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Temperature is a critical environmental factor influencing insect development, physiology, and distribution. Global warming is predicted to increase the frequency and severity of extreme heat events, influencing insects differently across life stages. This study investigates the effects of short- and long-term thermal stress on the tobacco cutworm, Spodoptera litura , a polyphagous pest damaging over 389 plant species. We exposed eggs, larvae, pupae, and adults to elevated temperatures of 42°C and 46°C for four hours and one hour, respectively, in single and repeated occasions for two, four, two and two days for egg, larva, pupa and adults, respectively. Our results demonstrate significant variation in biological and reproductive fitness parameters across treatments. Notably, thermal stress skewed the sex ratio towards females. We also observed impacts on offspring survival and potential negative carry-over effects. Overall, the effects of heat stress were dependent on temperature, exposure duration, and life stage, with adults exhibiting the highest tolerance. These findings suggest that S. litura possesses a degree of heat tolerance that may enable it to survive summer heat waves, but its offspring and other life stages could be more vulnerable under future climate scenarios. [ABSTRACT FROM AUTHOR]

ABSTRACT Temperature, an important abiotic factor, alters physiological processes in insects. This study includes effect of temperatures under laboratory (7°C, 12°C, 17°C, 22°C, 27°C and 32°C) and field (10°C–26°C) conditions on the life table parameters, total reactive oxygen species (ROS), hydrogen peroxide (H2O2), malondialdehyde (MDA) content and activities of antioxidative [superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX)], detoxifying [acetylcholinesterase (AChE), β‐glucosidase and glutathione‐S‐transferase (GST)] and oxidoreductive [peroxidase (POD) and polyphenol oxidase (PPO)] enzymes of Aphis craccivora Koch and A. gossypii Glover (Hemiptera: Aphididae) on Lablab purpureus subsp. bengalensis (Jacq.) Verdc. plants. The longevity and fecundity of both aphids were highest at 22°C, and A. craccivora showed similarity between 22°C and field condition but A. gossypii showed similarity between 17°C and field condition, suggesting that A. craccivora is able to withstand more fluctuating temperature stress than A. gossypii. Total ROS, H2O2 and MDA content were increased at low (7°C) or high (32°C) temperature but these parameters were more increased at high temperature than low temperature, suggesting that high‐temperature stress is more harmful for both aphids. Under low (7°C) or high (32°C) temperature stress, the levels of antioxidative, detoxifying and oxidoreductive enzymes were increased in both adult aphids compared to 22°C or field condition, implicating that both these aphids are trying to detoxify excess ROS by producing more antioxidative, detoxifying and oxidoreductive enzymes. The mortality of both aphids was higher at low (7°C) and high (32°C) temperatures, implicating that both aphids could not detoxify excess ROS by the coordinated action of antioxidative, detoxifying and oxidoreductive enzymes. The findings of this study can assist to envisage the population dynamics of these two important aphids, which can assist in management of these two sucking insect pests in the crop field. [ABSTRACT FROM AUTHOR]

Azo-containing liquid crystal elastomers are photomechanical materials that can be actuated via illumination. The photomechanical response is a result of the photoisomerization of the azo moiety, which produces bulk stresses in the material. These stresses arise via two distinct and competing mechanisms: order parameter change induced stress and direct contractile stress. We describe thermomechanical and photomechanical experiments aimed at assessing the relative contributions of these. We show that the details of the attachment of azo dyes to the network can greatly influence the photoresponse. We discuss our results and summarize our findings. [ABSTRACT FROM AUTHOR]

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North Carolina (NC) is in a biogeographic transition zone where climate change is altering the relative abundances (e.g., areal extent, percent cover, biomass) of Zostera marina and Halodule wrightii. Warmer water temperatures are driving losses in Z. marina, leading to increased meadow patchiness. Although water temperatures are rising in NC, heat-tolerant H. wrightii is not filling in bare patches, which may result from abiotic stressors. This study investigated H. wrightii cold tolerance across different populations by quantifying the effects of cold stress on biomass and photosynthetic efficiency during a 3-week laboratory experiment and a 3-month observational study. H. wrightii shoots for the experiment were collected from NC, Mississippi (MS), and Florida (FL) and exposed to 23 °C, 10 °C, and 5 °C. Seagrass was also collected from FL, MS, and at 3 sites in NC during November–January of 2022–2023. Post experiment, there was a significant increase in the belowground biomass in the NC 10 °C treatment but no difference between populations in photosynthetic efficiency. Field metrics displayed population-specific differences, with the northernmost sites having the highest shoot density and belowground biomass per unit area. These findings suggest that H. wrightii at its biogeographic limit may allocate more carbon into belowground material than populations at the central part of the species range in response to thermal stress as a means of winter torpor, which may explain the lack of patch expansion in NC. Cold tolerance in tropical species like H. wrightii may therefore be essential to examine as a limiting factor for the tropicalization of temperate seagrass meadows. [ABSTRACT FROM AUTHOR]

Due to reduced rear‐side ventilation, building‐integrated photovoltaics (BIPV) are prone to higher operating temperatures, which may impact their long‐term performance and reliability. However, often overlooked in the study of thermomechanical stress in PV modules are the intraday temperature variations, resulting from factors such as cloud movements and subsequent changes in irradiance. This work proposes a statistical analysis of cell and module temperature measurements in single‐cell c‐Si modules on a test bench in Neuchâtel, Switzerland. The goal is to study and compare various BIPV‐relevant module topologies with a range of factors such as the insulation type, tilt angle, and glass thickness. The standard indicators such as the 98th percentile temperature and diurnal temperature variations are examined, as well as proposed new thermomechanical stress indicators based on temperature gradients and cell versus module temperature differences. Unexpectedly, results indicate that, considering the intraday temperature variations, close‐roof module configurations (with small ventilation gaps) are potentially at a higher risk of suffering long‐term thermomechanical fatigue than fully insulated modules, which are exposed to higher operating temperatures. [ABSTRACT FROM AUTHOR]

Insects encounter variable temperature conditions in their natural habitats. Under non‐optimal temperatures, they experience thermal stress and oxidative damage, which are mitigated by antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT) and lipid peroxidation (LPO). While short‐term effects of thermal stress on antioxidant enzyme activities in insects are well understood, the long‐term effects are less explored. We investigated both short‐term (3 and 6 h) and long‐term (24 h) effects of thermal stress on SOD, CAT and LPO activities in the Parthenium beetle, Zygogramma bicolorata Pallister at cold (15°C), control/optimal (25°C) and hot (35°C) temperatures. Although Z. bicolorata is an effective biocontrol agent for noxious Parthenium weed, no prior study assessed the impact of thermal stress on antioxidant enzyme activities in this beetle. Our results revealed that antioxidant enzymes activities increased above control levels in both larvae and adults when exposed to thermal stress for short durations. Under long‐term thermal stress, CAT and LPO activities decreased below control levels, while SOD activity increased. Regardless of temperature conditions, early larval instars exhibited higher enzyme activities compared to later instars. In adults, males showed higher SOD and CAT activities, whereas LPO activity did not differ significantly between sexes. Our findings suggest that short‐term thermal stress can stimulate protective enzyme activity in these beetles and help them adapt to suboptimal temperatures. However, prolonged exposure may lead to excessive stimulation, potentially inhibiting protective enzyme activity and causing the beetles to activate alternative pathways to manage thermal stress. Moreover, fourth instars and adult females are the most thermal stress‐tolerant stages for Parthenium biocontrol. [ABSTRACT FROM AUTHOR]

Coral bleaching events have become more frequent in recent years due to the impact of widespread marine heatwaves. The Coral Reef Watch (CRW) program, part of the National Oceanic and Atmospheric Administration (NOAA), assesses bleaching risk by considering measures of daily coral heat stress (Hotspot, HS) and accumulated heat stress (Degree Heating Week, DHW). However, there is a mismatch between coral bleaching alerts through satellite monitoring and records of coral bleaching in the South China Sea (SCS) and its surrounding seas in the historical database. Through comparison with field records of bleaching events in the SCS, this study examined the optimization of the DHW under a fixed or variable HS threshold, evaluating the accuracy of coral bleaching monitoring through a range of evaluation indices, including the Peirce Skill Score (PSS) and the Area Under the Curve (AUC). Our results show that when the DHW index was calculated based on the current operational HS threshold (1°C), reducing the DHW threshold from 4°C to 1.86°C-weeks significantly improved PSS from 0.17 to 0.66, and AUC from 0.58 to 0.83. Further, by optimizing both HS and DHW, evaluation statistics were further improved, with the PSS increasing to 0.71 and the AUC increasing to 0.85. While both methods could significantly optimize the operational bleaching alert level for the SCS, the results suggest that optimization of both the HS and DHW thresholds is better than optimizing DHW alone. As marine heatwaves become more frequent, accurately predicting when and where coral bleaching is likely to occur will be critical to improving the estimation of regional coral stress due to climate change and for understanding coral reefs' response to recurrent bleaching events. [ABSTRACT FROM AUTHOR]

With the intensification of global climate change, extreme weather events are becoming more frequent, and the thermodynamic performance and fatigue life of high-voltage transmission lines in high-temperature and high-humidity environments are increasingly drawing attention. High-temperature and high-humidity conditions have a complex impact on the thermal stress and material fatigue of transmission lines, potentially reducing the reliability and service life of the power grid. To address this issue, this paper proposes a thermodynamic analysis-based model for calculating thermal stress and predicting fatigue life of high-voltage transmission lines under high-temperature and high-humidity conditions. The study first provides a detailed analysis of the thermal stress in transmission lines under high-temperature and high-humidity conditions, revealing the impact of temperature and humidity variations on the thermal expansion and deformation of the lines. Subsequently, combining material fatigue theory, the paper establishes a fatigue life prediction model for the lines, quantifying the accumulation process of fatigue damage under the influence of thermal stress. Through this theoretical model, the paper aims to provide a scientific basis for the design, evaluation, and maintenance of high-voltage transmission lines in harsh environments, ensuring the stability and safety of the power system. [ABSTRACT FROM AUTHOR]

Background: Heat stress is one of the main causes of mortality and reduced productivity in poultry. The current study aims to control heat stress of chickens by incorporating the seed of G. simplicifolia in their feed. Methods: This study was carried out in a poultry farm located at Badja (Togo) for three months on 210-day-old chicks of Sasso strain, divided into five groups. The birds of groups T0, T2, T3 and T4 received G. Simplicifolia seed in their feed at doses of 0.0; 2.5; 5.0 and 10.0 g/kg of feed respectively. The chickens of group T0 served as negative control group. Chickens of group T1 were fed 0.5 g of aspirin/kg of feed, served as a positive control group. Result: The result showed that the supplementation of G. simplicifolia seed in the feed improved the zootechnical and physiological parameters of the Sasso broilers. The presence of 5-HTP, fats, phenolic compounds and carotenoids in the seed improved the bird performances. In conclusion, G. simplicifolia seed can be used as an alternative to reduce heat stress of chickens in tropical regions. [ABSTRACT FROM AUTHOR]

In view of the absorption and diffusion characteristics of laser in the paint layer and the base layer, heat transfer model I and thermal connection boundary conditions for the paint layer and the metal base layer was established. As a comparison, corresponding heat transfer models II and III were established, with the thermal connection conditions at the interface between the paint layer and the base layer ignored. In model III, both the paint layer and the base layer were connected to the bulk heat source. A semi-analytical solution to the problem was obtained through the Laplacian transformation. Corresponding numerical solution examples were given through the Laplacian numerical inverse transformation. The results show that, model I gives continuous temperature distributions, while model II and model III give discontinuous temperature distributions, which goes against physical reality. Secondly, based on model I, the predicted time and energy density for cleaning and removing the paint layer are between those of model II and model III. The work provides a theoretical reference for improving the laser cleaning process. [ABSTRACT FROM AUTHOR]

This research aims to evaluate the physiological variables of native sheep raised in a controlled environment with different temperatures. Twenty-four entire male sheep of the Santa Inês (SI), Morada Nova (MN), no defined racial pattern (NDRP) and Soinga (SO) breeds were used. Rectal temperature (RT), respiratory rate (RR), heart rate (HR) and surface temperature (ST) were collected twice a day, during the last 5 days of each experimental phase. The HR (P = 0.001) showed a significant effect for the breed and temperature interaction. RT (P = 0.002) and HR (P < 0001) showed a significant effect of breed, where RT presented the highest value in the SI and NDRP breeds and similar to the SO, the MN presented the lowest value for RT. The RT, RR, HR, ST and SKT showed a significant effect (P < 0.0001) in relation to temperature. The STRT and SKTRT thermal gradients showed a significant difference (P < 0.0001) as a function of temperature. The groups were similar in terms of adaptation, even MN presenting low values for RT and HR, which changed abruptly considering the temperatures evaluated and from 28°C onwards the physiological variables are altered. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effects of arginine/lysine ratio (Arg/Lys) on the productive and reproductive performance, egg quality, immune and physiological parameters of hens reared under cyclic heat stress condition (CHS). A total of 140 females, and 20 males of 32 weeks of age, were randomly assigned to 4 treatment groups. The first group (positive control, PC) fed the basal corn-soybean meal diet with an Arg/Lys ratio of 1.25 and was kept at 22–24°C and 45–55% relative humidity. The other 3 treatments fed basal diet in which the Arg/Lys was set at 1.25, 1.37 and 1.50, respectively and were submitted to cyclic heat stress conditions (CHS, 38 °C ± 1, 55–65% RH) for three successive days a week from 10:00 am until 14:00. The results showed a reduction h-day egg production (EP), feed conversion ratio (FCR), shell weight, fertility and hatchability, hemoglobulin (Hgb), hydrogen power (pH) and plasma calcium and phosphorus concentrations for the negative control (NC) group compared to the positive control group. However, changing Arginine (Arg)/lysine (Lys) ratio in the basal diets for the groups under CHS from 1.25 to 1.37 and 1.50 improved EP, egg weight, egg mass and FCR when compared to NC group. Total lipid, total cholesterol, low-density lipoprotein, triglycerides, and malondialdehyde activity for the NC group significantly increased, while increasing the ratio of Arg/Lys to 1.37 and 1.50 improved the mentioned traits as to PC group. Our findings indicated that diets with an Arg/Lys ratio of 1.37 administered to laying hens farmed under cyclic heat stress conditions, are able to improve the laying performance, egg quality, fertility, hatchability, blood hematological and biochemical constituents, antioxidants, and immunity indices in comparison to the other groups, including the PC one. Thus, diets with an Arg/Lys ratio of 1.37 can be used to recover the adverse effect of CHS. HIGHLIGHTS: The diets with an Arg/Lys of 1.37 can be administered to laying hens to recover the adverse effect of cyclic heat stress. The arginine to lysine ratio can improve egg quality, fertility, hatchability, blood hematological and biochemical. [ABSTRACT FROM AUTHOR]

The present study was undertaken to determine the effect of heat stress on milk production (test day milk yield) and compositional traits (fat%, protein%, fat yield, protein yield) as well as to observe the pattern of response to increasing heat load on these traits in Jersey crossbred cows, maintained at ICAR-National Dairy Research Institute, Eastern Regional Station, Kalyani, West Bengal, India. The weather information, obtained from the NASA POWER database based on the location of the farm latitude and longitude, was used to calculate the Temperature Humidity Index (THI). To analyze the data, a linear model was fitted to the milk production and compositional records, which were adjusted for additive genetic effect of animal, permanent environmental effect of animals and known environmental sources of variations. Subsequently, a segmented linear regression model was fitted, and the least squares estimates of production and composition traits in different classes of THI were used as the dependent variable. Two THI break-points (BP) for milk yield and one THI BP for fat yield, protein %, and protein yield were found. The first and second BP for milk yield was at THI 59 and 77, respectively, with a significant decline in milk yield of -0.04 kg/unit of THI at second BP. The BP for fat and protein yield was at THI 76, with a decline rate of -1.18 and − 0.61 g/unit of THI increase, respectively. The findings revealed the significant adverse effects of THI on milk production and composition traits in Jersey crossbred cattle. [ABSTRACT FROM AUTHOR]

The spotted sea bass (Lateolabrax maculatus), a eurythermal species, exhibits strong adaptability to temperature variations and presents an ideal model for studying heat stress-responsive mechanisms in fish. This study examined the liver transcriptome of spotted sea bass over a 24-h period following exposure to elevated temperatures, rising from 25 to 32 °C. The results revealed significant alterations in gene expression in response to this thermal stress. Specifically, we identified 1702, 1199, 3128, and 2636 differentially expressed genes at 3, 6, 12, and 24 h post-stress, respectively. Weighted Gene Co-expression Network Analysis (WGCNA) was used to identify specific gene modules responsive to heat stress, containing hub genes such as aco2, eci2, h6pd, suclg1, fgg, fga, fgb, f2, and apoba, which play central roles in the heat stress response. Enrichment analyses via KEGG and GSEA indicated that upregulated differentially expressed genes (DEGs) are predominantly involved in protein processing in the endoplasmic reticulum, while downregulated genes are primarily associated with the AGE-RAGE signaling pathways. Additionally, 272 genes exhibited differential alternative splicing, primarily through exon skipping, underscoring the complexity of transcriptomic adaptations. These findings provide deeper insights into the molecular responses to thermal stress and are crucial for advancing the breeding of heat-resistant strains of spotted sea bass. [ABSTRACT FROM AUTHOR]

The objective of this study was to identify the Hsp70s in Paracoccus marginatus and explore their roles in P. marginatus's resistance to temperature and insecticide stress. The full-length cDNA sequences of PmHsp70s were obtained by PCR cloning and sequencing. The physicochemical and structural characteristics of PmHsp70s were analyzed, and a phylogenetic tree was constructed. The gene expressions of PmHsp70s were detected using qRT-PCR to explore the impacts of temperature and insecticide stress on P. marginatus. A total of 12 PmHsp70s were identified and cloned. The amino acids encoded by PmHsp70s were found to contain highly conserved regions characteristic of the Hsp70 family. The subcellular localization results showed that the majority of PmHsp70s were located in the cytoplasm. A total of 13 unique conserved motifs were identified for the PmHsp70s, of which 9 were shared motifs. The phylogenetic tree showed that the 12 PmHsp70s could be clustered into five branches, with the closest evolutionary relationship observed with the Phenacoccus solenopsis. The expression of the majority of PmHsp70s was up-regulated in P. marginatus when subjected to heat stress, with the higher expression fold change observed for PmHsp70-9, PmHsp70-11, and PmHsp70-12. The expression of specific PmHsp70s was notably suppressed under cold stress, whereas the expression of others was markedly enhanced. Upon exposure to chlorfenapyr and lambda-cyhalothrin, the expressions of PmHsp70-11 and PmHsp70-12 were significantly up-regulated with the highest expression fold change, respectively. The results revealed the significance of specific PmHsp70s in the resistance of P. marginatus to temperature and insecticide stress. This study improved our understanding of the mechanisms underlying P. marginatus's adaptive responses to unfavorable environmental conditions. [ABSTRACT FROM AUTHOR]

Urban public space comfort is essential for improving quality of life, particularly as climate change affects outdoor thermal environments. This study utilizes ENVI-met, a 3D microclimate simulation tool, to assess thermal comfort concerning demographic factors such as age and gender. The findings indicate significant disparities in thermal stress vulnerability among demographic groups. On the hottest day of July 2023, at 10 a.m., children's PET values were approximately 2 °C higher than those of other groups. By 3 p.m., females experienced slightly higher upper-range thermal stress than males. Elderly individuals aged 80 exhibited a broad range of PET values, from 38.14 °C to 62.39 °C, with prevailing values above 56.9 °C, indicating greater vulnerability to extreme heat. Children aged 8 showed PET values ranging from 40.20 °C to 59.34 °C, with prevailing estimates between 54.2 °C and 55.7 °C. Minimum PET values for children were significantly higher than those for adults, suggesting a greater baseline level of thermal stress. Despite cooling effects in the evening, children remained exposed to more pronounced stress than elderly individuals, males, and females. The UTCI values recorded indicate a period of extreme heat stress for all demographic groups assessed. While individuals aged 35 may encounter considerable discomfort, the severity of the impact is notably more pronounced for both older adults and children. This study underscores the need for tailored management strategies and advocates for expanding ENVI-met's capabilities to enhance urban resilience and well-being amid rising temperatures. [ABSTRACT FROM AUTHOR]

This study aimed to explore the effects of heat stress and black sand acute exposure on the erythron profile, hematological and antioxidant parameters, as well as histological and histochemical indices. Catfish were subjected to black sand nanoparticles (6.4 g of nanoparticles black sand per kg of diet), thermal stress (32 °C), and a combined treatment involving both stressors over a period of 15 days. Catfish exposed to black sand nanoparticles and heat stress singly and/or in combination showed significantly lower red blood cells (RBCs) count, hemoglobin (Hb), platelets, white blood cells (WBCs) count, large lymphocytes, small lymphocytes, and monocytes. Antioxidant indices decreased in black sand NPs and heat stress combination compared to other groups. Notably, the combination of black sand nanoparticles and heat stress led to a substantial increase in the percentages of both RBCs alterations and nuclear abnormalities. Histological examinations of the liver revealed various features, including intracellular bleeding, cytoplasmic vacuolation, tissue deterioration, hepatocyte pyknotic nuclei, nuclear displacement, shrinkage, and accumulation of melanomacrophage cells. In conclusion, the study underscores that the effects of black sand nanoparticles on erythron profile, hematological and antioxidant parameters, as well as histological and histochemical indices, become more pronounced under elevated temperatures indicating the potential for synergistic effects between pollution and climate change. This holistic approach is crucial for developing more accurate forecasts of the complex interactions between environmental stressors and their implications for aquatic ecosystems. [ABSTRACT FROM AUTHOR]