Thermal Response Curves Research Articles

Investigation on in-situ thermal behavior of tunnel surrounding rock based on the thermal probe test

Heat-transfer mechanism of energy tunnel is different from that of conventional borehole heat exchanger, where the thermal flux flows along perpendicular to the tunnel circumferential direction. However, the existing measurement methods cannot directly detect the in-situ thermal behavior and thermal conductivity of surrounding rock of tunnel circumferential direction. Hence, a thermal probe test (TPT) equipment was developed and the TPT was performed to investigate the in-situ thermal behavior of surrounding rock, the thermal conductivity measurement methods of tunnel surrounding rock was proposed and compared with laboratory measurement methods. The results showed that the developed TPT equipment achieved to directly detect the in-situ thermal behavior and thermal conductivity of circumferential surrounding rock. There was a significant variation in thermal response curves of different test areas due to the fact that joint development affected the transfer paths of the thermal flux, the temperature difference between test point 1 and test point 2 could reach up to 11.4 °C. The thermal conductivity tested by TPT was reliable and reflected the in-situ thermal behavior, the deviation was 6.99 % and 1.08 %, respectively, compared with laboratory measurement results. The joint development of the surrounding rock had a major impact on the thermal conductivity, where the thermal conductivity ranged from 0.66 to 2.91 W/m K in the 1# borehole and 1.96 to 3.66 W/m K in the 2# borehole. The local thermal conductivities were difficult to apply to an energy tunnel design, hence, the comprehensive thermal conductivity model of surrounding rock with joints was proposed based on series–parallel theory and was simplified according to the heat-transfer mechanism of energy tunnel. The comprehensive thermal conductivity model provided a new idea for obtaining the heterogeneity of thermal-physical properties of tunnel surrounding rock, which improved performance predictions and optimized design strategies for energy tunnel projects, enhancing their efficiency and reliability in various applications.

Searching for thermal shutdown separators in lithium-ion batteries: Paradigm and practice

This paper focuses on the thermal shutdown separators for thermal runaway control in lithium-ion batteries (LIB). In electrical cars (EV), thermal runaway is the most catastrophic and life-threatening failure mode. Here we reexamined 17 reported phase-change-based thermal shutdown separators and suggested a new design paradigm for thermal shutdown separators of EV level batteries. Through accelerating rate calorimeter (ARC), we have obtained the thermal response curves of three typical EV level batteries: LFP 18,650 battery, NCM 18,650 battery and NCM pouch battery and summarized their critical temperatures. Taking NCM pouch battery as an example, we formed a searching zone for the 17 phase-change-based thermal shutdown separators and found that only 7 of them falling into the promising zone. After analysis on these 7 composite materials, we designed a new trial composite material PBS/PI, which turned out successful in all the following thermal and electrochemical tests. Moreover, we are aware from the beginning that all the reported materials are only tested in button batteries and may not as well apply to EV level batteries. Our own practice has also shown this discrepancy. Thereby we employed thermal simulation to help mapping the discrepancy between the button battery and pouch battery. The results shows that the thermal shutdown happens much earlier in the button battery when elevating the temperature, which tricks researchers into misjudging the material feasibility. This work offers avenues for the searching of thermal shutdown separators in EV level batteries.

Thermal performance of ecosystems: Modeling how physiological responses to temperature scale up in communities

Understanding how ecosystems respond to their environmental temperature is a major challenge. Thermodynamic constraints on species’ metabolic rates are expected to affect ecosystem characteristics, but species interactions and interspecific variation in physiological thermal response curves (TRC) may obscure ecosystem-level responses to temperature. As a result, macroecological patterns related to temperature are still poorly understood.We investigate how physiological TRC scale up to ecosystem-level thermal responses by modifying the Tangled Nature (TaNa) model, a stochastic network model of ecology and evolution. We include new parameterizations that make reproduction, death, and mutation temperature-dependent. We find that ecosystem survival probability depends on how the minimum fitness required for species survival varies with temperature. The thermal response of ecosystem survival probability is the only ecosystem property that is sensitive to interspecific variation in TRC. Species richness scales up directly from the TRC of mutation rate, and average species population sizes are inversely related to mutation rate, with Species Abundance Distributions (SADs) exhibiting more rare species in warmer temperatures. Interactions between species are also inversely related to mutation, with positive interactions occurring more frequently in colder temperatures. The abundance of surviving ecosystems is not sensitive to temperature. This work helps clarify the specific relationships between physiological responses to temperature and ecosystem-level repercussions when species are interacting and adapting to their thermal environments.

Short-term temperature fluctuations increase disease in a Daphnia-parasite infectious disease system.

Climate change has profound effects on infectious disease dynamics, yet the impacts of increased short-term temperature fluctuations on disease spread remain poorly understood. We empirically tested the theoretical prediction that short-term thermal fluctuations suppress endemic infection prevalence at the pathogen's thermal optimum. This prediction follows from a mechanistic disease transmission model analyzed using stochastic simulations of the model parameterized with thermal performance curves (TPCs) from metabolic scaling theory and using nonlinear averaging, which predicts ecological outcomes consistent with Jensen's inequality (i.e., reduced performance around concave-down portions of a thermal response curve). Experimental observations of replicated epidemics of the microparasite Ordospora colligata in Daphnia magna populations indicate that temperature variability had the opposite effect of our theoretical predictions and instead increase endemic infection prevalence. This positive effect of temperature variability is qualitatively consistent with a published hypothesis that parasites may acclimate more rapidly to fluctuating temperatures than their hosts; however, incorporating hypothetical effects of delayed host acclimation into the mechanistic transmission model did not fully account for the observed pattern. The experimental data indicate that shifts in the distribution of infection burden underlie the positive effect of temperature fluctuations on endemic prevalence. The increase in disease risk associated with climate fluctuations may therefore result from disease processes interacting across scales, particularly within-host dynamics, that are not captured by combining standard transmission models with metabolic scaling theory.

Nano additives-enhanced PEG /AlN composites with high cycle stability to improve thermal and heat storage properties

The low thermal conductivity and easy leakage of phase change materials are the shortcomings that hinder their further application for thermal energy storage. It is crucial how to properly match skeleton materials and phases to improve heat transfer in order to solve the above problem. Here, we systematically investigate the effects of nano additives on the phase change and thermal properties of bionic hierarchical porous aluminum nitride-polyethylene glycol (PEG/AlN) composites. Alumina (Al2O3) nanoparticles were found to have the largest enhancement effect for the thermal conductivity of PEG (84% for 4 wt% addition) compared to silica, titanium dioxide, and boron nitride. For these additives, the thermal conductivity and stability of the nano additives-enhanced PEG increase with the increase of their mass fraction. After 100 heating/cooling cycles, the thermal response curve shows that the Al2O3-enhanced PEG can maintain the phase transition behavior, and the measured phase transition temperature agrees well with the differential scanning calorimeter results. The thermal conductivity of the PEG/AlN enhanced with 4 wt% Al2O3 is 20.41 W/m·K, and the melting point and phase change enthalpy are 55.93 °C and 81.05 J/g. In addition to the great improvement in thermal response, the heat storage rate also increases by 36.10%.

Predicting climate change impacts on poikilotherms using physiologically guided species abundance models

Poikilothermic animals comprise most species on Earth and are especially sensitive to changes in environmental temperatures. Species conservation in a changing climate relies upon predictions of species responses to future conditions, yet predicting species responses to climate change when temperatures exceed the bounds of observed data is fraught with challenges. We present a physiologically guided abundance (PGA) model that combines observations of species abundance and environmental conditions with laboratory-derived data on the physiological response of poikilotherms to temperature to predict species geographical distributions and abundance in response to climate change. The model incorporates uncertainty in laboratory-derived thermal response curves and provides estimates of thermal habitat suitability and extinction probability based on site-specific conditions. We show that temperature-driven changes in distributions, local extinction, and abundance of cold, cool, and warm-adapted species vary substantially when physiological information is incorporated. Notably, cold-adapted species were predicted by the PGA model to be extirpated in 61% of locations that they currently inhabit, while extirpation was never predicted by a correlative niche model. Failure to account for species-specific physiological constraints could lead to unrealistic predictions under a warming climate, including underestimates of local extirpation for cold-adapted species near the edges of their climate niche space and overoptimistic predictions of warm-adapted species.

Global maps of lake surface water temperatures reveal pitfalls of air‐for‐water substitutions in ecological prediction

In modeling species distributions and population dynamics, spatially‐interpolated climatic data are often used as proxies for real, on‐the‐ground measurements. For shallow freshwater systems, this practice may be problematic as interpolations used for surface waters are generated from terrestrial sensor networks measuring air temperatures. Using these may therefore bias statistical estimates of species' environmental tolerances or population projections – particularly among pleustonic and epilimnetic organisms. Using a global database of millions of daily satellite‐derived lake surface water temperatures (LSWT), I trained machine learning models to correct for the correspondence between air and LSWT as a function of atmospheric and topographic predictors, resulting in the creation of monthly high‐resolution global maps of air‐LSWT offsets, corresponding uncertainty measures and derived LSWT‐based bioclimatic layers for use by the scientific community. I then compared the performance of these LSWT layers and air temperature‐based layers in population dynamic and ecological niche models (ENM). While generally high, the correspondence between air temperature and LSWT was quite variable and often nonlinear depending on the spatial context. These LSWT predictions were better able to capture the modeled population dynamics and geographic distributions of two common aquatic plant species. Further, ENM models trained with LSWT predictors more accurately captured lab‐measured thermal response curves. I conclude that these predicted LSWT temperatures perform better than raw air temperatures when used for population projections and environmental niche modeling, and should be used by practitioners to derive more biologically‐meaningful results. These global LSWT predictions and corresponding error estimates and bioclimatic layers have been made freely available to all researchers in a permanent archive.

A novel expert-driven methodology to develop thermal response curves and project habitat thermal suitability for cetaceans under a changing climate

Over the last decades, global warming has contributed to changes in marine species composition, abundance and distribution, in response to changes in oceanographic conditions such as temperature, acidification, and deoxygenation. Experimentally derived thermal limits, which are known to be related to observed latitudinal ranges, have been used to assess variations in species distribution patterns. However, such experiments cannot be undertaken on free-swimming large marine predators with wide-range distribution, like cetaceans. An alternative approach is to elicit expert's knowledge to derive species' thermal suitability and assess their thermal responses, something that has never been tested in these taxa. We developed and applied a methodology based on expert-derived thermal suitability curves and projected future responses for several species under different climate scenarios. We tested this approach with ten cetacean species currently present in the biogeographic area of Macaronesia (North Atlantic) under Representative Concentration Pathways 2.6, 4.5 and 8.5, until 2050. Overall, increases in annual thermal suitability were found for Balaenoptera edeni, Globicephala macrorhynchus, Mesoplodon densirostris, Physeter macrocephalus, Stenella frontalis, Tursiops truncatus and Ziphius cavirostris. Conversely, our results indicated a decline in thermal suitability for B. physalus, Delphinus delphis, and Grampus griseus. Our study reveals potential responses in cetaceans' thermal suitability, and potentially in other highly mobile and large predators, and it tests this method's applicability, which is a novel application for this purpose and group of species. It aims to be a cost-efficient tool to support conservation managers and practitioners.

Characterisation and evaluation of paint-coated marine corrosion in carbon steel using eddy current pulsed thermography

Marine atmospheric corrosion is a major challenge for carbon steel. Eddy current pulsed thermography (ECPT) can characterise defects under coating, but it is necessary to consider samples' surface geometry. This paper proposes a statistical approach for paint-coated S275 steel corrosion evaluation based on ECPT. The thermal response curve skewness of each point is utilised to reveal the corrosion region. The normalised skewness avoids the influence of emissivity anisotropy and surface geometry; corrosion can be evaluated by taking excitation coil skewness as a reference. In the results, the differential skewness drops monotonously with corrosion aggravation in 6 months, decreasing more than 90% from the uncorroded zone to the 3-month corrosion sample. The approach provides high sensitivity and detectability in paint-coated corrosion evaluation.

Oil palm expansion increases the vectorial capacity of dengue vectors in Malaysian Borneo.

Changes in land-use and the associated shifts in environmental conditions can have large effects on the transmission and emergence of mosquito-borne disease. Mosquito-borne disease are particularly sensitive to these changes because mosquito growth, reproduction, survival and susceptibility to infection are all thermally sensitive traits, and land use change dramatically alters local microclimate. Predicting disease transmission under environmental change is increasingly critical for targeting mosquito-borne disease control and for identifying hotspots of disease emergence. Mechanistic models offer a powerful tool for improving these predictions. However, these approaches are limited by the quality and scale of temperature data and the thermal response curves that underlie predictions. Here, we used fine-scale temperature monitoring and a combination of empirical, laboratory and temperature-dependent estimates to estimate the vectorial capacity of Aedes albopictus mosquitoes across a tropical forest-oil palm plantation conversion gradient in Malaysian Borneo. We found that fine-scale differences in temperature between logged forest and oil palm plantation sites were not sufficient to produce differences in temperature-dependent demographic trait estimates using published thermal performance curves. However, when measured under field conditions a key parameter, adult abundance, differed significantly between land-use types, resulting in estimates of vectorial capacity that were 1.5 times higher in plantations than in forests. The prediction that oil palm plantations would support mosquito populations with higher vectorial capacity was robust to uncertainties in our adult survival estimates. These results provide a mechanistic basis for understanding the effects of forest conversion to agriculture on mosquito-borne disease risk, and a framework for interpreting emergent relationships between land-use and disease transmission. As the burden of Ae. albopictus-vectored diseases, such as dengue virus, increases globally and rising demand for palm oil products drives continued expansion of plantations, these findings have important implications for conservation, land management and public health policy at the global scale.

Preparation and thermal performance of a novel alloy microencapsulated phase change material (MEPCM)/ceramic composite

Phase change material (PCM)/ceramic composite is qualified to be a novel composite thermal energy storage (TES) material, which can simultaneously utilize the latent heat of phase change materials and sensible heat of ceramic matrix materials to accomplish the storage and release of thermal energy. It exhibits a wide application prospect in the field of medium and high temperature thermal energy storage. However, based on the ceramic porous adsorption PCM, there is still the risk of leakage after the PCM melts in the thermal energy storage stage. In this paper, SnBi58 alloy microencapsulated phase change material (MEPCM) with high thermal reliability was prepared by “double-layer coating, sacrificing inner layer” method, which a thermal expansion void was constructed to accommodate volume expansion of PCM. On this basis, SnBi58 alloy MEPCM/ceramic composite was prepared by the cold-pressing sintering method and its thermal performance was studied. The experimental results show that SnBi58 alloy MEPCM/ceramic composite does not leak at the MEPCM/Matrix mass ratio of 2.5:1, but SnBi58 alloy/ceramic composite leaks at the SnBi58 alloy/Matrix mass ratio of 1.5:1, indicating that SnBi58 alloy MEPCM has good thermal reliability and leak resistance. In addition, compared with the ceramic matrix material, the latent heat of MEPCM/ceramic composite with a mass ratio of 2.5:1 is increased by 30.24 J/g and the thermal conductivity reaches 2.853 W/(m·K), which is 3.67 times of the matrix material. Furthermore, thermal performances of four MEPCM/ceramic composite with different proportions were tested and compared, including thermal conductivity, thermal response curve and infrared thermal imaging. The results show that the higher the proportion of MEPCM, the better the thermal performance of the MEPCM/ceramic composite. Moreover, to predict the thermal conductivity of the novel composites, six thermal conductivity models were compared based on the experimental results, and the results show that the prediction error of Maxwell-Eucken is the smallest which can be used to predict the thermal conductivity of MEPCM/ceramic composite. Finally, the thermal reliability of the composite was tested. The results of DSC and XRD showed that the thermal properties and chemical structure basically have no change before and after thermal cycling. MEPCM/ceramic composite has excellent thermal reliability.

Light-driven mechanism of a photothermal conversion infrared image generation chip

An infrared image generation chip (IR-IGC) based on the photothermal conversion effect was developed. It can transform visible light images into infrared (IR) images. However, full 256 IR grayscales of an 8-bit IR grayscale image cannot always be completely captured due to the short integral time of the IR imaging devices. In this paper, we propose a novel light-driven mechanism of the IR-IGC to break the limitation on the integral time of IR imaging devices. A digital micro-mirror device (DMD) working in its binary mode was adopted for generating a light-driven image sequence including 8 binary images. The IR-IGC was driven by these 8 binary images in turns circularly during a heating period. The heating period was divided into a rising period and a holding period. The temperature of the IR-IGC gradually rised during the rising period and then stabilized during the holding period. After the heating period, the IR-IGC entered a cooling period to dissipate heat and got ready for generating the next frame of IR image. The IR imaging device can capture full 256 grayscales by integrating the IR radiation during the holding period of the IR-IGC. The thermal response curves of the IR-IGC under different light-driven waveforms were simulated. The heating period was set to 20 ms. For the grayscale of 255, the rising period was about 5.89 ms, the holding period was about 13.84 ms, and the cooling period was about 8.32 ms. The maximum temperature rise corresponding to the grayscale of 255 was about 123.71 K. The temperature change caused by unit grayscale was 0.36–0.61 K. We also experimentally tested the performance of the IR-IGC under the light-driven mechanism. Clear IR images with 256 grayscales were captured. And the measured thermal response curve of the IR-IGC conformed to the simulation curve. The light-driven mechanism proposed in this paper can also be extended to generate IR images with a grayscale greater than 8-bit, such as 12-bit and 16-bit.

Trophic state alters the mechanism whereby energetic coupling between photosynthesis and respiration occurs in Euglena gracilis.

Summary The coupling between mitochondrial respiration and photosynthesis plays an important role in the energetic physiology of green plants and some secondary‐red photosynthetic eukaryotes (diatoms), allowing an efficient CO2 assimilation and optimal growth.Using the flagellate Euglena gracilis, we first tested if photosynthesis–respiration coupling occurs in this species harbouring secondary green plastids (i.e. originated from an endosymbiosis between a green alga and a phagotrophic euglenozoan). Second, we tested how the trophic state (mixotrophy and photoautotrophy) of the cell alters the mechanisms involved in the photosynthesis–respiration coupling.Energetic coupling between photosynthesis and respiration was determined by testing the effect of respiratory inhibitors on photosynthesis, and measuring the simultaneous variation of photosynthesis and respiration rates as a function of temperature (i.e. thermal response curves). The mechanism involved in the photosynthesis–respiration coupling was assessed by combining proteomics, biophysical and cytological analyses.Our work shows that there is photosynthesis–respiration coupling and membrane contacts between mitochondria and chloroplasts in E. gracilis. However, whereas in mixotrophy adjustment of the chloroplast ATP/NADPH ratio drives the interaction, in photoautotrophy the coupling is conditioned by CO2 limitation and photorespiration. This indicates that maintenance of photosynthesis–respiration coupling, through plastic metabolic responses, is key to E. gracilis functioning under changing environmental conditions.

Surviving winter: Physiological regulation of energy balance in a temperate ectotherm entering and exiting brumation

Characterizing the physiological response to prolonged cold exposure is essential for understanding the maintenance of long-term energy balance. As part of their natural life cycle, temperate ectotherms are often exposed to seasonal variation in temperatures, including extended periods of cold well below their activity range. Relatively little is known about variation in physiological responses as vertebrate ectotherms enter and exit brumation in response to sustained cold temperatures. We tested the influence of temperature on physiology before, during, and after a simulated brumation in the checkered garter snake (Thamnophis marcianus), a widespread ectothermic vertebrate. We tested for the relative effect of immediate temperature and physiological context (entering or exiting brumation) on hormones regulating energy balance, indicators of energy availability, and resting metabolic rate (V̇O2). Plasma corticosterone, glucose, and insulin, as well as immune cell heterophil: lymphocyte ratios responded to temperature, though they did so with different thermal response curves. Thermal sensitivity varied both among and within physiological measures depending on whether animals were going into or coming out of brumation. Additionally, V̇O2 was regulated beyond simple temperature-dependence, whereby post-brumation measures were depressed relative to pre-brumation measures at the same temperature. This pattern was characterized by a change in the temperature coefficient (Q10), with a larger pre-brumation Q10, suggesting reduced thermal sensitivity of metabolic rate following a period of extended cold exposure. The integrated physiological response presented here demonstrates not only temperature dependence across physiological axes, but seasonal variation in thermal responsiveness. Our results suggest that energy allocation decisions and hormonal regulation of underlying processes promote differing levels of thermal sensitivity when entering or exiting brumation.

Continental vs. Global Niche-Based Modelling of Freshwater Species’ Distributions: How Big Are the Differences in the Estimated Climate Change Effects?

Thermal response curves that depict the probability of occurrence along a thermal gradient are used to derive various species’ thermal properties and abilities to cope with warming. However, different thermal responses can be expected for different portions of a species range. We focus on differences in thermal response curves (TRCs) and thermal niche requirements for four freshwater fishes (Coregonus sardinella, Pungitius pungitius, Rutilus rutilus, Salvelinus alpinus) native to Europe at (1) the global and (2) European continental scale. European ranges captured only a portion of the global thermal range with major differences in the minimum (Tmin), maximum (Tmax) and average temperature (Tav) of the respective distributions. Further investigations of the model-derived preferred temperature (Tpref), warming tolerance (WT = Tmax − Tpref), safety margin (SM = Tpref − Tav) and the future climatic impact showed substantially differing results. All considered thermal properties either were under- or overestimated at the European level. Our results highlight that, although continental analyses have an impressive spatial extent, they might deliver misleading estimates of species thermal niches and future climate change impacts, if they do not cover the full species ranges. Studies and management actions should therefore favor whole global range distribution data for analyzing species responses to environmental gradients.

Effect of temperature on the unimodal size scaling of phytoplankton growth

Contrary to predictions by the allometric theory, there is evidence that phytoplankton growth rates peak at intermediate cell sizes. However, it is still unknown if this pattern may result from the effect of experimental temperature. Here we test whether temperature affects the unimodal size scaling pattern of phytoplankton growth by (1) growing Synechococcus sp., Ostreococcus tauri, Micromonas commoda and Pavlova lutheri at 18 °C and 25 °C, and (2) using thermal response curves available in the literature to estimate the growth rate at 25 °C as well as the maximum growth rate at optimal temperature for 22 species assayed previously at 18 °C. We also assess the sensitivity of growth rate estimates to the metric employed for measuring standing stocks, by calculating growth rates based on in vivo fluorescence, chlorophyll a concentration, cell abundance and biomass (particulate organic carbon and nitrogen content). Our results show that the unimodal size scaling pattern of phytoplankton growth, with a peak at intermediate cell sizes, is observed at 18 °C, 25 °C and at the optimal temperature for growth, and that it prevails irrespective of the standing-stock metric used. The unimodal size scaling pattern of phytoplankton growth is supported by two independent field observations reported in the literature: (i) a positive relationship between cell size and metabolic rate in the picophytoplankton size range and (ii) the dominance of intermediate-size cells in nutrient-rich waters during blooms.

A Method for Thermal Resistance Test of Reverse-Conducting IGBT (RC-IGBT)

The RC-IGBT is integrated IGBT and fast recovery diode (FRD) on the same chip. RC-IGBT has smaller size, higher power density, lower cost, and higher reliability. However, due to the snap-back effect, the traditional test circuit and method cannot accurately measure the thermal resistance of RC-IGBT. In this paper, a thermal resistance test circuit based on series compensation of two devices is proposed, and the voltage drop Vec of the body diode is taken as the temperature sensitive parameter of RC-IGBT. The thermal response curve is obtained basing on the change of Vec with temperature. By comparing the traditional method with the new method, it can be seen that the new method can greatly improve the test accuracy.

Responses of spawning thermal suitability to climate change and hydropower operation for typical fishes below the Three Gorges Dam

River thermal regime is a critical factor affecting the initiation of spawning and breeding success in freshwater fish species. The four main domestic carps (FMDCs) and Chinese sturgeon are representative warm-water and cool-water fishes with different spawning thermal requirements in the Yangtze River Basin, China. This study focused on these two types of fish species below the Three Gorges Dam (TGD), and thermal response curves of fish spawning were constructed. The daily thermal suitability index (TSI) was simulated based on scenario analysis of climate-induced water warming and cooling. The variation in four TSI-based spawning indicators was then analyzed to evaluate the response of fish spawning to climate change and hydropower operation. The results showed that the spawning time is likely to be advanced by 1.3 days on average for the FMDCs and delayed by 2.1 days on average for the Chinese sturgeon with a 0.2 °C increase in the water temperature. For the FMDCs, climate warming would narrow the spawning window, although it may advance the spawning time that has been postponded by TGD operation, and climate cooling would widen the spawning window but further postpone spawning. For the Chinese sturgeon, climate warming would aggravate the negative impacts of TGD operation by further narrowing the spawning window and delaying spawning, while climate cooling would likely offset the negative impacts of TGD operation on fish spawning. We suggest that adjusting hydropower operation rules, e.g., elevating the water temperature in the early spawning period of the FMDCs to expand the spawning window and reducing the water temperature by at least 1.2 °C during the spawning period of the Chinese sturgeon, is essential for maintaining and restoring the natural spawning process and populations. Our study is also beneficial for inferring the cumulative impacts of cascading hydropower operations and provides insights for the management and conservation of fish species with different thermal tolerances in other hotspot regions.

Incorporating hydrology into climate suitability models changes projections of malaria transmission in Africa

Continental-scale models of malaria climate suitability typically couple well-established temperature-response models with basic estimates of vector habitat availability using rainfall as a proxy. Here we show that across continental Africa, the estimated geographic range of climatic suitability for malaria transmission is more sensitive to the precipitation threshold than the thermal response curve applied. To address this problem we use downscaled daily climate predictions from seven GCMs to run a continental-scale hydrological model for a process-based representation of mosquito breeding habitat availability. A more complex pattern of malaria suitability emerges as water is routed through drainage networks and river corridors serve as year-round transmission foci. The estimated hydro-climatically suitable area for stable malaria transmission is smaller than previous models suggest and shows only a very small increase in state-of-the-art future climate scenarios. However, bigger geographical shifts are observed than with most rainfall threshold models and the pattern of that shift is very different when using a hydrological model to estimate surface water availability for vector breeding.

Different levels of energetic coupling between photosynthesis and respiration do not determine the occurrence of adaptive responses of Symbiodiniaceae to global warming.

Summary Disentangling the metabolic functioning of corals' endosymbionts (Symbiodiniaceae) is relevant to understanding the response of coral reefs to warming oceans. In this work, we first question whether there is an energetic coupling between photosynthesis and respiration in Symbiodiniaceae (Symbiodinium, Durusdinium and Effrenium), and second, how different levels of energetic coupling will affect their adaptive responses to global warming.Coupling between photosynthesis and respiration was established by determining the variation of metabolic rates during thermal response curves, and how inhibition of respiration affects photosynthesis. Adaptive (irreversible) responses were studied by exposing two Symbiodinium species with different levels of photosynthesis–respiration interaction to high temperature conditions (32°C) for 1 yr.We found that some Symbiodiniaceae have a high level of energetic coupling; that is, photosynthesis and respiration have the same temperature dependency, and photosynthesis is negatively affected when respiration is inhibited. Conversely, photosynthesis and respiration are not coupled in other species. In any case, prolonged exposure to high temperature caused adjustments in both photosynthesis and respiration, but these changes were fully reversible.We conclude that energetic coupling between photosynthesis and respiration exhibits wide variation amongst Symbiodiniaceae and does not determine the occurrence of adaptive responses in Symbiodiniaceae to temperature increase.