• 한국가금학회지
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• 제21권2호
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• pp.93-99
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• 1994

Chickens subjected to heat stress decrease their heat production by consuming less feed. The lowered feed intake naturally brings about decreased production performance of chicken. The only exception to this is the increased survivability. Birds drink less when they eat less. In hot enviror-mental temperature, chicken need more water for increased heat loss through evaporation an increased urine excretion. Thus, the increased water intake may alleviate the heat stress of chicken. Various electrolytes supplementation to feed or drinking water can alleviate the heat stress of chicken by their effect of increasing water intake. Lasalocid, an ionophorous coccidiostat, was found to have the effect of increasing water consumption of chicken, thereby improving the lowered production performance of heat-stressed chicken. Finally, dietary fiber could be another possible element which can exert beneficial effects on heat-stressed chicken.

• Journal of Welding and Joining
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• 제5권2호
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• pp.9-16
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• 1987

Post weld heat treatment (PWHT) is carried out to increase the fracture toughness in heat affected zone(HAZ) and remove the residual stress. There occur some problems such as toughness decreement and stress relief cracking(SRC) in the coarse grained HAZ subjected to the effect of tempering treatment. Especially, embitterment of structure directly relates to the mode of fracture and is appeared as the difference of fracture surface, that is, grain boundary failure. Therefore, in this paper, PWHT was carried out under the stress of 0, 10, 20 and $30kg/cm^2$ to simulate residual stress in HAZ welded by heat input of 10, 30 and 40KJ/cm. Applied stress in weld HAZ during PWHT assisted precipitin of over saturated alloying element in the structure, and grain boundary failure according to welding heat input didn't almost appear at the heat input of 10 KJ/cm, but it appeared from being the applied stress of $30kg/cm^2$ at $30KJ/cm and 20kg/mm^2$ at 40KJ/cm.

• 농업과학연구
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• 제46권3호
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• pp.637-643
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• 2019

The aim of the present study was to evaluate the effect of the induced heat stress on physiological response and serum biochemical parameters involving glucose, cholesterol, blood urea nitrogen (BUN), non-esterified fatty acids (NEFA), and cortisol in Holstein calves. Ten calves were kept in a climate controlled room (air temperature $37^{\circ}C$ and 90% humidity from 09:00 to 19:00) for three days. Those animals were given a one-day adaptation period. During the treatment period, we measured the skin temperature six times. Following the treatment periods, blood samples were collected before the experiment began (09:00) and at the end of the stress period (19:00). To aid analysis of the biochemical parameters, also we monitored the rectal temperature. The results, exhibited that both rectal and skin temperature showed increase in the heat stress-induced animals as compared with unstressed animals. Moreover, we noticed that the levels of BUN and NEFA increased in the blood serum of heat stress induced animals when compared with un-stressed ones. From these results, we concluded that the physiological and biochemical changes in the calves were induced by heat stress. Hence, the present study findings could be employed as base line data for development of stress reduction techniques in the dairy industry.

• Journal of Ginseng Research
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• 제43권4호
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• pp.572-579
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• 2019

Background: Panax ginseng has been used in traditional medicine to strengthen the body and mental well-being of humans for thousands of years. Many elite ginseng cultivars have been developed, and ginseng cultivation has become well established during the last century. However, heat stress poses an important threat to the growth and sustainable production of ginseng. Efforts have been made to study the effects of high temperature on ginseng physiology, but knowledge of the molecular responses to heat stress is still limited. Methods: We sequenced the transcriptomes (RNA-Seq) of two ginseng cultivars, Chunpoong (CP) and Yunpoong (YP), which are sensitive and resistant to heat stress, respectively, after 1- and 3-week heat treatments. Differential gene expression and gene ontology enrichment along with profiled chlorophyll contents were performed. Results: CP is more sensitive to heat stress than YP and exhibited a lower chlorophyll content than YP. Moreover, heat stress reduced the chlorophyll content more rapidly in CP than in YP. A total of 329 heat-responsive genes were identified. Intriguingly, genes encoding chlorophyll a/b-binding proteins, WRKY transcription factors, and fatty acid desaturase were predominantly responsive during heat stress and appeared to regulate photosynthesis. In addition, a genome-wide scan of photosynthetic and sugar metabolic genes revealed reduced transcription levels for ribulose 1,5-bisphosphate carboxylase/oxygenase under heat stress, especially in CP, possibly attributable to elevated levels of soluble sugars. Conclusion: Our comprehensive genomic analysis reveals candidate loci/gene targets for breeding and functional studies related to developing high temperature-tolerant ginseng varieties.

• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.403-409
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• 2010

Saccharomyces cerevisiae Hsp30 is a plasma membrane heat shock protein that is induced by various environmental stress conditions. However, the functional role of Hsp30 during diverse environmental stressors is not presently known. To gain insight into its function during thermal stress, we have constructed and characterized a ${\Delta}hsp30$ strain during heat stress. $BY4741{\Delta}hsp30$ cells were found to be more sensitive compared with BY4741 cells, when exposed to a lethal heat stress at $50^{\circ}C$. When budding yeast is exposed to either heat shock or weak organic acid, it inhibits Pma1p activity. In this study, we measured the levels of Pma1p in mutant and Wt cells both during optimal temperature and heat shock temperature. We observed that $BY4741{\Delta}hsp30$ cells showed constitutive reduction of Pma1p. To gain further insights into the role of Hsp30 during heat stress, we compared the total protein profile by 2D gel electrophoresis followed by identification of differentially expressed spots by LC-MS. We observed that contrary to that expected from thermal-stress-induced changes in gene expression, the ${\Delta}hsp30$ mutant maintained elevated levels of Pdc1p, Trx1p, and Nbp35p and reduced levels of Atp2p and Sod1p during heat shock. In conclusion, Hsp30 is necessary during lethal heat stress, for the maintenance of Pma1p and a set of thermal stress response functions.

• 한국동물생명공학회지
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• 제34권3호
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• pp.173-182
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• 2019

This study was performed to evaluate the effect of heat stress on the status of physiological responses, blood parameter, serum T3 and cortisol, and heat shock proteins (HSP 27, 70, and 90) of Hanwoo cattle. Six Hanwoo steers (242.8 ± 7.2 kg of BW) were housed in the climate-controlled respiration chambers. The experiment consisted of 7 days (control; 0 day) at thermoneutral (air temperature (Ta) of 15℃ and relative humidity (RH) of 60%; temperature-humidity index (THI) = 64), and by 3 and 6 days (treatment groups) at heat stress (Ta of 35℃ and RH of 60%; THI = 87). Body temperature of each parts (frank, rump, perineum and foot) and rectal temperature elevated in heat stress groups (3 days and 6 days) than the control group (0 day). Respiration rates increased in 3 days and 6 days (88.5 ± 0.96 bpm and 86.3 ± 0.63 bpm, respectively) from 0 days (39.5 ± 0.65 bpm). Feed intake significantly decreased in heat stress groups (3 days and 6 days, 3.7 ± 0.14 kg and 4.0 ± 0.15 kg, respectively) than the control group (0 day, 5.0 ± 0.00 kg). In addition, final BW significantly decreased in heat stress groups (3 days and 6 days, 211.8 ± 4.75 kg and 215.5 ± 3.50 kg, respectively) than the control group (0 day, 240.0 ± 25.00 kg). However, heat stress has no significant effect on blood parameter, serum T3 and cortisol. Nevertheless, heat stress increased HSPs mRNA expression in liver tissue, and serum concentration of HSPs. Despite Hanwoo cattle may have high adaptive ability to heat stress, our results suggested that heat stress directly effect on body temperature and respiration rate as well as serum and tissue HSPs. Therefore, we are recommended that HSPs could be the most appropriate indicators of Hanwoo cattle response to heat stress.

• Asian-Australasian Journal of Animal Sciences
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• 제13권10호
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• pp.1373-1376
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• 2000

The peroxidation status of tissues was estimated in broilers under acute or chronic heat stress ($32^{\circ}C$, 24 h, $5{\times}24h$) in the present study. The results showed that the lipid peroxide (LPO) concentrations in plasma and liver were elevated (p<0.05) by acute heat stress, and were not influenced in kidney (p>0.05). At the same time, no significant change of superoxide dismutase (SOD) activity in the liver, kidney or plasma was observed. Under chronic heat exposure, the SOD activity in liver was increased (p<0.05) and the LPO concentrations in the liver and plasma were restored to the normal levels. The LPO level in kidney was not affected by chronic heat stress (p>0.05), but SOD activity was significantly decreased (p<0.01). The results suggested that the peroxidation was induced by acute heat stress and disappeared along with the time of heat exposure, and the peroxidation reactions were different among tissues.

• Animal Bioscience
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• 제37권6호
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• pp.1121-1129
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• 2024

Objective: Objective of the study was to reduce heat stress in Murrah buffaloes and maintain their milk production and other vital functions during heat stress. Methods: A total of 21 dyads of calf-mother Murrah buffalo were selected for the study and equally divided in 3 treatment groups. First treatment group was restricted calf contact (RCC), second treatment group was fence line calf contact (FCC) and third treatment groups fence line calf contact and heat stress protection (FCC-HSP [time-controlled fan-fogger system] in the shed). Present study was conducted from April to mid-September 2021. Results: Maximum temperature and temperature humidity index in FCC-HSP shed were significantly (p<0.05) lower than that in FCC and RCC shed. Higher (p<0.05) mean daily milk yield in both the treatment groups FCC (10.36±0.30) and FCC-HSP (10.97±0.31) than RCC (8.29±0.41) was recorded. Though no significant difference between FCC and FCC-HSP in daily milk yield but FCC-HSP yielded 600 gm more milk than FCC. Pulse rate (PR) and respiration rate (RR) were lowest in FCC-HSP followed by FCC and RCC, respectively. Cortisol and prolactin levels were lower (p<0.05) in FCC-HSP followed by FCC and RCC, respectively. Conclusion: Hence, FCC along with heat stress ameliorative measures helped the buffaloes to be free of stress and maintain milk yield during heat stress period of the year in tropical conditions.

• 한국초지조사료학회지
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• 제33권3호
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• pp.159-166
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• 2013

We have previously investigated the proteome changes of rice leaves under heat stress (Lee et al. in Proteomics 2007a, 7:3369-3383), wherein a group of antioxidant proteins and heat shock proteins (HSPs) were found to be regulated differently. The present study focuses on the biochemical changes and gene expression profiles of heat shock protein and antioxidant genes in rice leaves in response to heat stress ($42^{\circ}C$) during a wide range of exposure times. The results show that hydrogen peroxide and proline contents increased significantly, suggesting an oxidative burst and osmotic imbalance under heat stress. The mRNA levels of chaperone 60, HSP70, HSP100, chloroplastic HSP26, and mitochondrial small HSP responded rapidly and showed maximum expression after 0.5 or 2 h under heat stress. Transcript levels of ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and Cu-Zn superoxide dismutase (Cu-Zn SOD) showed a rapid and marked accumulation upon heat stress. While prolonged exposure to heat stress resulted in increased transcript levels of monodehydroascorbate reductase, peroxidase, glyoxalase 1, glutathione reductase, thioredoxin peroxidase, 2-Cysteine peroxiredoxin, and nucleoside diphosphate kinase 1, while the transcription of catalase was suppressed. Consistent with their changes in gene expression, the enzyme activities of APX and DHAR also increased significantly following exposure to heat stress. These results suggest that oxidative stress is usually caused by heat stress, and plants apply complex HSP- and antioxidant-mediated defense mechanisms to cope with heat stress.

• Animal cells and systems
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• 제14권4호
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• pp.267-274
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• 2010

The decrease in sperm quality under heat stress causes a great loss in animal husbandry production. In order to reveal the mechanism underlying the sperm quality decrease caused by heat stress, we first established a mild heat-treated mouse model. Then, the sperm quality was identified. Further, the testicular proteome profile was mapped and compared with the control using 2D electrophoresis and mass spectrometry. Finally, the differential expressed proteins involved in the heat stress response were identified by real-time PCR and Western blotting. The results showed that heat stress caused a significant reduction in mouse sperm quality (P<0.05). Further, 52 protein spots on the 2D gel were found to differ between the heat-shocked tissues and the control. Of these spots, some repair proteins which might provide some explanation for the influence on sperm quality were found. We then focused on Bag-1, Hsp40, Hsp60 and Hsp70, which were found to be differently expressed after heat shock (P<0.05). Further analysis in this heat-shocked model suggests numerous potential mechanisms for heat shock-induced spermatogenic disorders.