays were then performed to evaluate apoptosis and determine functional capacity of phagocytic cells (neutrophils and monocytes). The results showed that the viability of bovine and buffalo leukocytes was differently affected by temperature and time of in vitro exposure. A higher percentage of apoptotic leukocytes was observed in bovines than in buffaloes at 39°C (3.19 vs. 1.51, p < 0.05) and 41°C (4.01 vs. 1.69, p < 0.05) and for all incubation time points (p < 0.05). In contrast, no difference was observed in the fraction of necrotic leukocytes between the two species. In both species, lymphocytes showed the highest sensitivity to hyperthermia, showing an increased apoptosis rates along with increased incubation time. In bovine, apoptotic lymphocytes increased from 5.79 to 12.7% at 39°C (p < 0.05), in buffalo, this population increased from 1.50 to 3.57% at 39°C and from 2.90 to 4.99% at 41°C (p < 0.05). Although no significant differences were found between the two species regarding the percentage of phagocytic neutrophils, lower phagocytosis capacity values (MFI, mean fluorescence intensity) were found in bovines compared with buffaloes at 41°C (27960.72 vs. 53676.45, p > 0.05). However, for monocytes, the differences between species were significant for both phagocytosis activity and capacity with lower percentages of bovine phagocytic monocytes after 2 h at 39°C and after 1 h at 41°C. The bovine monocytes showed lower MFI values for all temperature and time variations than buffaloes (37538.91 vs. 90445.47 at 39°C and 33752.91 vs. 70278.79 at 41°C, p < 0.05). In conclusion, the current study represents the first report on the comparative analysis of the effect of in vitro heat stress on bovine and buffalo leukocyte populations, highlighting that the leukocytes of buffalo exhibit relatively higher thermal adaptation than bovine cells.

A geospatial decision support system to support policy implementation on climate change in EU

AbstractClimate change (CC) is a global problem bringing multiple different changes in different regions that exacerbate the conflict between landscape demands. Policy in EU and elsewhere are facing the huge challenge of CC by developing specific regulations and strategies (e.g., European climate law, RDP 2014–2020) generally shaped in the United Nations Frameworks Convention on Climate Change (UNFCCC). The “new EU strategy on adaptation to climate change” sets out how the EU can adapt to the unavoidable impacts of CC and become climate resilient by 2050. Unfortunately, the factual implementation of these policies remains critical. Most often there is a lack of science‐based decision support tools empowering regional and local levels to act toward climate resilience. Here we have produced a strong interdisciplinary research effort to support the implementation of the EU strategy on adaptation to CC by providing free web‐based Decision Support Systems having a strong focus on factual territories. Our Geospatial Decision Support System aims to support local authorities/communities, scientists, and other stakeholders in EU and more in detail in Italy in better understanding and implementing local adaptation to climate change by means of a “Climate Change Resilience” toolbox oriented to evaluate the climatic anomalies and thermal crop adaptation. Specifically, in this research, two implemented tools have been discussed: (i) tool on General climatic variation and (ii) tool on Crop thermal adaptation. These tools are demonstrated in two different case studies at both EU and national level. Such a toolbox has been produced in the framework of the LANDSUPPORT Horizon 2020 project (www.landsupport.eu).

Personal Comfort System Approach Associated with Fan Usage: A Review

Due to the significant energy consumption of the air conditioner (AC), an alternative energy-saving method is required. To achieve this objective, the design of a building's heating, ventilation, and air conditioning (HVAC) systems must comply to the energy consumption criteria without sacrificing occupant comfort. In this instance, the personal comfort system (PCS) provides a promising means of meeting the demand. This paper aims to summarize the recent discoveries and research on personal comfort systems combined with fan usage. The PCS in conjunction with fan use, which is regarded as the most prevalent thermal adaptation behaviour, offers advantages in terms of conditioning the indoor thermal environment, modulating the person's interaction with the surrounding environmental control system, and reducing the excessive use of energy on HVAC.

Weak correlations among leaf thermal metrics, economic traits and damages under natural heatwaves

The frequency and intensity of heatwaves are increasing around the world, causing severe damages to plants, but whether leaf thermal metrics is in line with leaf economic spectrum is still controversial. Here, we measured leaf damage ratio, leaf thermal metrics (tolerance and sensitivity) and economic traits of 131 woody species across five cities along the Yangtze River after a two-month natural extreme temperature event. We found that leaf thermal sensitivity but not thermal tolerance was correlated with leaf damage ratio, and the relationships between leaf thermal metrics and economic traits were weak, indicating that leaf thermal adaptation may be independent from leaf carbon construction. This study suggests a potential indicator for predicting plant survival under heatwaves, urging future research to explore more physiological traits to comprehensively understand plant heat responses and adaptations.

Stronger compensatory thermal adaptation of soil microbial respiration with higher substrate availability.

Ongoing global warming is expected to augment soil respiration by increasing the microbial activity, driving self-reinforcing feedback to climate change. However, the compensatory thermal adaptation of soil microorganisms and substrate depletion may weaken the effects of rising temperature on soil respiration. To test this hypothesis, we collected soils along a large-scale forest transect in eastern China spanning a natural temperature gradient, and we incubated the soils at different temperatures with or without substrate addition. We combined the exponential thermal response function and a data-driven model to study the interaction effect of thermal adaptation and substrate availability on microbial respiration and compared our results to those from two additional continental and global independent datasets. Modeled results suggested that the effect of thermal adaptation on microbial respiration was greater in areas with higher mean annual temperatures, which is consistent with the compensatory response to warming. In addition, the effect of thermal adaptation on microbial respiration was greater under substrate addition than under substrate depletion, which was also true for the independent datasets reanalyzed using our approach. Our results indicate that thermal adaptation in warmer regions could exert a more pronounced negative impact on microbial respiration when the substrate availability is abundant. These findings improve the body of knowledge on how substrate availability influences the soil microbial community-temperature interactions, which could improve estimates of projected soil carbon losses to the atmosphere through respiration.

Alterations in Histone Methylation States Increased Profusion of Lethal(2)-Essential-for-Life-Like (l(2)elf), Trithorax and Polycomb Genes in Apis mellifera under Heat Stress.

Histone post-translational modifications (PTMs) represent a key mechanism in the thermal adaptation of the honeybee Apis mellifera. In this study, a chromatin immunoprecipitation assay and qPCR were employed to explore the changes in the methylation states of H3K4m2, H3K4m3, H3K27m2 and H3K27m3 associated with l2efl (ID: 72474, 724405, 724488), histone methyltransferases (HMTs) ((trx) and PR-set7) and Polycomb (Pc) and (Su(z)12) genes in A. m. jemenitica (tolerant subspecies) and A. m. carnica (susceptible subspecies) in response to heat treatment (42 °C for 1 h). The results revealed significant enrichment fold changes in the methylation/demethylation of most H3K4 and H3K27 marks at all targeted genes. These changes increased the profusion of l2efl (ID: 72474, 724405, 724488), histone methyltransferases (HMTs) (trx) and Polycomb (Pc) and Su(z)12 and decreased the profusion of HMT (PR-set7) in both honeybee subspecies. The changes in the methylation enrichment folds of histone methyltransferases (HMTs) ((trx), PR-set) and Polycomb (Pc), Su(z)12 genes demonstrate the well-harmonized coordination of epigenetic gene regulation in response to heat treatment. Compared to the control, the changes in the methylation enrichment folds of H3K4m3 at Polycomb Su(z)12 were about 30× and 100× higher in treated A. m. jemenitica and A.m. carnica, respectively. Similarly, changes in the methylation/demethylation enrichment folds of HMT (trx) and Polycomb (Pc) and Su(z)12 were 2-3× higher in A. m. carnica than in A. m. jemenitica after treatment (42 °C). It is evident that post-translational chromatin modification in both honeybee subspecies can diminish heat stress impact by (I) increasing the transcriptional provision of l2efl associated with survival and (II) increasing the silencing of genes associated with general cellular activities.

Evolutionary radiation and microbial community dynamics shape the thermal tolerance of Fungiidae in the southern South China Sea.

Fungiidae have shown increased thermal adaptability in coral reef ecosystems under global warming. This study analyzes the evolutionary divergence and microbial communities of Fungiidae in the Sanjiao Reef of the southern South China Sea and explores the impact of coral evolution radiation and microbial dynamics on the heat tolerance of Fungiidae. The results found that Cycloseris was an ancient branch of Fungiidae, dating back approximately 147.8953 Mya, and Fungiidae differentiated into two ancestral clades (clades I and II) before 107.0312 Ma. Fungiidae exhibited specific symbioses with the Cladocopium C27 sub-clade. Notably, the Cladocopium C1 sub-clade has a high relative abundance in clade I, whereas the heat-tolerant Cladocopium C40 and C3u sub-clades subdominante in clade II. Regarding bacterial communities, Cycloseris costulata, the earliest divergent species, had higher bacterial β-diversity, while the latest divergent species, Lithophyllon scabra, displayed lower bacterial α-diversity and higher community stability. Beneficial bacteria dominante Fungiidae's bacterial community (54%). The co-occurrence network revealed that microbial networks in clade II exhibited lower complexity and greater resilience than those in clade I. Our study highlights that host evolutionary radiation and microbial communities shaped Fungiidae's thermal tolerance. The variability in subdominant Symbiodiniaceae populations may contribute to interspecific differences in thermal tolerance along the evolutionary branches of Fungiidae. The presence of abundant beneficial bacteria may further enhance the thermal ability of the Fungiidae. Furthermore, the later divergent species of Fungiidae have stronger heat tolerance, possibly driven by the increased regulation ability of the host on the bacterial community, greater microbial community stability, and interaction network resistance.IMPORTANCECoral reefs are facing significant threats due to global warming. The heat tolerance of coral holobionts depends on both the coral host and its microbiome. However, the association between coral evolutionary radiation and interspecific differences in microbial communities remains unclear. In this study, we investigated the role of evolutionary radiation and microbial community dynamics in shaping the thermal acclimation potential of Fungiidae in the Sanjiao Reef of the southern South China Sea. The study's results suggest that evolutionary radiation enhances the thermal tolerance of Fungiidae. Fungiidae species that have diverged more recently have exhibited a higher presence of heat-tolerant Symbiodiniaceae taxa, more stable bacterial communities, and a robust and resilient microbial interaction network, improving the thermal adaptability of Fungiidae. In summary, this study provides new insights into the thermal adaptation patterns of corals under global warming conditions.

Impacts of thermophoretic deposition and thermal radiation on heat and mass transfer analysis of ternary nanofluid flow across a wedge

ABSTRACT Ternary nanofluids have attracted significant attention due to their improved thermal characteristics and adaptability for many applications. Nanoparticles interact with one another in complex ways and have a noticeable effect on heat transmission. Due to this, nanofluids have significant promise in several fields. Notably, investigating the behavior of ternary nanofluids via a wedge enables the optimization of heat transfer processes in heat exchangers, cooling mechanisms, and thermal control systems. The current study examines the effects of thermal radiation and thermophoretic particle deposition on the ternary hybrid nanofluid flow across a wedge. The governing equations are precisely modeled and solved numerically using Runge Kutta Fehlberg’s fourth-fifth order (RKF-45) approach and shooting procedure. The governing equations are reduced to ordinary differential equations (ODEs) using similarity transformations. The results are efficiently shown via visual depictions, facilitating a precise understanding of the outcomes. The study outcomes show that increased thermophoretic parameter and solid volume fraction decreases the mass transfer rate. Researchers may incorporate this comprehension to effectively utilize ternary nanofluids to enhance heat transfer in practical situations, as well as the development of technology and energy management.

Lipid-Mediated Mechanisms of Thermal Adaptation and Thermoregulatory Behavior in Animals.

Temperature affects a variety of cellular processes because the molecular motion of cellular constituents and the rate of biochemical reactions are sensitive to temperature changes. Thus, the adaptation to temperature is necessary to maintain cellular functions during temperature fluctuation, particularly in poikilothermic organisms. For a wide range of organisms, cellular lipid molecules play a pivotal role during thermal adaptation. Temperature changes affect the physicochemical properties of lipid molecules, resulting in the alteration of cell membrane-related functions and energy metabolism. Since the chemical structures of lipid molecules determine their physicochemical properties and cellular functions, cellular lipids, particularly fatty acid-containing lipid molecules, are remodeled as a thermal adaptation response to compensate for the effects of temperature change. In this chapter, we first introduce the structure and biosynthetic pathway of fatty acid-containing lipid molecules, such as phospholipid and triacylglycerol, followed by a description of the cellular lipid-mediated mechanisms of thermal adaptation and thermoregulatory behavior in animals.

Winter is not coming: evaluating impacts of changing winter conditions on coregonine reproductive phenology

Fishes in northern latitude lakes are at risk from climate-induced warming because the seasonality in water temperature is degrading, which can change ecosystem properties and the phenology of life-history events. Temperature-dependent embryo development models were developed for a group of cold, stenothermic fishes (Salmonidae Coregoninae) to assess the potential impacts of climate-induced changes in water temperature on cisco (Coregonus artedi) from two populations in Lake Superior (Apostle Islands [USA] and Thunder Bay [Canada]) and one in Lake Ontario (USA), vendace (C. albula) in Lake Southern Konnevesi (Finland), and European whitefish (C. lavaretus) in lakes Southern Konnevesi, Constance (Germany), Geneva (France), and Annecy (France). Water temperatures for each study group were simulated and changes in reproductive phenology across historic (1900–2006) and three future climatic-warming scenarios (2007–2099) were investigated. Models predicted that increases in water temperatures are likely to cause delayed spawning, shorter embryo incubation durations, and earlier larval hatching. Relative changes increased as warming scenarios increased in severity and were higher for littoral as compared to pelagic populations. Our simulations demonstrated that slower cooling in the autumn and (or) more rapid warming in spring can translate into substantial changes in the reproductive phenology of coregonines among our study groups. We expect that the changes in reproductive phenology predicted by our models, in the absence of thermal or behavioral adaptation, will have negative implications for population sustainability.

Comparative Transcriptome Analyses Provide New Insights into the Evolution of Divergent Thermal Resistance in Two Eel Gobies.

Adaptation to thermal conditions in tidal mudflats always involves tolerating frequent fluctuations and often extreme environmental temperatures. Regulation of gene expression plays a fundamental role in the evolution of these thermal adaptations. To identify the key gene regulatory networks associated with the thermal adaptation, we investigated the capability of cold tolerance, as well as the transcriptomic changes under cold stress in two mudflat inhabitants (Odontamblyopus lacepedii and O. rebecca) with contrasting latitude affinity. Our results revealed a remarkable divergent capacity of cold tolerance (CTmin: 0.61 °C vs. 9.57 °C) between the two gobies. Analysis of transcriptomic changes under cold stress unveiled 193 differentially expressed genes exhibiting similar expression profiles across all tissues and species, including several classic metabolic and circadian rhythm molecules such as ACOD and CIART that may represent the core cold response machinery in eel gobies. Meanwhile, some genes show a unique expression spectrum in the more cold-tolerant O. lacepedii suggesting their roles in the enhanced cold tolerance and hence the extreme thermal adaptations. In addition, a weighted gene co-expression network analysis (WGCNA) revealed a subset of metabolic hub genes including MYH11 and LIPT2 showing distinct down-regulation in O. lacepedii when exposed to cold stress which highlights the role of reduced energy consumption in the enhanced cold tolerance of eel gobies. These findings not only provide new insights into how mudflat teleosts could cope with cold stress and their potential evolutionary strategies for adapting to their thermal environment, but also have important implications for sound management and conservation of their fishery resources in a scenario of global climate warming in the marine realm.

Graphene oxide dispersed mesoporous ZIF-8-encapsulated laccase for removal of toluidine blue with multiple enhanced stability.

The extensive use and discharge of toluidine blue have caused serious problems to the water environment. As a green biocatalyst, laccase has the ability to decolorize the dyes, but it is limited by poor reusability and low stability. Metal-organic frameworks (MOFs) are a good platform for enzyme immobilization. However, due to the weak dispersion of MOFs, the enzyme activity is inevitably inhibited. Herein, we proposed to use graphene oxide (GO) as the dispersion medium of mesoporous ZIF-8 to construct MZIF-8/GO bi-carrier for laccase (FL) immobilization. On account of the narrower bandgap energy of FL@MZIF-8/GO (4.07eV) than that of FL@MZIF-8 (4.69eV), electron transport was enhanced which later increased the catalytic activity of the immobilized enzyme. Meanwhile, the improved hydrophilicity characterized by contact angle and full infiltration time further promoted the efficiency of the enzymatic reaction. Benefiting from such regulatory effects of GO, the composite showed excellent storage stability and reusability, as well as multifaceted enhancements including pH, thermal, and solvent adaptation. On the basis of the characterized synergistic effect of adsorption and degradation, FL@MZIF-8/GO was successfully applied to the degradation of toluidine blue (TB) with a removal rate of 94.8%. Even in actual treated wastewater, the highest removal rate still reached more than 80%. Based on the inner mechanism analysis and the universality study, this material is expected to be widely used in the degradation of pollutants in real water under complex environmental conditions.

Influence of outdoor temperature on thermal adaptation: Annual neutral temperature and thermal sensitivity

Building evaluation and guidance for naturally ventilated buildings rely on adaptive comfort models and standards. This study aims to establish an analytical and predictive thermal sensation and adaptation method. The proposed approach is based on the Griffiths method, which reveals a sinusoidal pattern in the neutral temperature and Griffiths coefficient throughout the year. Calculating the daily neutral temperature and evaluating thermal sensitivity through the Griffiths method highlight the delayed response of neutral temperature to outdoor temperature. With the input of operative and outdoor temperature, the Griffiths method predicts adaptive thermal sensation better than the PMV model. The regular fluctuations of neutral temperatures and Griffiths coefficients provide new research ideas and references for designing naturally ventilated buildings. Further research works are still required to check the method’s applicability in the presence of various climate characteristics.

Thermal tolerance in Pacific salmon: A systematic review of species, populations, life stages and methodologies

AbstractAquatic systems are warming and exceeding upper thermal limits (UTLs) for many fish species, yet understanding how they inform resilience to climate change is challenging. Using Pacific salmon (Oncorhynchus spp.) as a model, we conducted a systematic review involving 168 papers investigating UTL in five species. We found considerable variation in UTL among species, within species and across life stages; largely attributed to methodological approaches (e.g. CTmax/UILT, Aerobic/Cardiac Scope, Thermal Migration Barriers, Rearing Mortality, Thermal Preference/Avoidance). Given that each method has strengths and weaknesses owing to logistics, time scale and ecological realism, we offer a new framework for assessing vulnerability to warming that stresses the importance of considering UTL metrics in the context of intended use (i.e. the development of management guidelines, projections of future persistence and survival) and what aspect (physiological or behavioural) of thermal response a metric investigates. Comparing studies with identical UTL approaches revealed that within species, UTL was higher for populations historically encountering higher temperatures—suggesting local thermal adaptation. Within populations, UTL differed across the lifecycle, being highest in fry and lowest in embryo and migrating adults, but this was not universal. For spawning Pacific salmon, UTL has not been assessed and few studies have examined estuarine and marine stages. Ultimately, this data gap limits the life‐history thermal perspectives that can be drawn and may indicate a broader gap for all fishes, given that Pacific salmon are among the most well‐studied species. Our framework illustrates the inherent and methodological inconsistencies in UTL and offers a guide for how thermal limits can best be used to assess the warming tolerance and vulnerability of fishes.

Study on the dynamic effects of plateau hypoxic and cold environment on the thermal adaptation of short-term sojourners in Xizang

The plateau hypoxic environment can affect the thermoregulation process of the human body, and due to the different acclimatization ability to the hypoxic environment, the thermal requirements among the people who enter Xizang at different times may be different. Accordingly, this study aims to clarify how plateau hypoxic environments influence the physiological and subjective responses of people entering Xizang at different times. And field experiments were conducted in Xi'an and Lhasa, respectively, to compare the thermal responses and oxygen responses of the subjects under different temperature conditions on the plain, the first day of entering Xizang and the 15th day of entering Xizang. The results showed that under the hypoxic environment, the thermal sensation of the subjects decreased. With the extension of the time entering Xizang, the influence of the hypoxic environment on thermal comfort was gradually weakened, but under the low temperature environment, the effect of hypoxia on thermal response was not significantly reduced. The results of this study can help to reveal how plateau hypoxic environments affect human thermal comfort and provide a theoretical basis for the design of indoor thermal environment parameters suitable for sojourners entering Xizang at different times.

Chronic exposure to environmental temperature attenuates the thermal sensitivity of salmonids

Metabolism, the biological processing of energy and materials, scales predictably with temperature and body size. Temperature effects on metabolism are normally studied via acute exposures, which overlooks the capacity for organisms to moderate their metabolism following chronic exposure to warming. Here, we conduct respirometry assays in situ and after transplanting salmonid fish among different streams to disentangle the effects of chronic and acute thermal exposure. We find a clear temperature dependence of metabolism for the transplants, but not the in-situ assays, indicating that chronic exposure to warming can attenuate salmonid thermal sensitivity. A bioenergetic model accurately captures the presence of fish in warmer streams when accounting for chronic exposure, whereas it incorrectly predicts their local extinction with warming when incorporating the acute temperature dependence of metabolism. This highlights the need to incorporate the potential for thermal acclimation or adaptation when forecasting the consequences of global warming on ecosystems.

Long-term warming increased carbon sequestration capacity in a humid subtropical forest.

Tropical and subtropical forests play a crucial role in global carbon (C) pools, and their responses to warming can significantly impact C-climate feedback and predictions of future global warming. Despite earth system models projecting reductions in land C storage with warming, the magnitude of this response varies greatly between models, particularly in tropical and subtropical regions. Here, we conducted a field ecosystem-level warming experiment in a subtropical forest in southern China, by translocating mesocosms (ecosystem composed of soils and plants) across 600 m elevation gradients with temperature gradients of 2.1°C (moderate warming), to explore the response of ecosystem C dynamics of the subtropical forest to continuous 6-year warming. Compared with the control, the ecosystem C stock decreased by 3.8% under the first year of 2.1°C warming; but increased by 13.4% by the sixth year of 2.1°C warming. The increased ecosystem C stock by the sixth year of warming was mainly attributed to a combination of sustained increased plant C stock due to the maintenance of a high plant growth rate and unchanged soil C stock. The unchanged soil C stock was driven by compensating and offsetting thermal adaptation of soil microorganisms (unresponsive soil respiration and enzyme activity, and more stable microbial community), increased plant C input, and inhibitory C loss (decreased C leaching and inhibited temperature sensitivity of soil respiration) from soil drying. These results suggest that the humid subtropical forest C pool would not necessarily diminish consistently under future long-term warming. We highlight that differential and asynchronous responses of plant and soil C processes over relatively long-term periods should be considered when predicting the effects of climate warming on ecosystem C dynamics of subtropical forests.

Thermophilic artificial water channels of a lipid-like dendron stabilized by water-containing hydrogen-bonded network

Nature modulates the non-covalent interaction of biomolecules to strengthen their structural integrity against various extreme environments. Water, as the key component in living systems, can provide the H-bonded connectivity to readily stabilize the thermophilic proteins toward thermal adaption. However, this brilliant strategy has seldom been utilized in molecular design since the role of water is less explored in synthetic systems. In this study, we design the lipid-like dendron (LD) to form the hydrated hexagonal columnar (Colh) phase in water-induced self-assembly (WISA). Our findings suggest that the amount of embedded water molecules affects the phase stability of the hydrated Colh phase. The characterization further reveals that remarkable enhancement of phase stability is attributed to the extensive water-containing H-bonded network of the bulk-like core water and interfacial water within the Colh phase. The water-containing H-bonded network prevents artificial water channels (AWCs) in the Colh phase from the destruction of thermal perturbation at temperature higher than the boiling point of water. Moreover, the weakened H-bonded network at high temperatures further accelerates water flow through the AWC of the LD and resulted in the water permeability of an individual AWC (PAWC) of 1.33 × 107 H2O·channel−1·s−1 at 80 °C. This transporting feature in the weak H-bonded network of the bulk AWCs of the LD is similar to the water transport in the hydrophobic channels such as Aquaporin and other single-molecule AWCs. The study suggests that just like how it does to the thermophilic proteins, water can also use its H-bonded network to enhance the thermal stability of synthetic matter and allow them to perform better functions at higher temperatures.

Genetic background and thermal regime influence adaptation to novel environment in the seed beetle, Callosobruchus maculatus.

Climate change is associated with the increase in both the mean and variability of thermal conditions. Therefore, the use of more realistic fluctuating thermal regimes is the most appropriate laboratory method for predicting population responses to thermal heterogeneity. However, the long- and short-term implications of evolving under such conditions are not well understood. Here, we examined differences in key life-history traits among populations of seed beetles (Callosobruchus maculatus) that evolved under either constant control conditions or in an environment with fluctuating daily temperatures. Specifically, individuals from two distinct genetic backgrounds were kept for 19 generations at one of two temperatures, a constant temperature (T = 29 °C) or a fluctuating daily cycle (Tmean = 33 °C, Tmax = 40 °C, and Tmin = 26 °C), and were assayed either in their evolved environment or in the other environment. We found that beetles that evolved in fluctuating environments but were then switched to constant 29 °C conditions had far greater lifetime reproductive success compared with beetles that were kept in their evolved environments. This increase in reproductive success suggests that beetles raised in fluctuating environments may have evolved greater thermal breadth than control condition beetles. In addition, the degree of sexual dimorphism in body size and development varied as a function of genetic background, evolved thermal environment, and current temperature conditions. These results not only highlight the value of incorporating diel fluctuations into climate research but also suggest that populations that experience variability in temperature may be better able to respond to both short- and long-term changes in environmental conditions.

Changing soil available substrate primarily caused by fertilization management contributed more to soil respiration temperature sensitivity than microbial community thermal adaptation

Substrate depletion and microbial community thermal adaptation are major mechanisms that regulate the temperature sensitivity (Q10) of soil microbial respiration. Traditionally, the Q10 of soil microbial respiration is measured using laboratory incubation, which has limits in the continuous input of available substrates and the time scale for microbial community thermal adaptation. How the available substrate and the soil microbial community regulate the Q10 of soil microbial respiration under natural warming conditions remains unclear. To fill this gap in knowledge, a long-term field experiment was conducted consisting of two years of soil respiration observations combined with a soil available substrate and microbial community thermal adaptation analysis under seasonal warming conditions. The Q10 of soil respiration was calculated using the square root method, and it was more affected by the available substrate than by microbial community thermal adaptation. Fertilization management has a stronger effect on soil available substrate than temperature. As the temperature increased, NH4-N proved itself to be important for the bacterial community in the process of Q10 regulation, while dissolved organic carbon and nitrogen were key factors for the fungal community. Based on the niche breadth of microbial community composition, the changing Q10 of the soil respiration was not only closely associated with the specialist community, but also the generalist and neutralist communities. Furthermore, bacterial community thermal adaptation primarily occurred through shifts in the abundances of specialists and neutralists, while changes in species richness and species replacement occurred for the fungal generalists and neutralists. This work indicates that changing available nitrogen and DOC primarily caused by fertilization management contributed more in regulating the Q10 of soil microbial respiration than microbial community thermal adaptation, and there are different mechanisms for bacterial and fungal community thermal adaptation under warming.