Effects Of Temperature Stress Research Articles

The effects of different thermal and chemical stresses on release of outer membrane vesicles (OMVs) by ClearColi™.

The highly immunogenic properties of outer membrane vesicles (OMVs), small spherical nanoparticles commonly released by Gram-negative bacteria, led to their application as vaccine candidate. ClearColi™ is an engineered Escherichia coli strain, which does not produce endotoxic response in humans and is useful for production of OMV-based vaccines. Therefore, producing ClearColi™ OMVs with high yield attracts particular interest. As stresses can be removed by OMVs, they may affect OMVs release. We aimed to investigate the effects of culture temperature, chemical (NaCl, ethanol, EDTA, D-cycloserine, polymyxin B, 1-octanol, and H2O2) and thermal stresses on release of ClearColi™ OMVs. Herein, the growth rate of ClearColi™ was decreased in the presence of all chemical stresses with the exception of H2O2. The optimum temperature for OMVs production was 37℃ and their release was not increased under thermal shock. The highest and lowest OMVs release was obtained in the presence of NaCl and H2O2, respectively. Electron microscopy images confirmed that the bilayer spherical-shaped OMVs were isolated under different stresses. Furthermore, SEM and DLS analysis demonstrated that OMVs released under EDTA stress are smaller than those released from untreated cultures. It can be concluded that chemical stresses have influence on the level of ClearColi™ OMVs production. However, changes in their content should be further investigated.

Anomalies in precipitation rather than temperature as the dominant driver of drought stress on vegetation in the Northern Hemisphere

Climate warming has substantially increased drought-induced reduction in terrestrial productivity over recent decades. However, important questions regarding the primary driver of drought stress remain controversial under the context of global warming. The period of warming hiatus between 1998 and 2013 provides a unique opportunity to understand the relative importance of temperature and precipitation anomalies to drought stress on terrestrial ecosystems. Here we analyzed and compared the effects of temperature, precipitation and drought stress on vegetation productivity before and over the warming hiatus period. We found that precipitation anomalies rather than temperature are the primary driver of drought and associated decreased productivity with warming in the Northern Hemisphere. Our study implied that the weight of precipitation and temperature should be adjusted when modeling the drought stress on terrestrial ecosystems under future climate warming scenarios. Data AvailabilityThe data that support the findings of this study are openly available: ORNL DAAC (http://daac.ornl.gov;https://doi.org/10.3334/ORNLDAAC/1789); CRU (https://crudata. uea.ac.uk/cru/data/hrg/; http://doi.org/10.1002/joc.3711).

Dipole modelling of temperature-dependent magnetic flux leakage

Due to the nonlinear coupling, assessing the direct effect of temperature on magnetic flux leakage (MFL) signal is a complicated task. If temperature induces inner stress, it makes the problem doubly difficult, so few models are available for predicting the MFL signal under this condition. To model the effect of temperature on MFL signal, the temperature-dependent magnetic dipole models are proposed. In the first case, where the direct thermal effect is involved only, the dipole model is improved via the modified temperature-dependent Jiles-Atherton (J-A) model. While in the second case, where the combined effects of temperature and thermal stress are considered, the magnetomechanical J-A parameters are further introduced into the dipole model. The thermal stress distribution around a cylindrical through-hole defect is solved by thermoelastic and solid mechanics theories. The magnetomechanical theory is employed to analyse the stress-dependent magnetisation distribution, the key parameter in the magnetic dipole model. The verified experiments are conducted on an M250-50A non-oriented grain (NO) silicon steel specimen with a cylindrical through-hole defect. And the MFL signals predicted by both proposed models agree with the experimental results. When the direct effect of temperature is involved only, the peak-to-peak amplitude of the MFL signal (MFLpp) presents approximately linear dependence on temperature in the range from −40 °C to 60 °C. In addition, when both temperature and thermal stress are considered, the MFLpp changes as a parabolic function of temperature, this being much more significant than the direct effect. The proposed models can act as effective tools to understand the temperature and thermal stress influences on MFL signals. They are also appropriate to solve the inverse problem of sizing the defects accurately when the temperature is involved.

Effect of long-term temperature stress on the intestinal microbiome of an invasive snail.

The gut microbiome is vital to the physiological and biochemical functions of the host, and changes in the composition of these microbial communities may affect growth and adaptability to the environment. Pomacea canaliculata is an invasive freshwater snail which has become a serious agricultural pest. Temperature adaptation is considered an important reason for the widespread distribution of this species. To date, the contribution of the gut microbes to host fitness of P. canaliculata during long-term temperature stress is not well understood. In this study, the morphological changes and intestinal microbiome of P. canaliculata under long-term stress at low temperature (15°C) and high temperature (35°C) were investigated with laboratory experiments. Compared with control group (25°C), the alpha diversity increased and pathogenic bacteria enriched changed under high and low temperature stress. The effect of high temperature stress on the intestinal microbiome of P. canaliculata was more significant than that of low temperature stress. A sustained high temperature environment led to an increase in the abundance of pathogenic bacteria, such as Aeromonas and Enterobacter, and a decrease in the abundance of immune-related bacteria such as Bacteroidetes, Firmicutes, and Lactococcus. These intestine microbiome changes can increase the risk of diseases like intestinal inflammation, and lead to more deaths at high temperature environments. In addition, with the extension of stress time from 14 to 28 days, the beneficial bacteria such as Bacteroidetes, Firmicutes, and Lactococcus were significantly enriched, while potential pathogenic bacteria such as Pseudomonas, Acinetobacter, Shivalella, and Flavobacterium decreased, suggesting that intestinal microbiota may play an important role in host response to heat stress. These results are consistent with previously reported results that the survival rate of both male and female P. canaliculata no longer significantly reduced after 21 days of high temperature stress, suggesting that the surviving P. canaliculata had gradually adapted to high temperature environments under long-term high temperature stress.

The potential roles of fatty acid metabolism-related genes in Manila clam Ruditapes philippinarum under cold stress

Temperature is an important factor that affects geographic distribution, reproduction, and physiological processes of organisms. In this study, we used quantitative PCR to analyze the effects of low temperature stress (5 °C and − 2 °C) on the expression of fatty acid metabolism-related genes in different tissues of two wild populations(southern and northern) and three shell color strains (zebra, white, and white zebra) of the Manila clam, Ruditapes philippinarum. We found that fatty acid synthase-related genes were expressed in all examined tissues (gill, mantle, adductor muscle, gonad, digestive gland, foot, and siphon), with the highest expression level in the digestive gland and gills. The fatty acid metabolism-related genes acetyl-CoA carboxylase (ACC), elongation of very long chain fatty acids protein 6 (ELOVL6), fatty acid desaturase (FAD),and fatty acid synthase-like (FAS) were highly expressed in the northern clams, and the expression levels differed significantly between the northern population and the zebra strain (P < 0.05). Our results provided useful information about the response of fatty acid metabolism-related genes in Manila clams to low temperature stress, which could be helpful for improving the cold stress resistance of these clams in the aquaculture industry.

Effect of temperature stress on Brassica rapa genotypes during germination and reproductive growth

The effect of temperature stress on the reproductive development and yield of five Brassica rapa was studied in a controlled growth chamber. The seeds of five Brassica genotypes namely BARI Sarisha-6, Tori 7, Kallayania, BARI Sarisha-9 and BINA Sarisha-4 were grown under day/night temperatures at 22/170C until early flowering or early siliqua development stage. The high temperature stress i.e., 28 /170C or 35/170C, both at early flowering stage and early siliqua formation stage were imposed for 7d and then allowed to recover at 22/170C for normal growth. Shoot dry matter accumulation varied with temperature and genotype. The highest shoot dry matter was recorded by Kallayania followed by BARI Sarisha-9. The optimum day temperature for seed yield of the main shoot showed closer to 280C. The largest seeds were produced in the 22/170C, the size, however, remained similar with 28/170C temperature stress. During this temperature regime, the highest seed yield was observed with BARI Sarisha-6 while BARI Sarisha-9 produced the lowest seed yield. Severe temperature stress (35/170C) reduced seeds per siliqua and 1000 seed weight in all genotypes. Maximum pollen viability and germination were recorded at 200C by Kallayania followed by Tori 7 at 250C. However, the temperature above 300C reduced pollen viability and germination for all the genotypes. In another set of treatments, the high temperatures exposure (28/230C) for 5d reduced oil content and increased protein concentrations. Plant exposed to 25/200C temperature stress showed significant changes in oleic, linoleic, and linolenic acids. The levels of saturated fatty acids were similar across the five genotypes in the control treatment, but palmitic acid and stearic acids increased with the temperature. Bangladesh J. Agri. 2019-2021, 44-46: 19-29

Meso-structural characteristics of porous asphalt mixture based on temperature-stress coupling and its influence on aggregate damage

This paper studies the meso-structural characteristics of porous asphalt (PA) mixture and the influence of heterogeneity on the overall mechanical and thermal properties of pavement. A porous asphalt mixture model considering the temperature-stress dual-field coupling is developed. The effect of temperature stresses generated during the gradual decrease of the internal temperature of porous asphalt mixture from 25 °C to −25 °C on the micro-cracked inside the aggregate, is simulated using the finite element software. The magnitude of the temperature stress values generated inside the mixture when the internal voids of the porous asphalt mixture are filled with air and water, is analyzed. In order to analyze the tendency of expansion of micro-cracks within the aggregates in asphalt mixes under temperature stress, a macroscopic test of the maximum cooling range is carried out with Marshall specimens, and the simulation results of the finite element software are verified. The results show that when there are micro-cracked aggregates in porous asphalt mixtures, as the temperature of the asphalt mixture decreases, stress concentration occurs at the cracks of the aggregate, and the stress concentration at the end of the aggregate crack is the most obvious. The temperature stress value generated at the crack end of the damaged aggregate first reaches the aggregate crushing value. Under the same cooling amplitude, the stress value generated in the mixture when the voids of the porous asphalt mixture are filled with water is larger than that when the voids are filled with air. Finally, the obtained results have a certain reference value for the study of the damage law of porous asphalt mixture by temperature stress, when the ambient temperature decreases.

Experimental Investigation of Temperature and Contact Pressure Influence on HFI Welded Joint Properties.

This paper presents an experimental electro-thermo-mechanical simulation of high-frequency induction (HFI) welding to investigate the effect of temperature and contact normal stress on the weld seam quality. Therefore welding experiments at different temperatures and contact pressures are performed using flat specimens of 34MnB5 steel sheet. In order to characterize the weld seam strength of the welded specimens, tensile and bending tests are performed. To obtain a relative weld seam strength, the bending specimens were additionally hardened prior to testing. With the hardened specimens, it can be shown that the weld seam strength increases with increasing temperature and contact normal stress until a kind of plateau is formed where the weld seam strength remains almost constant. In addition to mechanical testing, the influence of the investigated process parameters on the weld seam microstructure is studied metallographically using light optical microscopy, scanning electron microscopy, EBSD and hardness measurements. It is shown that the weld seam strength is related to the amount of oxides in the bonding line.

Interactive Effects of Thermal and Salinity Stress Cause Cell Cycle Arrest in the Nile Tilapia

The goal of this study was to test the interactive effects of sub‐lethal thermal stress and environmental salinity variation on a tropical freshwater species, the Nile tilapia, Oreochromis niloticus. This economically important species is vulnerable to increased morbidity at low temperatures, a condition sometimes termed “Winter Stress Syndrome”. It is possible that in addition to extreme weather events, saltwater intrusion into freshwater systems presents physiological challenges to this species. To test this hypothesis, Nile tilapia were exposed to a variety of treatments (two temperatures: 21°C &amp; 14°C, three salinities: 0ppt, 16ppt, 34ppt) for 1‐h. Following exposures, flow cytometry was used to assess cell cycle staging in the spleen and liver. Specifically, we were testing the synergistic effects of temperature and salinity stress on cell cycle arrest and apoptosis, both metrics of sub‐lethal stress and a switch away from growth and towards stress responses. Both liver and spleen responded to temperature and salinity stress by inducing cell cycle arrest in a tissue‐specific manner. Apoptosis was also detected in the spleen. These findings support our hypothesis that the combination of thermal and salinity stress have deleterious impacts on the health of this important global source of protein.

Fatigue Fracture Analysis on 2524 Aluminum Alloy with the Influence of Creep-Aging Forming Processes.

The different creep-aging forming processes of 2524 aluminum alloy were taken as the research object, and the effects of creep-aging temperature and creep stress on the fatigue-crack propagation properties of the alloy were studied. The research results showed the following under the same sintering time of 9 h, at creep-aging temperatures of 100 °C, 130 °C, 160 °C, and 180 °C, respectively, with an increase in creep-aging temperature: the fatigue-crack propagation rate was promoted, the spacing of fatigue striations increased, and the sizes of dimples decreased while the number was enlarged; this proves that the fatigue property of the alloy was weakened. Compared with the specimens with creep deformation radii of 1000 mm and 1500 mm, the creep deformation stress was the smallest when the forming radius was 1800 mm, with a higher threshold value of fatigue-crack growth in the near-threshold region of fatigue-crack propagation (ΔK ≤ 8 MPa·m1/2). Under the same fatigue cycle, the specimens under the action of larger creep stress endured a longer fatigue stable-propagation time and a faster fracture speed. Comparing the effect of creep-aging temperature and creep stress, the creep-aging temperature plays a dominant role in the fatigue-crack propagation of creep-aged 2524 aluminum alloy.

Interactive effect of irrigation and temperature regimes on growth and development of kidney bean (Phaseolus vulgaris L.)

Approximately 60 percent of kidney bean (Phaseolus vulgaris L.) produced in developing countries is cultivated under conditions of drought stress and low fertility/ low input. Coincidence of water and heat stress, which is projected to occur more in changing climates, cause severe yield loss. To quantify the response of kidney bean to water and temperature stress, an experiment was carried under Randomized Block Design in field and temperature gradient tunnel conditions. Temperature treatments included high temperature for entire crop growth period (~4.6℃, ~3.1℃, ~2.8℃ above mean ambient, 19.6℃), ambient temperature, elevated temperature during pre-flowering phase (~3.7℃ above mean ambient during that period, 19.6℃), flowering phase (~5.3℃ above mean ambient during that period, 23.1℃) and pod-filling phase (~5.2℃ above mean ambient during that period, 28.9℃). These were combined with i) two irrigations (applied at sowing and seedling phase) and ii) three irrigations (additional irrigation at pod-filling phase). Results indicated that plants under seasonal mean temperatures of 36.7/11.7℃, 33.9/11.6℃ and 33.1/11.7℃ had shortened crop duration with 73-78 DAS. Findings this study indicated that kidney bean exhibits phenological plasticity response to temperature and water regimes. Seasonal mean temperature of 24.2℃ lead to better performance of the crop while temperature shocks during pre-flowering and flowering significantly reduced seed yield. Additionally, exposure of kidney bean plants to water stress (available soil moisture content &lt;10%) significantly reduced seed yield. Coincidence of temperature stress and water stress had more detrimental effects on seed yield. Given the climate scenarios indicating increased variability in temperature and rainfall, findings from this study indicate that climatic risks mayaffect kidney bean seed yield in future. Strategies such as providing supplemental irrigation can alleviate the negative effects of temperature stress and improve kidney bean yield.

Effect of temperature and osmotic stress during somatic embryogenesis on phenology and physiology of abies nordmanniana emblings

Epigenetic modification induced during embryogenesis can serve as a mechanism for rapid adaptation of plants to climate change, especially for long living organisms such as trees. Here, we test if temperature and osmotic stress during embryogenesis influences spring and autumn phenology, photosynthesis rate, growth and water stress tolerance in Abies nordmanniana. Somatic embryogenic plants (emblings) were developed under different temperatures to test if temperature influences the spring phenology. Our results show that 9 °C higher temperature during somatic embryogenesis advanced budburst by an average of 4 days, but with significant differences among different genotypes in their response. This reveals genetic variation in the observed phenological response to temperature during somatic embryogenesis. However, we did not observe an effect of differences in osmotic stress during somatic embryogenesis on the response of the emblings to water stress. Optimum temperatures for photosynthesis and maximal photosynthetic rates were not found to be influenced by the temperature during somatic embryogenesis. Both height and autumn senescence were significantly different among the genotypes, but the temperature during somatic embryogenesis did not affect these traits. The observed responses in our study complement findings from other species and support that epigenetic modification in phenology may help the species to cope with fluctuations in temperatures in future climate, and may have practical applications for reducing spring frost risk in plantations of the species.

Effects of Temperature and Nitrogen Application on Carbon and Nitrogen Accumulation and Bacterial Community Composition in Apple Rhizosphere Soil.

Malus sieversii grows on the slopes of the Tianshan Mountains in Xinjiang where the difference in daily temperature is significant. In recent years, the rhizosphere soil health of Malus sieversii has been severely impacted by anthropogenic disturbance and pathogenic infestation. The soil nutrient content and soil microorganism diversity are the main components of soil health. Low temperature has negative effects on soil bacterial community structure by inhibiting the accumulation of carbon and nitrogen. However, the effects of temperature and nitrogen application on soil carbon and nitrogen accumulation and the bacterial community composition in the rhizosphere soil of Malus sieversii are unclear. We set two temperature levels, i.e., low temperature (L) and room temperature (R), combined with no nitrogen (N0) and nitrogen application (N1) to explore the response of plant carbon and nitrogen uptake, rhizosphere soil carbon and nitrogen accumulation and bacterial community composition to temperature and nitrogen fertilization. At the same temperature level, plant 13C abundance (P-Atom13C), plant 15N absolute abundance (P-Con15N), soil 15N abundance (S-Atom15N) and soil urease, protease and glutaminase activities were significantly higher under nitrogen application compared with the no-nitrogen application treatment. The bacterial community diversity and richness indices of the apple rhizosphere soil in the N1 treatment were higher than those in the N0 treatment. The relative abundances of Actinobacteria, Rhodopseudomonas, and Bradyrhizobium were higher in the LN1 treatment than in the LN0 treatment. Redundancy analysis (RDA) showed that plant 13C absolute abundance (P-Con13C) and plant 15N absolute abundance (P-Con15N) were the main factors affecting the soil bacterial community composition. In summary, Nitrogen application can alleviate the effects of low temperature stress on the soil bacterial community and is of benefit for the uptakes of carbon and nitrogen in Malus sieversii plants.

The Effect of Temperature and Water Stresses on Seed Germination and Seedling Growth of Wheat (Triticum aestivum L.)

Temperature and moisture are essential factors in germination and seedling growth. The purpose of this research was to assess the germination and growth of wheat (Triticum aestivum L.) seeds under various abiotic stressors. It was conducted in the Agronomy Institute of the Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary. Six distinct temperature levels were used: 5, 10, 15, 20, 25, and 30 °C. Stresses of drought and waterlogging were quantified using 25 water levels based on single-milliliter intervals and as a percentage based on thousand kernel weight (TKW). Seedling density was also tested. Temperature significantly influenced germination duration and seedling development. 20 °C was ideal with optimal range of 15 °C to less than 25 °C. Germination occurred at water amount of 75% of the TKW, and its ideal range was lower and narrower than the range for seedling development. Seed size provided an objective basis for defining germination water requirements. The current study established an optimal water supply range for wheat seedling growth of 525–825 percent of the TKW. Fifteen seeds within a 9 cm Petri dish may be preferred to denser populations.

Effect of short-term temperature stress on fruit set and the expression of an auxin reporter gene and auxin synthesis genes in tomato

• Effect of short-term temperature stress was evaluated during 5 days before anthesis. • Auxin-related factors were investigated using Micro-Tom as a model system. • DR5::GUS expression under high temperature was inhibited with the fruit development. • Fruit set and DR5::GUS expression were not inhibited under low-temperature stress. • The expression of ToFZY for auxin synthesis were affected by high-temperature stress. Poor fruit set and growth are known to be caused by temperature stress in tomato cultivation. We focused on the effect of short-term temperature stress on each day during the five days before anthesis. The relationship between temperature stress and auxin-related factors was investigated using an experimental tomato cultivar, Micro-Tom expressing the auxin reporter DR5::GUS as a model system. While DR5::GUS expression in the control plants increased in ovaries and transferred to peduncles during the later developmental stages, that under high-temperature stress was not detected or very low. Some smaller fruit grew even under high-temperature stress probably due to the low level of DR5::GUS expression. Therefore, it was suggested that temporary high-temperature stress at any stage in this study affected the localization of auxin to ovaries and peduncles, and further affected fruit set and growth. By contrast, no decreased fruit set was observed with some delay and recovery of fruit growth under low-temperature stress, and this corresponded to the levels of DR5::GUS expression. The expression of GUS with the promoter of the tomato PIN gene, which is involved in the auxin transport, was not affected by high-temperature stress. On the other hand, the expression of ToFZY genes involved in auxin synthesis were affected by temperature stress, suggesting a part of the mechanism of the decrease in DR5::GUS expression under high-temperature stress.

Seed Germination and Seed Bank Dynamics of Eruca sativa (Brassicaceae): A Weed on the Northeastern Edge of Tibetan Plateau.

As a versatile cruciferous species, Eruca sativa is widely cultivated, but in some areas, it has become an invasive weed. There are few studies on its seed dormancy and soil seed bank. This research examined seed dormancy, germination, and dynamics of the soil seed bank of E. sativa, with a view to provide support for its prevention and control. We tested the effects of temperature, light, storage, water, and salinity stress on seed germination and burial depth on seedling emergence of E. sativa. Dynamics of the soil seed bank were determined with a 24 month in situ seed-burial study. Seeds of E. sativa can germinate in a temperature range of 5–35°C; moreover, they exhibited non-deep physiological dormancy (NDPD) at maturity, which can be broken by dry storage or exposure to low temperature in winter. Germination of E. sativa seeds was sensitive to water and salinity stress, and most seeds did not germinate at -0.3 MPa. When buried in soil in the field, seeds exhibited an annual dormancy/non-dormancy cycle and formed at least a short-term persistent soil seed bank. Seeds buried deeper than 5 cm can hardly emerge. Seeds of E. sativa have a wide germination temperature range and exhibited dormancy cycling, which promotes the formation of a persistent soil seed bank and enables it to better adapt to the harsh low-temperature climate of the Qinghai-Tibet Plateau. No-tillage would be a good management strategy for this species.

Finite-element analysis of the hot-pressing consolidation of continuous Al2O3 fibers-reinforced NiAl composites

Abstract The finite-element method was used to model the consolidation process of continuous Al2O3 fiber-reinforced NiAl composites. Actual creep behavior of NiAl was accounted for including the instantaneous strain and primary creep behavior. Primary creep played a very important role in the consolidation process at high temperatures and high pressures. Various processing parameters were investigated to evaluate the effects of temperature and hot-pressing stress on the consolidation behavior. It was found that the effect of pressure on consolidation was more significant at high temperatures due to its strong influence on the creep rate during power-law creep. The effects of fiber volume fraction and the arrangement of the matrix-coated fibers were also analysed. The simulations recommend an optimal fiber volume fraction in the range of 30 %–50 %. Fully dense composites were fabricated according to the predicted processing conditions, and good agreement between simulation and experiment was achieved.

Effect of Short-term Elevation Temperature and Salinity Stress on Caspian Roach, Rutilus caspicus

Effect of Short-term Elevation Temperature and Salinity Stress on Caspian Roach, Rutilus caspicus

Effects of Low Temperature Stress on Source-Sink Organs in Wheat and Phosphorus Mitigation Strategies.

The 21st century presents many challenges to mankind, including climate change, fast growing human population, and serious concerns over food security. Wheat is a leading cereal crop that largely fulfills the global food needs. Low temperature stress accompanied by nutrient-starved soils is badly disrupting the source–sink relationship of wheat, thus causing an acute decline in final yield and deteriorating the grain quality. This review paper aimed to understand how low temperature stress affects wheat source–sink organs (i.e., leaves, roots, and spikes) and how phosphorus application reliefs in alleviating its harmful consequences. Also, we discussed mitigation strategies to enhance wheat capacity to adapt to varying temperature extremes and made rational recommendations based on modern agronomic and breeding approaches. Therefore, this study is likely to establish a solid foundation for improving the tolerance to low temperature stress and to improve its phosphorus utilization efficiency in wheat.

Hygrothermoelastic response of a finite hollow circular cylinder

In this paper, a hollow circular cylinder of finite length with finite extent occupying the space is considered. Based on the hygrothermoelasticity theory, the transient response of a hollow circular cylinder subjected to the hygrothermal loading at the surface is analyzed. The analytical solution for the coupling and uncoupling effects of temperature, moisture, and thermal stresses is obtained by using the integral transform technique. The numerical results of the transient response of the hygrothermoelasticity field are presented graphically for a graphite fiber–reinforced epoxy matrix composite material (T300/5208).