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        검색결과 91

        2.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cadmium (Cd), a heavy metal found in the aquatic environment, accumulates in organisms through the food chain. In the study, we investigated the survival rates, measurement of body Cd levels, and expression analysis of the stress response genes (Heat shock protein 70: HSP70 and Heat shock protein 60: HSP60) and antioxidant enzyme Glutathione S-Transferases (GST) on benthic oligochaete worm Tubifex tubifex exposed three concentrations of Cd, to analyze the bioaccumulation and changes of stress gene expressions to exposure toxicity of the Cd-spiked sediment. Survival rates of T. tubifex exposed to the Cdspiked sediment were 93% at 0.4 mg kg-1 Cd, 96% at 1.87 mg kg-1 Cd, and 93% at 6.09 mg kg-1 Cd for 10 days. Cd concentration in the body of T. tubifex was higher than that in the sediment. After Cd exposures for 10 days, the body Cd levels were 18.4 mg kg-1, 13.06 mg kg-1, and 79.11 mg kg-1 at exposed three concentrations of Cd, respectively. Upregulation of HSP70 gene expression was observed at all concentrations of exposed Cd as a time-dependent manner, whereas transcriptional expression of the HSP60 gene increased as a timedependent manner in T. tubifex exposed to the relative high concentration (6.09 mg kg-1) of Cd. However, GST gene expression increased on day 1 at all concentrations after Cd exposures, and then downregulated until 10 days. These results indicate to ecotoxicological and molecular effects in benthic oligochaete worm T. tubifex to Cd-spiked sediment and provide the basic information for the utilization of environmental toxicity assessment using the T. tubifex as a aquatic pollution indicator species.
        4,000원
        3.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 사료내 비테인, 글라이신, 그리고 콜린의 혼합 첨가가 고온 스트레스 환경에서 노령 산란계의 생산성, 난품질, 면역 반응 및 혈액성상에 미치는 영향을 조사하고자 수행되었다. 총 336마리의 86주령 로만 갈색종 노령 산란계를 6처리 7반복, 반복당 8수씩 임의 배치하였다. 대조구는 모든 영양소 및 에너지 요구량을 충족하거나 초과하도록 배합하였다. 대조구를 제외한 사료 처리구는 0.2% 비테인, 0.62% 글라이신, 그리고 0.32% 콜린을 단독, 두 가지 혼합, 혹은 세 가지 혼합으로 사료내 첨가하였다. 실험은 8주 동안 진행되었으며, 모든 산란계는 매일 8시간 동안 평균 온도 31.7±1.7℃, 습도 57%의 고온 스트레스 조건에서 사양되었고, 이외 시간에는 평균 온도 27±1.3℃, 습도 57%에서 사양하였다. 실험 결과, 비테인, 글라이신 및 콜린의 첨가는 생산성, 난품질, 그리고 면역 반응에 유의적인 영향을 미치지 않았다. 그러나, 0.2% 비테인과 0.62% 글라이신을 혼합 첨가한 처리구에서 혈청 알라닌 아미노전이효소 농도가 유의적으로 감소했다. 하지만, 다른 혈청 지표들은 처리간 유의적인 차이가 관찰되지 않았다. 결론적으로, 현재 수준에서 사료내 비테인, 글라이신, 그리고 콜린의 혼합 첨가는 고온 스트레스 환경에서 사양되는 노령 산란계의 생산성, 난품질, 면역 반응 및 혈액 성상에 긍정적인 영향을 미치지 않는다고 판단된다.
        4,000원
        4.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of the present experiment was to investigate the effects of dietary vitamin C (VC), vitamin E (VE), and betaine (BT) supplementations on productive performance, egg quality, relative organ weights, liver visual characteristics, antioxidant status, immune response, and stress indicator in laying hens raised under heat stress conditions. A total of 280 47-wk-old Hy-Line Brown laying hens were allotted to 1 of 4 dietary treatments with 7 replicates in a completely randomized design. Each replicate had 10 birds per cage. The basal diet was formulated to meet or exceed the requirement estimates for Hy-Line Brown laying hens. Three additional diets were prepared by adding 250 mg/kg VC, 250 mg/kg VE, or 3,000 mg/kg BT to the basal diet. The experimental diets and water were provided to hens on an ad libitum basis for 8 wk. Average daily room temperature and relative humidity were 30.7±1.41℃ and 72.5±11.61%, respectively. Results indicated that hens fed diets containing 250 mg/kg VE had a less (p<0.05) egg production rate than other dietary treatments. For egg quality, hens fed diets containing 3,000 mg/kg BT had a less (p<0.05) eggshell thickness than those fed the diets containing 250 mg/kg VC or 250 mg/kg VE. For antioxidant status, there was a tendency (p=0.09) for the least malondialdehyde (MDA) concentrations in the liver for BT treatment. A tendency (p=0.05) was observed for less blood heterophil:lymphocyte ratio in BT treatment as compared to other treatments. In conclusion, dietary supplementation of 250 mg/kg VC, 250 mg/kg VE, and 3,000 mg/kg BT has no beneficial effects on productive performance, egg quality, relative organ weights, liver visual characteristics, and immune responses of laying hens raised under the current heat stress conditions. However, dietary supplementation of 3,000 mg/kg BT alleviates antioxidant status and stress response of laying hens exposed to heat stress.
        4,200원
        5.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effect of waterlogging stress on the physiological response and growth characteristics of the five Italian ryegrass varieties. For all varieties, the germination rate of seed decreased by 10-15% as the waterlogging period increased, but the waterlogging stress treatment after the early seedling stage increased the growth of shoot and root length. Photosynthetic activity (Fv/Fm) according to waterlogging stress treatment decreased in all vareity, and Florida 80 showed the least decrease with 1.5%. Waterlogging stress treatment was found to reduce the accumulation of reactive oxygen species (malondialdehyde, MDA) and the activities of antioxidant enzymes. These results suggest that other mechanisms may be involved in the defense mechanism of Italian ryegrass against waterlogging stress, such as promoting root growth to escape from waterlogging stress, in addition to the antioxidant enzyme system.
        4,000원
        6.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the effects of job stress, job attitude, and social support on the relationship between client violence and social worker job response. The multi-mediating effect of job stress, job attitude, and social support between client violence and social worker job response was empirically analyzed. 257 social workers in social welfare facilities were analyzed using SPSS. The following conclusions were drawn. First, there was a significant correlation between client violence, job stress, job attitude, social support, and job response variables. Client violence was affecting variables related to social worker job response. Second, job stress, job attitude, and social support had multiple mediating effects. The parallel mediation effect and the serial mediation effect were verified. Third, job attitude was found to be a variable of multiple mediating effects. Fourth, job stress and social support were found to be double mediating effect variables. In response, programs and manuals suitable for the type of social welfare facilities and the policy basis for preparing countermeasures for social workers were limited, and follow-up studies on various variables were suggested.
        4,000원
        7.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Forage crop management is severely challenged by global warming-induced climate changes representing diverse a/biotic stresses. Thus, screening of valuable genetic resources would be applied to develop stress-tolerant forage crops. We isolated two NAC (NAM, ATAF1, ATAF2, CUC2) transcription factors (ANAC032 and ANAC083) transcriptionally activated by multi-abiotic stresses (salt, drought, and cold stresses) from Arabidopsis by microarray analysis. The NAC family is one of the most prominent transcription factor families in plants and functions in various biological processes. The enhanced expressions of two ANACs by multi-abiotic stresses were validated by quantitative RT-PCR analysis. We also confirmed that both ANACs were localized in the nucleus, suggesting that ANAC032 and ANAC083 act as transcription factors to regulate the expression of downstream target genes. Promoter activities of ANAC032 and ANAC083 through histochemical GUS staining again suggested that various abiotic stresses strongly drive both ANACs expressions. Our data suggest that ANAC032 and ANAC083 would be valuable genetic candidates for breeding multi-abiotic stress-tolerant forage crops via the genetic modification of a single gene.
        4,000원
        8.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        겨울철 도심지 내 적설 피해를 줄이기 위해 사용되고 있는 제설제는 주로 염화칼슘을 사용하고 있으며 주변에 식재 된 식물에 피해를 줄 수 있다. 본 연구는 제설제로 이용되는 염화칼 슘의 농도별 처리에 따른 가침박달(Exochorda serratifolia)의 생장과 생리적 반응을 알아보기 위해 수행되었다. 실험처리는 염화칼슘 0(대조구), 1.0, 3.0, 5.0%를 일주일 간격으로 1회 200mL씩 화분에 관주하였다. 염화칼슘 1.0, 3.0% 처리구에서 가침박달의 초장, 초폭, 엽장, 엽수, 생체중, 건물중간 통계적인 유의성은 없었지만 염화칼슘 5.0% 이상의 처리구에서는 가침박달의 초장이 짧아지고, 엽수가 줄어들었으며 생체중, 건물중이 유의적으로 낮았다. 총 엽록소 함량은 대조구를 제외한 모든 염화칼슘 처리구에서 낮게 측정되었고, MDA는 모든 염화칼슘 처리구에서 대조구보다 높게 측정된 것으로 보아 모든 염화칼슘 처리구에서 가침박달이 염스트레스를 받은 것으로 판단된다. 하지만 염화칼슘의 농도가 높아질수록 Proline 과 SOD 활성이 증가하여 가침박달의 항산화 반응을 확인하였다. 염화칼슘 5.0%를 제외하고는 모든 염화칼슘 처리구와 대조구의 생육이 비슷한 것으로 보아 가침박달은 내염성이 강한 식물종이라고 판단된다.
        4,000원
        9.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Aluminum (Al) stress in acidic pH is known to decrease the growth and productivity of alfalfa. However, not much is known about how the application of silicon (Si) affects the Al stress response in alfalfa. This study was conducted to evaluate the effect of exogenous application of Si on the growth of alfalfa seedlings exposed to Al stress in pots. Alfalfa seedlings grown in pots for 2 weeks were treated either Al stress (pH 4.0, 0.2 mM Al) or Al stress + Si (1 mM) for 5 days, lengths and biomass of shoot and root, and chlorophyll and carotenoid contents in leaf tissues were analyzed respectively. Al stress treatment inhibited shoot and root growth, and decreased fresh and dry weights, and chlorophyll content in leaves, but increased carotenoid content. In contrast, when alfalfa seedlings treated with Al stress combined with Si, delayed growth caused by Al stress of shoot and root of alfalfa seedlings was restored, dry weight was increased and chlorophyll content of leaf tissue was increased, but carotenoid content was decreased. These results suggest that Si has a function of alleviating Al toxicity in alfalfa, of which it exhibits a mitigating effect by a function that overlaps with some of the intracellular functions of carotenoids.
        4,000원
        11.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The occurrence of exotic weeds and their influx into farmlands due to climate change poses many problems. Therefore, it is necessary to generate a prediction model for the occurrence pattern of these exotic weeds based on scientific evidence and devise prevention measures. The photosynthetic apparatus is known as the most temperaturesensitive component of a plant cell and its initial response to temperature stress is to inhibit the activation of photosystem II. This study investigated the potential of OJIP transients in assessing temperature stress in exotic weeds. The four exotic weeds currently flowing into Korean farmlands include Amaranthus spinosus, Conyza bonariensis, Crassocephalum crepidioides, and Amaranthus viridis. These weeds were treated at 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, and 40°C and the OJIP curves and JIP parameters were measured and analyzed. The results showed that heat and chilling stress affected the photosystem II (PSII) electron transport of A. spinosus, whereas C. crepidioides and A. viridis were more affected by high-temperature stress than by low-temperature stress. Lastly, C. bonariensis showed resistance to both high and low-temperature stress. The results of this study suggest that OJIP transients and JIP parameters can be used to analyze damage to the photosynthetic apparatus by temperature stress and that they can serve as sensitive indicators for the occurrence pattern of exotic weeds.
        4,200원
        13.
        2018.12 구독 인증기관 무료, 개인회원 유료
        To investigate effects of starvation on physiological changes, stress response, and survival of cobitid loach (Misgurnus anguillicaudatus) exposed to sodium nitrite (NaNO2), a 4- week experiment was conducted. Fewer fish survived in the starved group than those in the fed group during the experiment. Starvation resulted in growth retardation, leading to differences in body length and body depth between fed and starved groups. The fed gorup continued to grow and remained in good condition. Blood chemical analysis (plasma cortisol and glucose) showed significant differences in stress response to nitrite exposure between fed and starved groups (p < 0.05). These results suggest that all parameters employed in this study to assess effects of starvation with NaNO2 stress are useful information for researching nutritional status in cobitid loach.
        4,000원
        14.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 요가와 명상 중심의 산림치유 프로그램이 성인의 기분상태와 스트레스 반응에 미치는 효과에 대하여 검증하고자 하였다. 실험에 동의한 성인 17명을 대상으로 강원도 홍천군 소재의 치유의 숲에서 2017년 9월 8일부터 10일까지 2박 3일 동안 실시하였다. 측정도구는 단축형 기분상태 척도(K-POMS-B: Korean version of Profile of Mood States-Brief)와 스트레스 반응 척도(Stress Response Inventory)를 사용하였다. 자료분석은 SPSS 24.0 프로그램을 사용하여 대응표본 t-검정을 통해 프로그램 참가 전과 후의 기분상태와 스트레스 반응 차이를 살펴보았다. 요가와 명상 중심의 산림치유 프로그램이 성인의 기분상태에 영향을 미치는가를 알아본 결과, 기분상태 총점은 통계적으로 유의미하게 감소하였다. 하위척도 중 활기는 증가하였으나 통계적으로 유의미하지 않았고 긴장, 우울, 분노, 피로, 혼돈은 통계적으로 유의하게 감소하였다. 요가와 명상 중심의 산림치유 프로그램에 참여한 성인의 스트레스 반응에 영향을 미치는가를 알아본 결과, 스트레스 반응은 통계적으로 유의미하게 감소하였다. 하위척도 중 공격성을 제외한 긴장, 신체화, 분노, 우울, 피로, 좌절은 통계적으로 유의미하게 감소하였다. 본 연구 결과가 향후 요가와 명상 중심의 산림치유 프로그램의 효과를 밝히는 기초자료로 활용될 수 있기를 기대한다.
        4,000원
        15.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 열 스트레스 (heat stress, HS)에 노출된 브로일러에서 혼합 생균제의 급여가 혈 액 생체지표, 면역반응, 맹장 미생물 및 생산성에 미치는 영향을 조사하였다. 총 400마리의 브로일러 수 컷 (Ross 308)을 각각 100마리씩 4그룹, C (대조군, 실온 25℃), HS (열 스트레스 33℃), HSP (HS플 러스 혼합 생균제 500, 750 mg/kg) 그룹으로 배치하였다. 브로일러의 증체량, 사료섭취, 사료요구율 및 면역기관 무게는 HSP 그룹에서 HS 그룹과 비교했을 때 증가하였다. 혈액 IgG, lymphocytes 농도는 HS 그룹에서 HSP그룹과 비교했을 때 증가하였고, heterophil과 lymphocyte(H:L)비율, 코르티코스테론 농도 및 폐사율은 낮았다. 맹장의 Lactobacillus는 HS 그룹과 비교했을 때 HSP 그룹에서 증가하였으나 Escherichia coli (E. coli), coliform bacteria, aerobic bacteria는 낮아졌다. 본 연구결과는 열 스트레스 에 노출된 브로일러에게 B. subtilis, S. galilaeus 및 Sphingobacteriaceae등 3가지 균주가 포함된 혼합 생균제를 급여해주면 면역반응 증진, 미생물 균형을 유지해줌으로써 폐사율을 낮추고 생산성을 개선할 수 있음을 시사해준다.
        4,000원
        16.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 열 스트레스 (heat stress, HS)에 노출된 산란계에서 혼합 생균제의 급여가 생산성, 계란품질, 면역반응, 맹장 미생물 및 분 암모니아에 미치는 효과를 조사하였다. 총 400마리의 50주령 Hy-Line brown 산란계를 무작위로 각각 100마리씩 4 그룹, C (대조군, 실온 25℃), HS (열 스트레스 33℃), HSP (HS 플러스 혼합 생균제 500, 750 mg/kg)로 배치하였다. 산란계의 생산성, 계란품질, 비장 무게, 혈액 IgG 및 lymphocyte 농도는 HSP 그룹에서 HS 그룹과 비교했을 때 증가하였고, 코르티코스테론, heterophil과 lymphocyte의 비율 (H:L) 및 폐사율은 유의하게 낮았다. Lactobacillus는 HSP 그룹에서 HS 그룹과 비교했을 때 증가하였으나 Escherichiacoli (E. coli), coliform bacteria 및 aerobic bacteria는 유의하게 낮았다. 분에서 암모니아 발생은 HS 그룹이 HSP 그룹에 비해서 유의하게 증가하였다. 결론적으로, 이러한 혼합 생균제가 여름철 산란계의 더위 피해를 방해주고 면역반응, 맹장 미생물 균형을 경유하여 생산성, 계란품질 및 계분으로부터 악취 발생을 줄이는 데 효율적인 영양전략이 될 수 있음을 나타낸다.
        4,000원
        18.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study evaluated the effect of reduced glutathione (GSH) for the reduction of stress and inflammatory response in calves inoculated with foot-and-mouth disease (FMD) vaccine. Twenty-five calves were divided into five groups of 5 calves. The negative control (NC) did not receive any vaccination or drug treatment. The positive control (PC), GSH-25, GSH-50 and GSH-100 were intramuscularly injected with GSH at concentrations of 0, 25, 50 and 100 mg / 10 kg body weight (BW), respectively, for 3 days after FMD vaccination. On day 3, 5 and 7 post-treatment, the serum cortisol and tumor necrosis factor- α (TNF-α) levels in GSH-50 and GSH-100 were significantly decreased compared with those in PC (p < 0.05). However, there was no significant difference in the serum cortisol and TNF-α levels between GSH-100 and NC 3 and 5 days post-treatment, and between GSH-50, GSH-100, and NC 7 days post-treatment. The results from this study suggest that treatment of 50 mg / 10 kg BW GSH for 3 days is useful for the reduction of stress and inflammatory response caused by FMD vaccination in calves.
        3,000원
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