scholarly journals Spider Mites Singly Infected With Either Wolbachia or Spiroplasma Have Reduced Thermal Tolerance

2021 ◽  
Vol 12 ◽  
Author(s):  
Yu-Xi Zhu ◽  
Zhang-Rong Song ◽  
Yi-Yin Zhang ◽  
Ary A. Hoffmann ◽  
Xiao-Yue Hong
Keyword(s):  
High Temperature ◽  
Thermal Tolerance ◽  
Spider Mite ◽  
Heat Exposure ◽  
Dependent Manner ◽  
Bacterial Replication ◽  
Lower Temperature ◽  
Temperature Exposure ◽  
Temperature Impacts ◽  
The Impact

Heritable symbionts play an essential role in many aspects of host ecology in a temperature-dependent manner. However, how temperature impacts the host and their interaction with endosymbionts remains largely unknown. Here, we investigated the impact of moderate (20°C) and high (30 and 35°C) temperatures on symbioses between the spider mite Tetranychus truncatus and two maternally inherited endosymbionts (Wolbachia and Spiroplasma). We found that the thermal tolerance of mites (as measured by survival after heat exposure) was lower for mites that were singly infected with either Wolbachia or Spiroplasma than it was for co-infected or uninfected mites. Although a relatively high temperature (30°C) is thought to promote bacterial replication, rearing at high temperature (35°C) resulted in losses of Wolbachia and particularly Spiroplasma. Exposing the mites to 20°C reduced the density and transmission of Spiroplasma but not Wolbachia. The four spider mite strains tested differed in the numbers of heat shock genes (Hsps) induced under moderate or high temperature exposure. In thermal preference (Tp) assays, the two Wolbachia-infected spider mite strains preferred a lower temperature than strains without Wolbachia. Our results show that endosymbiont-mediated spider mite responses to temperature stress are complex, involving a combination of changing endosymbiont infection patterns, altered thermoregulatory behavior, and transcription responses.

Long Term Degradation Behavior of Impact Properties of Hydraulic Forged Superalloy 718 during Exposure at High Temperature

2007 ◽  
Vol 26-28 ◽  
pp. 1071-1074
Author(s):  
Young Seok Song ◽  
M.R. Lee ◽  
Jeong Tae Kim
Keyword(s):  
High Temperature ◽  
Impact Energy ◽  
Melting Process ◽  
Hydraulic Press ◽  
Degradation Behavior ◽  
Impact Properties ◽  
Hardness Tests ◽  
Temperature Exposure ◽  
The Impact

To check long term degradation behavior of hydraulic forged superalloy 718 during exposure at high temperature, an Alloy 718 ingot with a diameter of 400mm was manufactured by the vacuum melting process, VIM followed by VAR. The ingot was broken down for uniform microstructure and mechanical properties by a controlled cogging process using a hydraulic press. To investigate long term degradation behavior of impact properties and hardness, the specimens were exposed to 600oC, 650oC and 700oC for holding times up to 12,112 hours. Impact energy absorption tests were performed at room temperature. The fractured area and the microstructure of the impact specimens were observed by OEM and SEM and Brinell hardness tests were also performed. The changes of impact energy and hardness are remarkably different for each temperature condition. The results suggest that the impact properties and hardness of Ni based superalloy 718 is strongly related to temperature and time during high temperature exposure.

scholarly journals The Influence of High Temperature Exposure on the Wear of Selected HVOF Sprayed Coatings

2016 ◽  
Vol 368 ◽  
pp. 55-58 ◽  
Author(s):  
Šárka Houdková ◽  
Eva Smazalová
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Adhesive Wear ◽  
Heat Exposure ◽  
Cohesive Strength ◽  
Wear Properties ◽  
High Temperature Exposure ◽  
Stellite 6 ◽  
Temperature Exposure ◽  
Sprayed Coatings

The influence of high temperature exposure on the mechanical and wear properties of selected HVOF sprayed CrC and No/Co – based alloy coatings were tested. Comparison of as-sprayed and 600°C/116 h annealed coatings’ microhardness, cohesive strength, abrasive and adhesive wear resistance showed that the Co-based Stellite 6 coating’s wear properties were deteriorated by heat exlosure despite of the increase of its hardness and cohesive strength. The heat exposure was found to be beneficial for both mechanical and wear properties of NiCrBSi self-fluxing coating. On the contrary, mechanical properties of Cr3C2-NiCr coating slightly decreased, while its wear resistance slightly increased as a result of high temperature exposure.

scholarly journals Microbiological evaluation of the impact of high temperature exposure on activity of antimicrobial drugs.

2019 ◽  
Vol 199 (1) ◽  
pp. 27-31
Author(s):  
B.Ye. Tuleubaev ◽  
◽  
D.A. Saginova ◽  
E.R. Tashmetov ◽  
A.A. Koshanova ◽  
...  
Keyword(s):  
High Temperature ◽  
Antimicrobial Drugs ◽  
High Temperature Exposure ◽  
Temperature Exposure ◽  
The Impact

Intersplat Oxidation of Atmospheric Plasma Sprayed MCrAlY Coatings

2014 ◽  
Author(s):  
Robert Eriksson ◽  
Kang Yuan ◽  
Sten Johansson ◽  
Ru Lin Peng
Keyword(s):  
High Temperature ◽  
Gas Turbines ◽  
Surface Oxidation ◽  
Atmospheric Plasma ◽  
Mcraly Coatings ◽  
Surface Oxides ◽  
Structural Parts ◽  
Lower Temperature ◽  
Temperature Exposure ◽  
Plasma Sprayed

MCrAlY coatings and thermal barrier coatings (TBC) are commonly used in gas turbines to prolong the life of structural parts. The atmospheric plasma spray (APS) process yields coatings with a typical splat-on-splat structure which oxidizes at intersplat boundaries during high-temperature exposure. A study was performed to establish the influence of intersplat oxidation on Al depletion. It was found that the β-depletion based life may be overestimated by a factor of 1.8–18 if intersplat oxidation is not considered. Two different mechanisms of intersplat oxidation were observed: At high temperature (1050 °C), a fraction of the intersplat boundaries remained in contact with the coating surface and oxidized with the same kinetics as the surface oxides. At lower temperature (900 °C), intersplat oxidation occurred by considerable slower growth rates than surface oxidation. The mechanisms behind intersplat oxide growth was further studied by O diffusion calculations.

scholarly journals Effects of Accumulated And Transient Heat Exposure On Schizophrenia Hospitalizations: A Time-Series Analysis On Hourly Temperature Basis

2021 ◽  
Author(s):  
Chao Tang ◽  
Yifu Ji ◽  
Qingru Li ◽  
Zhenhai Yao ◽  
Jian Cheng ◽  
...  
Keyword(s):  
Heat Exposure ◽  
Warm Season ◽  
Negative Effects ◽  
Distributed Lag ◽  
Hourly Temperature ◽  
Health Significance ◽  
Temperature Exposure ◽  
Exposure Indicators ◽  
The Impact ◽  
Time Point

Abstract Background: Growing studies have shown that high temperature is a potential risk factor of schizophrenia occurrence. Therefore, elaborate analysis of different temperature exposure patterns such as cumulative heat exposure within a time period and transient exposure at a particular time point, is of important public health significance. This study aims to utilize hourly temperature data to better capture the effects of cumulative and transient heat exposures on schizophrenia during the warm season in Hefei, China. Methods: We included the daily mean temperature and daily schizophrenia hospitalizations into the distributed lag non-linear model (DLNM) to simulate the exposure-response curve and determine the heat threshold (19.4℃). We calculated and applied a novel indictor–daily excess heat hourly (DEHH) to examine the effects of cumulative heat exposure over a day on schizophrenia hospitalizations. Temperature measurements at each time point were also incorporated in the DLNM as independent exposure indicators to analyze the impact of transient heat exposure on schizophrenia. Results: Each increment of interquartile range (IQR) in DEHH was associated with elevated risk of schizophrenia hospitalizations from lag 1 (RR=1.036, 95% confidence interval (CI): 1.016, 1.057) to lag 4 (RR=1.025, 95% CI: 1.005, 1.046). Men and people over 40 years old were more susceptible to DEHH. Besides, we found a greater risk of heat-related schizophrenia hospitalizations between 0 am and 6 am.Conclusions: This study revealed the negative effects of accumulated and transient heat exposures on schizophrenia hospitalizations. Our findings need to be further tested in other regions with distinct regional features.

scholarly journals Plastic responses of survival and fertility following heat stress in pupal and adult Drosophila virilis

2021 ◽  
Author(s):  
Benjamin Walsh ◽  
Steven Parratt ◽  
Natasha Mannion ◽  
Rhonda Snook ◽  
Amanda Bretman ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
High Temperatures ◽  
Male Fertility ◽  
Thermal Tolerance ◽  
Drosophila Virilis ◽  
Life History Stage ◽  
Heat Hardening ◽  
The Impact

The impact of rising global temperatures on survival and reproduction is putting many species at risk of extinction. In particular, it has recently been shown that thermal effects on reproduction, especially limits to male fertility, can underpin species distributions in insects. However, the physiological factors influencing fertility at high temperatures are poorly understood. Key factors that affect somatic thermal tolerance such as hardening, the ability to phenotypically increase thermal tolerance after a mild heat shock, and the differential impact of temperature on different life stages, are largely unexplored for thermal fertility tolerance. Here, we examine the impact of high temperatures on male fertility in the cosmopolitan fruit fly Drosophila virilis. We first determined whether temperature stress at either the pupal or adult life-history stage impacts fertility. We then tested the capacity for heat-hardening to mitigate heat-induced sterility. We found that thermal stress reduces fertility in different ways in pupae and adults. Pupal heat stress delays sexual maturity, whereas males heated as adults can reproduce initially following heat stress, but lose the ability to produce offspring. We also found evidence that while heat-hardening in D. virilis can improve high temperature survival, there is no significant protective impact of this same hardening treatment on fertility. These results suggest that males may be unable to prevent the costs of high temperature stress on fertility through heat-hardening which limits a species’ ability to quickly and effectively reduce fertility loss in the face of short-term high temperature events.

scholarly journals Experimental warming reduces gut prokaryotic diversity, survival and thermal tolerance of the eastern subterranean termite, Reticulitermes flavipes (Kollar)

2020 ◽  
Author(s):  
Rachel A. Arango ◽  
Sean D. Schoville ◽  
Cameron R. Currie ◽  
Camila Carlos-Shanley
Keyword(s):  
High Temperature ◽  
Environmental Changes ◽  
Reticulitermes Flavipes ◽  
Bacterial Symbionts ◽  
Integral Role ◽  
Potential Link ◽  
Microbial Symbionts ◽  
Temperature Exposure ◽  
Eastern Subterranean Termite ◽  
The Impact

AbstractUnderstanding the effects of environmental disturbances on the health and physiology of insects is crucial in predicting the impact of climate change on their distribution, abundance, and ecology. As microbial symbionts have been shown to play an integral role in a diversity of functions within the insect host, research examining how organisms adapt to environmental fluctuations should include their associated microbiota. Previous studies have shown that temperature affects the diversity of protists in termite gut, but less is known about the bacterial symbionts. In this study, subterranean termites (Reticulitermes flavipes (Kollar)) were exposed to three different temperature treatments characterized as low (15 °C), medium (27 °C), and high (35 °C). Results showed low temperature exposed termites had significantly lower CTmin and significantly higher SCP values compared to termites from medium or high temperature groups. This suggests that pre-exposure to cold allowed termites to stay active longer in decreasing temperatures but caused termites to freeze at higher temperatures. High temperature exposure had the most deleterious effects on termites with a significant reduction in termite survival as well as reduced ability to withstand cold stress. The microbial community of high temperature exposed termites showed a reduction in bacterial richness and decreased relative abundance of Spirochaetes, Elusimicrobia, and methanogenic Euryarchaeota. Our results indicate a potential link between gut bacterial symbionts and termite’s physiological response to environmental changes and highlight the need to consider microbial symbionts in studies relating to insect thermosensitivity.

scholarly journals Perceptions of workplace heat exposure and adaption behaviors among Chinese construction workers in the context of climate change

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shu-Rong Han ◽  
Mingru Wei ◽  
Zhifeng Wu ◽  
Shanshan Duan ◽  
Xiangzhe Chen ◽  
...  
Keyword(s):  
Climate Change ◽  
High Temperature ◽  
High Temperatures ◽  
Heat Exposure ◽  
Construction Workers ◽  
Work Efficiency ◽  
Snowball Sampling ◽  
Online Questionnaire ◽  
Cross Sectional ◽  
The Impact

Abstract Background Workplace heat exposure can cause a series of heat-related illnesses and injuries. Protecting workers especially those undertake work outdoors from the risk of heat strain is a great challenge for many workplaces in China under the context of climate change. The aim of this study is to investigate the perceptions and adaptation behaviors of heat exposure among construction workers and to provide evidence for the development of targeted heat adaptation strategies nationally and internationally. Methods In 2020, we conducted a cross-sectional online questionnaire survey via WeChat Survey Star in China, using a purposive snowball sampling approach. A total of 326 construction workers submitted completed questionnaires. The perceptions of workplace heat exposure were measured using seven indicators: concerns over high temperature, perception of high temperature injury, attitudes towards both heat-related training and regulations, adjustment of working habits during heat, heat prevention measures in the workplace, and reduction of work efficiency. Bivariate and multivariate regression analyses were used to identify the factors significantly associated with workers’ heat perceptions and behavioral responses. Results 33.3% of the respondents were moderately or very concerned about heat exposure in the workplace. Less than half of the workers (43.8%) were worried about heat-related injuries. Workers who have either experienced work-related injuries (OR = 1.30, 95% CI 1.03–1.62) or witnessed injuries to others during high temperatures (OR = 1.12, 95% CI 1.02–1.27) were more concerned about heat exposure compared to other workers. Most respondents (63.5%) stated that their work efficiency declined during extremely hot weather. The factors significantly associated with a reduction of work efficiency included undertaking physically demanding jobs (OR = 1.28, 95% CI 1.07–1.54) and witnessing other workers’ injuries during high temperatures (OR = 1.26, 95% CI 1.11–1.43). More than half of the workers were willing to adjust their work habits to adapt to the impact of high temperatures (81.6%). The internet was the most common method to obtain heat prevention information (44.7%), and the most frequently used heat prevention measure was the provision of cool drinking water (64.8%). Conclusions Chinese construction workers lack heat risk awareness and are not well prepared for the likely increasing heat exposure in the workplace due to global warming. Therefore, there is a need to improve their awareness of heat-related injuries, strengthen high temperature related education and training, and update the current heat prevention policies to ensure compliance and implementation.

scholarly journals Post-conception heat exposure increases clinically unobserved pregnancy losses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tamás Hajdu ◽  
Gábor Hajdu
Keyword(s):  
Early Pregnancy ◽  
Human Embryo ◽  
Pregnancy Loss ◽  
Loss Rate ◽  
Heat Exposure ◽  
Compositional Change ◽  
Temperature Exposure ◽  
Induced Changes ◽  
The Impact ◽  
The Relationship

AbstractEvidence of the relationship between temperature during pregnancy and human embryo mortality is limited. Most importantly, the literature lacks causal estimations and studies on early pregnancy losses. Here, we estimate the impact of early pregnancy temperature exposure on the clinically unobserved pregnancy loss rate. We use administrative data of clinically observed pregnancies from more than three decades for Hungary. We apply an empirical approach that allows us to infer the impact of temperature on the clinically unobserved pregnancy loss rate from the estimated effects on the clinically observed conception rate. The results show that exposure to hot temperatures during the first few weeks after the conception week increases the clinically unobserved pregnancy loss rate, whereas exposure to colder temperatures seems to decrease it. Importantly, the temperature-induced changes represent changes in the total number of pregnancy losses rather than a compositional change between clinically observed and clinically unobserved pregnancy losses.

scholarly journals Experimental Warming Reduces Survival, Cold Tolerance, and Gut Prokaryotic Diversity of the Eastern Subterranean Termite, Reticulitermes flavipes (Kollar)

2021 ◽  
Vol 12 ◽  
Author(s):  
Rachel A. Arango ◽  
Sean D. Schoville ◽  
Cameron R. Currie ◽  
Camila Carlos-Shanley
Keyword(s):  
High Temperature ◽  
Environmental Changes ◽  
Reticulitermes Flavipes ◽  
Prokaryotic Diversity ◽  
Integral Role ◽  
Potential Link ◽  
Microbial Symbionts ◽  
Temperature Exposure ◽  
Eastern Subterranean Termite ◽  
The Impact

Understanding the effects of environmental disturbances on insects is crucial in predicting the impact of climate change on their distribution, abundance, and ecology. As microbial symbionts are known to play an integral role in a diversity of functions within the insect host, research examining how organisms adapt to environmental fluctuations should include their associated microbiota. In this study, subterranean termites [Reticulitermes flavipes (Kollar)] were exposed to three different temperature treatments characterized as low (15°C), medium (27°C), and high (35°C). Results suggested that pre-exposure to cold allowed termites to stay active longer in decreasing temperatures but caused termites to freeze at higher temperatures. High temperature exposure had the most deleterious effects on termites with a significant reduction in termite survival as well as reduced ability to withstand cold stress. The microbial community of high temperature exposed termites also showed a reduction in bacterial richness and decreased relative abundance of Spirochaetes, Elusimicrobia, and methanogenic Euryarchaeota. Our results indicate a potential link between gut bacterial symbionts and termite’s physiological response to environmental changes and highlight the need to consider microbial symbionts in studies relating to insect thermosensitivity.

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