Climate change does not impact the water flow of barley at the vegetative stage, ameliorates at anthesis and worsens after subsequent drought episodes.

Climate change will bring the interaction of stresses such as increased temperature and drought under high [CO2] conditions. This is likely to impact on crop growth and productivity. This study aimed to (i) determine the response of barley water relations to vegetative and anthesis drought periods under triple interaction conditions, (ii) test the possibility to prime barley plants for drought, and (iii) analyse the involvement of aquaporins in (i) and (ii). The water status of barley was not affected by drought at the vegetative stage, regardless of the environmental conditions. At the anthesis stage, when the water shortage period was more severe, barley plants growing under combined elevated CO2 and temperature conditions were able to maintain a better water status compared with plants grown under current conditions. Elevated CO2 and temperature conditions reduced the stomatal conductance and slowed down the plant water flow through a root-leaf hydraulic conductivity coordination. Leaf HvPIP2;1 and HvTIP1;1 aquaporins seemed to play a key role regulating barley's water flow, while leaf and root HvPIP2;5 provided basic level of water flow. At anthesis drought and under future combined conditions, plants showed a reduced cell dehydration and decrease in leaf relative water content compared with plants grown under current conditions. Exposure to a previous drought did not prime the water status of barley plants to a subsequent drought, but instead worsened the response under future conditions. This was due to an imbalance between the roots versus shoot development.

Spontaneous reoccurrence of Batrachochytrium dendrobatidis infections in Australian green tree frogs (Litoria caerulea) following apparently successful heat therapy: Case report.

Heat therapy has been reported as a safe, effective, and readily available treatment method for heat-tolerant frogs infected with Batrachochytrium dendrobatidis (Bd). We treated wild-caught Australian green tree frogs (Litoria caerulea) infected with Bd using two periods of elevated ambient room temperature (28.2-30.3 °C for 7 weeks followed by 28.9-34.1 °C for 4 weeks). Frogs exhibited persistent and even increasing infection loads in the first treatment period despite prolonged exposure to elevated temperatures, likely due to the presence of cooler microenvironments within their enclosure (25.5-27.0 °C). All frogs eventually returned negative qPCR tests for Bd at the end of the second treatment period, but detectable infections reoccurred one month after frogs were returned to standard housing temperatures (21.2-28.7 °C). Our findings suggest that elevated ambient temperature alone might not eliminate Bd in vivo but can reduce infections loads such that they are undetectable by qPCR analysis of skin swabs. Additional factors, such as cooler microenvironments within enclosures or relative humidity, may influence the success of heat therapy. We recommend further research into the combined effects of temperature and humidity during heat therapy and emphasize the importance of accurate temperature measurements as well as post-treatment monitoring at Bd-permissive temperatures to confirm successful clearance of infections.

Forecasting residual mechanical properties of hybrid fibre-reinforced self-compacting concrete (HFR-SCC) exposed to elevated temperatures.

The use of hybrid fibre-reinforced Self-compacting concrete (HFR-SCC) has escalated recently due to its significant advantages in contrast to normal concrete such as increased ductility, crack resistance, and eliminating the need for compaction etc. The process of determining residual strength properties of HFR-SCC after a fire event requires rigorous experimental work and extensive resources. Thus, this study presents a novel approach to develop equations for reliable prediction of compressive strength (cs) and flexural strength (fs) of HFR-SCC using gene expression programming (GEP) algorithm. The models were developed using data obtained from internationally published literature having eight inputs including water-cement ratio, temperature, fibre content etc. and two output parameters i.e., cs and fs. Also, different statistical error metrices like mean absolute error (MAE), coefficient of determination ( R 2 ) and objective function (OF) etc. were employed to assess the accuracy of developed equations. The error evaluation and external validation both approved the suitability of developed models to predict residual strengths. Also, sensitivity analysis was performed on the equations which revealed that temperature, water-cement ratio, and superplasticizer are some of the main contributors to predict residual compressive and flexural strength.

Elevated temperature and decreased salinity impacts on exogenous Vibrio parahaemolyticus infection of eastern oyster, Crassostrea virginica.

Anthropogenic carbon emissions have resulted in drastic oceanic changes, including increased acidity, increased temperature, and decreased salinity. Anthropogenic carbon emissions have resulted in drastic oceanic changes, including increased acidity, increased temperature, and decreased salinity. Few studies have directly assessed the compounded impact of alterations to oceanic conditions on oyster physiology and the relation to the presence of V. parahaemolyticus. This project investigated the relationship between projected climate scenarios and their influence on both eastern oyster, Crassostrea virginica, and the aquatic bacteria, Vibrio parahaemolyticus. Specifically, we examined whether an increase in water temperature and/or decrease in salinity would impair oyster resistance to V. parahaemolyticus, a human food and waterborne pathogen. Using a culture-dependent approach, our data revealed that the alterations in environmental conditions did not significantly impact the numbers of V. parahaemolyticus numbers within oyster hemolymph or tissues. However, we did observe a dramatic increase in the total amount of bacteria and pathogenic native Vibrio species, Vibrio aestuarianus and Vibrio harveyi. Despite detecting V. parahaemolyticus in most tissues at 7 days post-challenge, oysters were able to reduce bacterial levels below our limit of detection by 28 days of exposure. Furthermore, in our second experimental trial exploring single vs. multiple inoculation of bacteria, we observed that oysters were either able to reduce total bacterial levels to pre-treatment burdens (i.e., below our limit of detection) or die. This study demonstrates that the synergistic effects of elevated temperature and decreased salinity do not inhibit oysters from preventing the long-term colonization of exogenous V. parahaemolyticus. However, our data do show these environmental stressors impact oyster physiology and the native microbiota. This can lead to the proliferation of opportunistic pathogens, which could have impacts on oyster population numbers and ecosystem and human health.

Dramatic loss of microbial viability in bentonite exposed to heat and gamma radiation: implications for deep geological repository.

Bentonite is an integral part of the engineered barrier system (EBS) in deep geological repositories (DGR) for nuclear waste, but its indigenous microorganisms may jeopardize long-term EBS integrity. To predict microbial activity in DGRs, it is essential to understand microbial reactions to the early hot phase of DGR evolution. Two bentonites (BCV and MX-80) with varied bentonite/water ratios and saturation levels (compacted to 1600 kg.m- 3 dry density/powder/suspension), were subjected to heat (90-150 °C) and irradiation (0.4 Gy.h- 1) in the long-term experiments (up to 18 months). Molecular-genetic, microscopic, and cultivation-based techniques assessed microbial survivability. Exposure to 90 °C and 150 °C notably diminished microbial viability, irrespective of bentonite form, with negligible impacts from irradiation or sample type compared to temperature. Bentonite powder samples exhibited microbial recovery after 90 °C heating for up to 6 months but not 12 months in most cases; exposure to 150 °C had an even stronger effect. Further long-term experiments at additional temperatures combined with the mathematical prediction of temperature evolution in DGR are recommended to validate the possible evolution and spatial distribution of microbially depleted zones in bentonite buffer around the waste canisters and refine predictions of microbial effects over time in the DGR.

Multigenerational resilience of the marine rotifer Brachionus plicatilis to high temperature after additive exposure to high salinity and nanoplastics.

To study multigenerational resilience to high temperature (HT) conditions, we exposed Brachionus plicatilis marine rotifers to HT, high salinity (HS), and nanoplastics (NPs), and measured reproductive and life-cycle endpoints. After exposure to HT, rotifer lifespans were reduced, but daily production of offspring increased. However, both combined HT/HS and HT/HS/NP exposure led to additional decreases in longevity and reproductive ability; the antioxidant defense mechanisms of the rotifers were also notably upregulated as measured by reactive oxygen species levels. Fatty-acid profiles were reduced in all conditions. In multigenerational experiments, the negative effects of HT dissipated rapidly; however, the effects of HT/HS and HT/HS/NPs required four generations to disappear completely. The findings indicated that B. plicatilis were able to recover from these environmental stressors. This study demonstrated the resilience of aquatic organisms in response to changing environmental conditions and provides insights into the complex interactions of different abiotic stressors.

Inhibiting Dissolution of Active Sites in 80 °C Alkaline Water Electrolysis by Oxyanion Engineering.

Commercial alkaline water electrolysers typically operate at 80 °C to minimize energy consumption. However, NiFe-based catalysts, considered as one of the most promising candidates for anode, encounter the bottleneck of high solubility at such temperatures. Herein, we discover that the dissolution of NiFe layered double hydroxides (NiFe-LDH) during operation not only leads to degradation of anode itself, but also deactivates cathode for water splitting, resulting in decay of overall electrocatalytic performance. Aiming to suppress the dissolution, we employed oxyanions as inhibitors in electrolyte. The added phosphates to the electrolyte inhibit the loss of NiFe-LDH active sites at 400 mA cm-2 to 1/3 of the original amount, thus reducing the rate of performance decay by 25-fold. Furthermore, the usage of borates, sulfates, and carbonates yields similar results, demonstrating the reliability and universality of the active site dissolution inhibitor, and its role in elevated water electrolysis.

Energy-Based Unified Models for Predicting the Fatigue Life Behaviors of Austenitic Steels and Welded Joints in Ultra-Supercritical Power Plants.

The development of a cost-effective and accurate model for predicting the fatigue life of materials is essential for designing thermal power plants and assessing their structural reliability under operational conditions. This paper reports a novel energy-based approach for developing unified models that predict the fatigue life of boiler tube materials in ultra-supercritical (USC) power plants. The proposed method combines the Masing behavior with a cyclic stress-strain relationship and existing stress-based or strain-based fatigue life prediction models. Notably, the developed models conform to the structure of the modified Morrow model, which incorporates material toughness (a temperature compensation parameter) into the Morrow model to account for the effects of temperature. A significant advantage of this approach is that it eliminates the need for tensile tests, which are otherwise essential for assessing material toughness in the modified Morrow model. Instead, all material constants in our models are derived solely from fatigue test results. We validate our models using fatigue data from three promising USC boiler tube materials-Super304H, TP310HCbN, and TP347H-and their welded joints at operating temperatures of 500, 600, and 700 °C. The results demonstrate that approximately 91% of the fatigue data for all six materials fall within a 2.5× scatter band of the model's predictions, indicating a high level of accuracy and broad applicability across various USC boiler tube materials and their welded joints, which is equivalent to the performance of the modified Morrow model.

Tensile and High Cycle Fatigue Performance at Room and Elevated Temperatures of Laser Powder Bed Fusion Manufactured Hastelloy X.

The application potential of additive manufacturing nickel-based superalloys in aeroengines and gas turbines is extensive, and evaluating their mechanical properties is crucial for promoting the engineering application in load-bearing components. In this study, Hastelloy X alloy was prepared using the laser powder bed fusion process combined with solution heat treatment. The tensile and high cycle fatigue properties were experimentally investigated at room temperature as well as two typical elevated temperatures, 650 °C and 815 °C. It was found that, during elevated-temperature tensile deformation, the alloy exhibits significant serrated flow behavior, primarily observed during the initial stage of plastic deformation at 650 °C but occurring throughout the entire plastic deformation process at 815 °C. Notably, when deformation is small, sawtooth fluctuations are significantly higher at 815 °C compared to 650 °C. Irregular subsurface lack of fusion defects serve as primary sources for fatigue crack initiation in this alloy including both single-source and multi-source initiation mechanisms; moreover, oxidation on fracture surfaces is more prone to occur at elevated temperatures, particularly at 815 °C.

The influence of nanosunflower ash and nanowalnut shell ash on sustainable lightweight self-compacting concrete characteristics.

The absence of biodegradability exhibited by plastics is a matter of significant concern among environmentalists and scientists on a global scale. Therefore, it is essential to figure out potential pathways for the use of recycled plastics. The prospective applications of its utilisation in concrete are noteworthy. The use of recycled plastic into concrete, either as a partial or complete substitution for natural aggregates, addresses the issue of its proper disposal besides contributing to the preservation of natural aggregate resources. Furthermore, the use of agricultural wastes has been regarded as a very promising waste-based substance in the industry of concrete manufacturing, with the aim of fostering the creation of an environmentally sustainable construction material. This paper illustrates the impact of nano sunflower ash (NSFA) and nano walnut shells ash (NWSA) on durability (compressive strength and density after exposure to 800 °C and sulphate attack), mechanical properties (flexural, splitting tensile and compressive strength) and fresh characteristics (slump flow diameter, T50, V-funnel flow time, L-box height ratio, segregation resistance and density) of lightweight self-compacting concrete (LWSCC). The waste walnut shells and local Iraqi sunflower were calcinated at 700 ± 50 °C for 2 h and milled for 3 h using ball milling for producing NSFA and NWSA. The ball milling succeeded in reducing the particle size lower than 75 nm for NSFA and NWSA. The preparation of seven LWSCC concrete mixes was carried out to obtain a control mix, three mixtures were created using 10%, 20% and 30% NWSA, and the other three mixtures included 10%, 20% and 30% NSFA. The normal weight coarse aggregates were substituted by the plastic waste lightweight coarse aggregate with a ratio of 75%. The fresh LWSCC passing capacity, segregation resistance, and filling capability were evaluated. The hardened characteristics of LWSCC were evaluated by determining the flexural and splitting tensile strength at 7, 14 and 28 days and the compressive strength was measured at 7, 14, 28 and 60 days. Dry density and compressive strength were measured after exposing mixes to a temperature of 800 °C for 3 h and immersed in 10% magnesium sulphate attack. The results demonstrated that the LWSCC mechanical characteristics were reduced when the percentages of NWSA and NSFA increased, except for 10% NWSA substitution ratio which had an increase in splitting tensile strength test and similar flexural strength test to the control mixture. A minor change in mechanical characteristics was observed within the results of LWSCC dry density and compressive strength incorporating various NSFA and NWSA` contents after exposing to temperature 800 °C and immersed in 10% magnesium sulphate attack. Furthermore, according to the findings, it is possible to use a combination of materials consisting of 10-20% NSFA and 10-20% NWSA to produce LWSCC.

Assessing the impact of climate change on water requirement and yield of sugarcane over different agro-climatic zones of Tamil Nadu.

The DSSAT CANEGRO model was calibrated and verified using field experimental data from five Tamil Nadu Agroclimatic Zones (1981-2022). The genetic coefficients of the sugarcane cultivar (CO-86032) were calculated. R2 obtained between measured and simulated stalk fresh mass was 0.9 with the nRMSE (0.01) and RMSE (1.6) and R2 between measured and simulated sucrose mass was 0.9 with the nRMSE (0.16) and RMSE (1.2). For yield R2 obtained between measured and simulated was 0.9 with the nRMSE (0.01) and RMSE (1.6). As a result, the CANEGRO model may be used to mimic the phenology and yield features of the sugarcane cultivar in Tamil Nadu's Agro Climatic Zones. Temperature increases in Agro Climatic Zones resulted in varying yield reductions, with 2 °C increases causing a 3% loss, 3 °C increases 5%, and 4 °C increases 9%. The Water Requirement rose throughout all of the ACZ due to the high temperature, but to differing degrees. A 2 °C increase often results in an average 4% increase in the WR. 3 °C rise in temperature increased WR to 9% and WR rose by 13% when the temperature was raised by 4 °C.

Perovskite for Electrocatalytic Oxygen Evolution at Elevated Temperatures.

The development of advanced electrolysis technologies such as anion exchange membrane water electrolyzer (AEMWE) is central to the vision of a sustainable energy future. Key to the realization of such AEMWE technology lies in the exploration of low-cost and high-efficient catalysts for facilitating the anodic oxygen evolution reaction (OER). Despite tremendous efforts in the fundamental research, most of today's OER works are conducted under room temperature, which deviates significantly with AEMWE's operating temperature (50-80 °C). To bridge this gap, it is highly desirable to obtain insights into the OER catalytic behavior at elevated temperatures. Herein, using the well-known perovskite catalyst Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) as a proof of concept, the effect of temperature on the variation in OER catalytic activity and stability is evaluated. It is found that the BSCF's activity increases with increasing temperature due to enhanced lattice oxygen participation promoting the lattice oxygen-mediated OER process. Further, surface amorphization and cation leaching of BSCF become more pronounced as temperature increases, causing a somewhat attenuated OER stability. These new understandings of the fundamental OER catalysis over perovskite materials at industrial-relevant temperature conditions are expected to have strong implications for the research of OER catalysts to be deployed in practical water electrolyzers.

Short-term residual characteristics of ambient-cured green geopolymer mortar exposed to elevated temperatures.

Every structure might be exposed to fire at some point in its lifecycle. The ability of geopolymer composites to withstand the effects of fire damage early before it is put out is of great importance. This study examined the effects of fire on geopolymer composite samples made with high-calcium fly ash and alkaline solution synthesised from waste banana peduncle and silica fume. A ratio of 0.30, 0.35, and 0.4 was used in the study for the alkaline solution to fly ash. Also used were ratios of 0.5, 0.75, and 1 for silica oxide (silica fume) to potassium hydroxide ratio. The strength loss, residual compressive strength, percentage strength loss, relative residual compressive strength, ultrasonic pulse velocity, and microstructural properties of the thirteen mortar mixes were measured after exposure to temperatures of 200, 400, 600, and 800 °C for 1 h, respectively. The results reveal that geopolymer samples exposed to elevated temperatures showed great dimensional stability with no visible surface cracks. There was a colour transition from dark grey to whitish brown for the green geopolymer mortar and brown to whitish brown for the control sample. As the temperature rose, weight loss became more pronounced, with 800 °C producing the most significant weight reduction. The optimum mixes had a residual compressive strength of 25.02 MPa after being exposed to 200 °C, 18.72 MPa after being exposed to 400 °C, 14.04 MPa after being exposed to 600 °C, and 7.41 MPa after being exposed to 800 °C. The control had a residual compressive strength of 8.45 MPa after being exposed to 200 °C, 6.67 MPa after being exposed to 400 °C, 3.16 MPa after being exposed to 600 °C, and 2.23 MPa after being exposed to 800 °C. The relative residual compressive strength decreases for green geopolymer mortar are most significant at 600 and 800 °C, with an average decrease of 0.47 and 0.30, respectively. The microstructure of the samples revealed various phase changes and new product formations as the temperature increased.

Morphometric and Enzymatic Changes in Gills of Rainbow Trout after Exposure to Elevated Temperature-Indications for Gill Remodeling.

Seven-month-old rainbow trout acclimated to 9 °C were used. The fish were gradually adapted to a water temperature of 20 °C over a period of seven days and then exposed to this temperature for 32 days. Changes in gill morphometry and histology and in enzyme activities in comparison to fish kept at 9 °C were investigated. No histopathological abnormalities were discerned at the heightened temperature. The gill epithelium thickened by approximately 40%, suggesting an increase in the branchial diffusion barrier for ions, water, and gases. Concurrently, there was a significant decrease in the activities of gill H+-ATPase and Na+/K+-ATPase, indicative of a reduction in osmoregulation under elevated temperatures. Carbonic anhydrase activity exhibited an increase following the 32-day exposure to 20 °C, potentially mitigating the adverse effects of increased gill epithelium thickness on gaseous exchange. There were no indications of gill surface enlargement as the measurements of the length of the primary and secondary lamellae, as well as of the distances between them, were similar at 9 and 20 °C. The activities of the gill enzymes associated with glycolysis and the citric acid cycle displayed a varied response following the 32-day exposure of rainbow trout to 20 °C. Pyruvate kinase decreased, while lactate dehydrogenase increased, and malate dehydrogenase remained constant. This might suggest a decrease in the glycolytic rate, a greater reliance on anaerobic pathways at 20 °C compared to 9 °C, and the consistent efficiency of the citric acid cycle in the gills of rainbow trout in response to elevated temperatures. In summation, the data suggest a remodeling of rainbow trout gills in response to elevated temperatures, affecting both morphometric and metabolic aspects.

A state-of-the-art review of the physical and durability characteristics and microstructure behavior of ultra-high-performance geopolymer concrete.

This paper provides a comprehensive review of ultra-high-performance geopolymer concrete (UHPGPC), an innovative, eco-friendly, and cost-effective variant of ultra-high-performance concrete (UHPC), devised to meet the rising request for ultra-high-strength construction materials. Previous research papers have not thoroughly analyzed and compared the rheological, physical, durability, and microstructural properties of UHPGPC with UHPC. Similarly, review articles scarcely investigate UHPGPC's strength properties and microstructural behavior under high temperatures. This paper includes an assessment of the correlation between compressive strength, splitting tensile strength, and modulus of elasticity (MOE). The current study also compares chloride ion penetration test outcomes, elevated temperature, electrical resistivity, and porosity tests to evaluate durability. To analyze the microstructure of UHPGPC, the paper assesses results from Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), and Mercury Intrusion Porosimetry (MIP). The findings from the present paper suggest that UHPGPC effectively meets the ideal mechanical property specifications of UHPC. Compared to UHPC, UHPGPC displayed a higher ion passage propensity due to larger pores (>100 nm). Geopolymer technologies present a greener path for producing UHPC by consuming less energy and emitting reduced CO2. Introducing mineral fillers like silica fume impacts the mixture's flowability and increases its water needs. However, adding an optimal ratio of micro-silica as a partial substitute for granulated blast furnace slag further bolsters the strength characteristics of UHPGPC. The strength of UHPC can also be notably improved by adjusting the water-to-binder ratio, with specific ratios yielding considerable enhancements in compression strength. The selection of an alkaline activator plays a pivotal role in UHPC's heat resilience. Among them, a combination of potassium hydroxide and sodium silicate is the prime chemical activator for boosting strength performance, durability behavior, and microstructural attributes, particularly at temperatures beyond 600 °C. Eco-friendly Geopolymer Composites (EGCs) offer lower embodied energy and CO2 emissions than traditional composites, with certain components like polyvinyl alcohol fibers being key contributors to these emissions. Progress in self-healing materials is driving sustainability in construction through innovative techniques, such as bacterial applications and specific chemical reactions. The strength and workability of Engineered Geopolymer Composites are influenced by their fiber content, with certain fibers interacting weaker than others. On a microstructural level, UHPGPC has a relatively weaker structure than UHPC due to differences in pore size, but its durability is improved when reinforced with fibers.

Effects of temperature and nitrogen sources on physiological performance of the coccolithophore Emiliania huxleyi.

Both temperature and nutrient levels are rising in worldwide ocean ecosystems, and they strongly influence biological responses of phytoplankton. However, few studies have addressed the interactive effects of temperature and nitrogen sources on physiological performance of the coccolithophore Emiliania huxleyi. In this study, we evaluated algal growth, photosynthesis and respiration, elemental composition, enzyme activity, and calcification under a matrix of two temperatures gradients (ambient temperature 20 °C and high temperature 24 °C) and two nitrogen sources (nitrate (NO3-) and ammonium (NH4+)). When the algae was cultured with NO3- medium, high temperature reduced algal photosynthesis and nitrate reductase activity, but it did not change other indicators significantly relative to ambient temperature. In addition, E. huxleyi preferred NO3- as the growth medium, whereas NH4+ had negative effects on physiological parameters. In the NH4+ medium, the growth rate, photosynthesis and photosynthetic rate, nitrate reductase activity, and particulate organic carbon and particulate organic nitrogen production rate of the algae decreased as temperature increased. Conversely, high temperature increased cellular particulate organic carbon, cellular particulate organic nitrogen, and particulate inorganic carbon levels. In summary, our findings indicate that the distribution and abundance of microalgae could be greatly affected under warming ocean temperature and different nutrient conditions.

The novel chaperonin 10 like protein (SbCPN10L) from Salicornia brachiata (Roxb.) augment the heat stress tolerance in transgenic tobacco.

The heat stress is a significant environmental challenge and impede the plant growth, development and productivity. The characterization and utilization of novel genes for improving stress tolerance represents a paramount approach in crop breeding. In the present study, we report on cloning of a novel heat-induced chaperonin 10-like gene (SbCPN10L) from Salicornia brachiata and elucidation of its in-planta role in conferring the heat stress endurance. The transgenic tobacco over-expressing SbCPN10L gene exhibited enhanced growth attributes such as higher rate of seed germination, germination and vigor index at elevated (35 ± 1 °C) temperature (eT). The SbCPN10L tobacco exhibited greenish and healthy seedling growth under stress. Compared with control tobacco at eT, the transgenic tobacco had higher water contents, membrane stability index, stress tolerance index and photosynthetic pigments. Lower electrolyte leakage and less accumulation of malondialdehyde, hydrogen peroxide and reactive oxygen species indicated better heat stress tolerance in transgenic tobacco over-expressing SbCPN10L gene. Transgenic tobacco accumulated higher contents of sugars, starch, amino acids and polyphenols at eT. The negative solute potential observed in transgenic tobacco contributed to maintain water content and support improved growth under stress. The up-regulation of NtAPX, NtPOX and NtSOD in transgenic tobacco under stress indicated higher ROS scavenging ability and better physiological conditioning. The results recommend the SbCPN10L gene as a potential candidate gene with an ability to confer heat stress tolerance for climate resilient crops.

Effects of elevated temperature and different crystal structures of TiO2 nanoparticles on the gut microbiota of mussel Mytilus coruscus.

Coastal habitats are exposed to increasing pressure of nanopollutants commonly combined with warming due to the seasonal temperature cycles and global climate change. To investigate the toxicological effects of TiO2 nanoparticles (TiO2 NPs) and elevated temperature on the intestinal health of the mussels (Mytilus coruscus), the mussels were exposed to 0.1 mg/L TiO2 NPs with different crystal structures for 14 days at 20 °C and 28 °C, respectively. Compared to 20 °C, the agglomeration of TiO2 NPs was more serious at 28 °C. Exposure to TiO2 NPs led to elevated mortality of M. coruscus and modified the intestinal microbial community as shown by 16S rRNA sequence analysis. Exposure to TiO2 NPs changed the relative abundance of Bacteroidetes, Proteobacteria and Firmicutes. The relative abundances of putative mutualistic symbionts Tenericutes and Fusobacteria increased in the gut of M. coruscus exposed to anatase, which have contributed to the lower mortality in this group. LEfSe showed the combined stress of warming and TiO2 NPs increased the risk of M. coruscus being infected with potential pathogenic bacteria. This study emphasizes the toxicity differences between crystal structures of TiO2 NPs, and will provides an important reference for analyzing the physiological and ecological effects of nanomaterial pollution on bivalves under the background of global climate change.

Using landfill leachate to indicate the chemical and biochemical activities in elevated temperature landfills.

Landfill leachate properties contain important information and can be a unique indicator for the chemical and biochemical activities in landfills. In the recent decade, more landfills are experiencing elevated temperature, causing an imbalance in the decomposition of solid waste and affecting the properties of the landfill leachate. This study analyzes the properties of leachate from two landfills that were experiencing elevated temperature (ETLFs), samples were collected from both elevated temperature impacted and non-impacted areas in each landfill. The accumulation of volatile fatty acids (VFA) in leachates from elevated temperature impacted areas of both landfill sites revealed that methanogenesis was inhibited by the elevated temperature, which was further confirmed by the more acidic pH, higher H/C elemental ratio, and lower degree of aromaticity of the elevated temperature impacted leachates. Also, carbohydrates depletion indicated possible enhancement of hydrolysis and acidogenesis by elevated temperature, which was supported by compositional comparison of isolated acidic species by negative-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICRMS) at 21 T derived from both elevated temperature impacted and non-impacted areas in the same landfill site. Furthermore, leachate organics fractionation showed that leachates not impacted by elevated temperature contain less hydrophilic fraction and more humic fraction than elevated temperature-impacted leachates for both ETLFs.

Effects of elevated temperature and copper exposure on the physiological state of the coral Galaxea fascicularis.

The co-occurrence of elevated seawater temperature and local stressors (heavy metal contamination) affects the ecophysiology of phototrophic species, and represents a risk to the environmental quality of coral reefs. Therefore, we investigated the effects of both Cu alone and Cu in combination with elevated temperature (ET) on the physiology of the coral Galaxea fascicularis, and measured the parameters related to the photo-physiology and oxidative state. G.fascicularis is one of the dominant coral species in the South China Sea which exhibits strong adaptability to environmental stress. We exposed the common coral species G.fascicularis to a series of environmentally relevant concentrations of Cu at 29 °C (normal temperature, NT) and 32 °C (elevated temperature, ET) for 96 h. Single polyps were used in the experiments, which reduced individual variability when compared to the coral colonies. The results suggested that: i) Cu or ET had significant negative effects on the actual operating ability of photosystem Ⅱ (PSII), but not on the maximal chlorophyll fluorescence in darkness (Fv/Fm). ii) Symbiodiniaceae density was significantly reduced by high Cu concentrations, for Cu-NT and Cu-ET, a high concentration of Cu (40 µg/L) significantly impacted Symbiodiniaceae density, causing a 75.4% and 81.0% decrease, respectively. iii) the content of malondialdehyde (MDA) in coral tissues increased significantly under Cu-ET. iv) a certain range of copper concentration (25-30 µg/L) increased the pigment content of the Symbiodiniacea. Our results indicated that the combined stressors of Cu and ET made the coral tissue sloughed, caused the coral tissue damaged by lipid oxidation, reduced the photosynthetic capacity of the Symbiodiniacea, and led to the excretion of Symbiodiniacea.