• Title/Summary/Keyword: Stress adaptation

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Assessment of Methane Production Rate Based on Factors of Contaminated Sediments (오염퇴적물의 주요 영향인자에 따른 메탄발생 생성률 평가)

  • Dong Hyun Kim;Hyung Jun Park;Young Jun Bang;Seung Oh Lee
    • Journal of Korean Society of Disaster and Security
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    • v.16 no.4
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    • pp.45-59
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    • 2023
  • The global focus on mitigating climate change has traditionally centered on carbon dioxide, but recent attention has shifted towards methane as a crucial factor in climate change adaptation. Natural settings, particularly aquatic environments such as wetlands, reservoirs, and lakes, play a significant role as sources of greenhouse gases. The accumulation of organic contaminants on the lake and reservoir beds can lead to the microbial decomposition of sedimentary material, generating greenhouse gases, notably methane, under anaerobic conditions. The escalation of methane emissions in freshwater is attributed to the growing impact of non-point sources, alterations in water bodies for diverse purposes, and the introduction of structures such as river crossings that disrupt natural flow patterns. Furthermore, the effects of climate change, including rising water temperatures and ensuing hydrological and water quality challenges, contribute to an acceleration in methane emissions into the atmosphere. Methane emissions occur through various pathways, with ebullition fluxes-where methane bubbles are formed and released from bed sediments-recognized as a major mechanism. This study employs Biochemical Methane Potential (BMP) tests to analyze and quantify the factors influencing methane gas emissions. Methane production rates are measured under diverse conditions, including temperature, substrate type (glucose), shear velocity, and sediment properties. Additionally, numerical simulations are conducted to analyze the relationship between fluid shear stress on the sand bed and methane ebullition rates. The findings reveal that biochemical factors significantly influence methane production, whereas shear velocity primarily affects methane ebullition. Sediment properties are identified as influential factors impacting both methane production and ebullition. Overall, this study establishes empirical relationships between bubble dynamics, the Weber number, and methane emissions, presenting a formula to estimate methane ebullition flux. Future research, incorporating specific conditions such as water depth, effective shear stress beneath the sediment's tensile strength, and organic matter, is expected to contribute to the development of biogeochemical and hydro-environmental impact assessment methods suitable for in-situ applications.

The Role of Plant Fatty Acids in Regulation of the Adaptation of Organisms to the Cold Climate in Cryolithic Zone of Yakutia (야쿠티아의 동토지역에 서식하는 생물의 추운기후-순화의 조절에서 식물 지방산의 역할)

  • Petrov, Klim Alekseevich;Dudareva, Lyubov Vissarionovna;Nokhsorov, Vasilii Vasilevich;Perk, Aleksandr Aleksandrovich;Chepalov, Valentin Azotovich;Sophronova, Valentina Egorovna;Voinikov, Victor Kirillovich;Zulfugarov, Ismayil S.;Lee, Choon-Hwan
    • Journal of Life Science
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    • v.26 no.5
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    • pp.519-530
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    • 2016
  • Vegetative plants in Yakutia are naturally frozen when they are covered with snow in the fall, and they function as green cryo-fodder that is a source of biologically active substances and nutrients for herbivorous animals. We observed a considerable increase in the total fatty acid content in the leaves of Avena sativa, Elytrigia rеpens, Equisetum variegatum and Equisetum scirpoides during the fall period. However, the degree of unsaturation of fatty acids was not higher in the frozen plants covered with snow than in the summer plants, with the exception of E. scirpoides, a dwarf horsetail found in the Pole of Cold in the northern hemisphere. In the internal adipose tissue of the Yakut horse (young horse meat), 18 fatty acids were found, including 10 saturated ones. Monounsaturated oleic С18:1 (n-9) acid and polyunsaturated α-linolenic С18:3 (n-3) acid were equally prevalent among the unsaturated fatty acids, accounting for 70% of the total unsaturated fatty acids. This composition of polyenoic fatty acids in the internal adipose tissue indicates that the Yakut horse actively feeds on the fall vegetation and the wintergreen sedge-grass. We believe that the high plant-specific free fatty acid content in the tissue of Yakut horses may play an important role in the regulation of their resistance to long-term low-temperature stress.

Cold Pressor Response to Seasonal Variation in Winter and Summer (국소한냉자극이 전신 및 국소혈액순환에 미치는 영향 -제 2 보 : 동계 및 하계의 계절변화에 따른 한냉반응-)

  • Park, Won-Gyun;Chae, E-Up
    • The Korean Journal of Physiology
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    • v.17 no.2
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    • pp.93-101
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    • 1983
  • A possibility whether the appearance of adaptation to cold climate during winter could occur or not in Taegu area was evaluated by comparing the data obtained in winter with that obtained by the same method in summer. Circulatory response was induced by the immersion of one hand in the cold water. The systemic and local responses in the blood circulation from the immersed hand and the unimmersed opposite hand were observed simultaneously. In addition Galvanic skin resistance(GSR) that is influenced by the activity of autonomic nervous system and the vascular tonicity was recorded. The experiment was performed by examining sixty healthy college students in winter and fifty in summer, whose mean age was 21.0, mean weight $60.6{\pm}0.90\;kg(male)$ and $48.3{\pm}0.98\;kg(female)$. The cold stimulus was applied by immersing the left hand into the cold water of $5^{\circ}C$ for 3 minutes, and the response was observed on immersed left hand and unimmersed right hand simultaneously. The observation was made through determining mean blood pressure, heart rate, amplitude of photoelectric capillary pulse (APCP) and GSR. The results obtained are as follows: The mean blood pressure was elevated during the cold stimulation. The increase of blood pressure in summer was more remarkable than in winter. At the recovery period the blood pressure was decreased to the control level in winter but the decrease below the control level was observed in summer. The increase of heart rate in summer was more remarkable than in winter during the cold stimulation. At the recovery period heart rate in both winter and summer was decreased below the control level. During the cold stimulation the APCP was decreased on both hands in winter. However it was more prominent on left hand indicating additional direct cold effect on immersed hand. In summer, the decrease of APCP during immersion was less remarkable than that in winter, but the regain of APCP was faster than that in winter at the recovery period. And the prompt increase of APCP over the control level has been obtained at the 3 minutes of the recovery period. The GSR was remarkably increased on immersed hand but slightly decreased on unimmersed opposite hand during the cold stimulation. Thus the finding on immersed hand indicates that the local direct effect of cold water is more prominent than the systemic effect, where as the finding on unimmersed hand indicates that the circulatory response to painful stress elicited by the cold stimulation is more prominent than cold temperature itself. In summary, it seems that the systemic circulatory response to the local cold stimulation of the one hand is arised more from the secondary elicited pain sensation and less from the low water temperature. On the contrary to the report of Kim et $al^{39)}$, the adaptation phenomena in blood pressure to the relatively mild cold climate in winter was not observed in this study. The difference of circulatory response observed in this study between winter and summer may be due to the difference of the magnitude of subjective sensation of the cold water stimulation by the seasonal changes in air temperature.

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Anti-depressant Effect of Herbal Extracts in the Chronic Mild Stressed Rat (Mild stressed rat을 이용한 수종한약의 항우울효과에 대한 실험적 연구)

  • Yoon Jeong Hwan;Shin Dong Won;Bae Hyun Su;Shin Min Kyu;Hong Moo Chang
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.1
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    • pp.113-117
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    • 2003
  • This study was performed to investigate the anti-depression effect of herbal extracts (Rehmanniae Radix Preparat, Corni Fructus, Lycii Fructus, Pinelliae Rhizoma, Nelumbinis Semen) in the chronic mild stressed rat. After adaptation period for 2 weeks, each herbal extract was administered to the rats divided 5 groups. For comparison, St. John's wart was administered to another group in the same environment. The chronic mild stress was induced to rats by overnight illumination for 2 days before the forced swimming test. Struggling time, first latency and rest duration were calculated during the forced swimming test to evaluate the anti-depressant effect. The results were as follows: 1. In the result of evaluation of the struggling time, there was no significance in Pinelliae Rhizoma (-1.1%), Corni Fructus (-3.9%), Rehmanniae Radix Preparat (15.2%), Lycii Fructus (4.9%), St. John's wart (25.2%). There was a significant increase only in Nelumbinis Semen (43.9%) (P=0.0037). 2. In the result of evaluation of the first latency time, there was no significance in Lycii Fructus (-21.37%), Rehmanniae Radix Preparat (38.4%), Pinelliae Rhizoma (65.5%), Corni Fructus (29.2%), St. John's wart (75.8%). There was a significant increase only in Nelumbinis Semen (90.2%) (P=0.0116). 3. In the result of evaluation of the first rest duration, there was no change in St. John's wart, and Decrease was shown in Pinelliae Rhizoma (62.4%), Corni Fructus (31.6%) Rehmanniae Radix Preparat (63.1 %), Lycii Fructus (12.4%), Nelumbinis Semen (59.0%), but there was no significance in all. 4. Nelumbinis Semen is considered to have a superior anti-depression effect than the other herbal extracts, and to have a superior and-depression effect than St. John's wart being used commonly.

Association of p53 Expression with Metabolic Features of Stage I Non-Small Cell Lung Cancer

  • Kang, Shin-Myung;Koh, Won-Jung;Suh, Gee-Young;Chung, Man-Pyo;Han, Joung-Ho;Kim, Ho-Joong;Kwon, O-Jung;Um, Sang-Won
    • Tuberculosis and Respiratory Diseases
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    • v.71 no.6
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    • pp.417-424
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    • 2011
  • Background: Recent evidences have revealed metabolic functions of p53 in cancer cells; adaptation or survival to metabolic stress and metabolic shift toward oxidative phosphorylation. However, further studies in clinical setting are needed. We investigated whether p53 protein expression, as a surrogate marker for loss of p53 function, is associated with metabolic features of stage I non-small cell lung cancer (NSCLC), focusing on tumor necrosis and maximal standardized uptake value (SUVmax) on $^{18}F$-fluorodeoxyglucose positron emission tomography. Methods: Clinical information was obtained from retrospective review of medical records. p53 expression was assessed by immunohistochemical staining. Results: p53 protein expression was detected in 112 (46%) of 241 NSCLC cases included in this study. p53 expression was independently associated with the presence of necrosis (odds ratio [OR], 2.316; 95% confidence interval [CI], 1.215~4.416; p=0.011). Non-adenocarcinoma histology (OR, 8.049; 95% CI, 4.072~15.911; p<0.001) and poorly differentiation (OR, 6.474; 95% CI, 2.998~13.979; p<0.001) were also independently associated with the presence of necrosis. However, p53 expression was not a significant factor for SUVmax. Conclusion: p53 protein expression is independently associated with the presence of necrosis, but not SUVmax.

Effect of Reverse Feeding on the Reproductive System in Male Rats

  • Jeon, Eun-Young;Lee, Sung-Ho
    • Development and Reproduction
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    • v.16 no.3
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    • pp.227-233
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    • 2012
  • Circadian timing system plays a major role in a wide range of reproductive function. However it is plausible idea that other environmental and/or internal cue might be simultaneously participated in the optimal regulation of reproductive system. In the present study we extended the reverse feeding (RF) time regimen up to 8 weeks, then measured the general and reproductive indices of the animals. The animals of ad libitum feeding group (Control, CON) have free access to food for 4, 6 and 8 weeks, respectively. The day feeding animals (reverse feeding, RF group) have restricted access to food during daytime (09:00-18:00) for 4, 6 and 8 weeks, respectively. When the feeding schedules were over, key indices were measured. After 4 weeks and 8 weeks of feeding, body weights of animals were not significantly different. However, body weights of 6 weeks RF animals were significantly smaller than those of control animals (CON : RF = $333.46{\pm}12.71$ g : $289.91{\pm}8.31$ g, p<0.01). The blood glucose levels of 4 weeks RF animals were significantly decreased compared to the levels of control animals (CON : RF = $161.4{\pm}2.7$ mg/dL : $176.7{\pm}5$ mg/dL, p<0.01) while the levels of 6 weeks RF and 8 weeks RF animals were not different form those of control animals. Reproductive and non-reproductive tissue weights from 6 weeks RF group were significantly lowered than those from CON group (testis, CON : RF = $1.4714{\pm}0.0174$ g : $1.3724{\pm}0.0168$ g, p<0.001; epididymis, CON : RF = $0.3574{\pm}0.0059$ g : $0.3243{\pm}0.0068$ g, p<0.001; seminal vesicle, CON : RF = $0.1655{\pm}0.0068$ g : $0.1328{\pm}0.0054$ g, p<0.001; prostate, CON : RF = $0.3350{\pm}0.0231$ g : $0.2528{\pm}0.0143$ g, p<0.01). After 4 weeks and 8 weeks of reverse feeding, sperm counts in RF animals were markedly reduced than those in control animals[CON 4W : RF 4W = $121.17{\pm}9.96\;({\times}10^6)$ : $50.86{\pm}9\;({\times}10^6)$, p<0.001; CON 8W : RF 8W= $138.69{\pm}9.8\;({\times}10^6)$ : $108.94{\pm}4.22\;({\times}10^6)$, p<0.001]. Present study indicates that RF may induce an adaptable metabolic stress and cause impairment of androgen-dependent reproductive tissues. On-going longitudinal studies will allow a better understanding of the how does mealtime shift affect the reproductive function and exact nature of adaptation.

Concept Development of Resilience (회복력 (Resilience) 개념 개발)

  • 김혜성
    • Journal of Korean Academy of Nursing
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    • v.28 no.2
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    • pp.403-413
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    • 1998
  • The Resilience is described as the personal capacity which brings psychosocial comeback. The role of nursing is to do its best to rehabilitate patients and to explore the individual in order to promote patients psychosocial change. However, as the current nursing is heavily physical nursing oriented, the identity of the nursing would be lost. Therefore this researcher reviewed if the concept of resilience can be applied to the nursing after examing the concept of resilience by Documents and Fieldwork. The methodology of this research is Hybrid Model developed by Schwartz-Barcott and Kim for the concept development and analysis. The process and procedure consist of The Theoretical Phase, The Fieldwork Phase and The Final Analytical Phase in accodance with the Hybrid Model. The followings the summary of the Research. 1. The Concept of Resilience Finally Analyzed by Documents and Fieldwork (1) The Redefinition of Resilience The resilience is the latent psychosocial capacity which minimize the negative emotion and promote the adaptation under adversity. Resilience appears as cognitive, emotional and behavioral response in the course of changing from negative response to positive response through the interaction of the individual and the enviroments in a given time. Resilience changes and decreases according to time and situation and it can be nurtured. Resilience is the higher concept including hardiness, sense of coherence and self-strength which maintain the health under stress. (2) The Attribute of Resilience The attribute of resilience was devided into psychological and social dimension. In psychological attributes, there are admittion of reality of situation, denial of negative emotion, desire to live, responsibility, confidence, courage, hope, pursuit of positive meaning, identification and pursuit of goal, self-esteem, reception, spontaneity, planning, positiveness, will power, flexibility and creativity. In social attributes, there are a sense of belonging, perception of social support and active social relations. (3) The Process of Resilience There are 4 resilience phases which were the process minimizing the possibility of the negative chain reactions under adversity, the process minimizing the negative emotion under adversity, the process gaining the desire to live and the process exposing the active social relations. 2. The Application Possibility of Resilience Concept to Nursing The resilience concept is the psychosocial capacity with which an individual manages adversity. As many nursing scientists have developed nursing theory based on this capacity and the identification of nursing has been established in this field, resilience is not the new conception in nursing. However, since resilience appears in the attributes related with the resilience process concretely, it would help a lot when nurses execute psychosocial nursing.

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Predicting Health-Promoting Behaviors in Patients with Stomach Cancer (건강증진행위의 영향요인 분석 -위암환자중심 -)

  • 오복자
    • Journal of Korean Academy of Nursing
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    • v.25 no.4
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    • pp.681-695
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    • 1995
  • It has been noted that a genetic alteration of cells influenced by unhealthy lifestyle In addition to a series of other carcinogens increases various neoplasmic diseases. Therefore the importance of lifestyle that minimizes such impact on health should be emphasized. Since stomach cancer, the most common neoplasmic disease in Korea, is re-lated to the Korean lifestyle and as there's a possibility of its recurrence, people with stomach cancer need to lead a healthy lifestyle. The purpose of this study is to provide a basis for nursing intervention strategies to promote health promoting behaviors that are constructive to a healthy lifestyle. A multivariate model was constructed based on the fender's health promotion model and Booker's health belief model by including influential factors such as hope. The sample was composed of 164 patients with stomach cancer who visited outpatient clinics of a university hospital in Seoul. The following instruments were used in the study after some adaptation : Wallston and others' multidimensional health locus of control scale Laffrey's health conception scale, Lawston and others' health self- rating scale, Walker and others' health promotion lifestyle profile and Rogenberg's self esteem scale. In addition Moon's health belief scale was used with some modification. For self efficacy, the present author constructed a self-efficacy scale based on previous research. The above mentioned instruments were tested in a pilot study with 24 patients with stomach cancer. The reliabilities of instruments were tested with Cronbach's alpha(0.574∼0.949). Data were analyzed using a SAS program (or Pearson correlation coefficients, descriptive correlational statistics and stepwise multiple regression. The results are as follows : 1. The scores on the health promoting behavior scale ranged from 55 to 145 with a mean of 107.91 (S. D : 16.50). The mean scores(range 1-4) on the different dimensions were nutrition 3.14, exercise 2.48, stress management 2.69, health responsibility 2.65, interpersonal relationship 2.878E self actualization 2.85. 2. There were significant correlations among all the predictive variables & the health promoting behavior (r=.20-.55, p〈.01) 3. Stepwise multiple regression analysis showed that : 1) Hope was the main predictor and accounted for 29.8% of the total variance. 2) Self efficacy, perceived barriers & self esteem accounted for an additional 14.6% of the total variance. 3) Hope, self efficacy, perceived barriers & self esteem altogether accounted for 44.3% of the total variance. In conclusion, hope, self efficacy, perceived barriers & self esteem were identified as important variables that contributed to promote health promoting behavior.

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Concept Analysis of Tae-um in Nurses (간호사의 태움 개념분석)

  • Jeong, Sun-Kyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.8
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    • pp.482-491
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    • 2018
  • This study was conducted to identify the conceptual definition and attributes of nurses' Tae-um based on the conceptual analysis method of Walker and Avant. The attributes of nurses' Tae-um were derived from the organizational culture, inexperienced new nurses that are victims, senior nurses that are perpetrators, alteration of teaching, verbal and physical violence experiences, and psychological and physical symptoms. The antecedents were due to excessive work, high work intensity, job stress, lack of workforce, poor working environment, lack of job ability of new nurses, organizational hierarchy, and power imbalance. Moreover, the consequences were physical and psychological symptoms, decreased efficiency, increased distrust, increased turnover intention, and decreased quality of patient care. Improvements of working conditions and social supports for expanding nursing staff and building a culture in which communication and mutual cooperation are used to solve the antecedents of Tae-um among nurses is necessary. This study suggests the need for more qualitative research on Tae-um in nurses, the development of tools that reflect the attributes of Tae-um in nurses, and the development of a program to improve the culture of Tae-um in nurses. This study is significant in that it provides a rationale for development of an adaptation program for new nurses by suggesting the antecedents of Tae-um and solutions for it.

Trends and Future Tasks of Domestic Research on Career Guidance in Art Colleges (예술대학 진로지도에 관한 국내 연구동향과 향후 과제)

  • Koo, Eun-Ja
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.2
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    • pp.508-515
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    • 2018
  • This study aims to analyze trends in domestic research concerning career guidance for college students majoring in arts, and to provide implications for future research. To this end, a total of 74 papers including journal articles, master's theses, and doctoral dissertations published from 2006-2016 were analyzed in terms of research period, research topic, research methods, study subjects' gender, years in college, and field of study in the arts. Research topics were analyzed according to six criteria, and results showed that there were 24 studies concerning topics related to adaptation/ behaviors/ experiences, including career-related stress, career maturity, anxiety, preparation and development competences, accounting for 32.5% of the total. In terms of gender, 96% of research included both male and female students, and three were conducted only for female students. In terms of year of study, 49 studies examined students in all years of study considered students in all years, accounting for 66% of the sample. Trends in research methods were characterized by the quantitative method applied in the study. Regarding the field of study in the arts, 54 studies were conducted in the field of dance (ballet, Korean dance, and contemporary dance), accounting for 73% of the total. In addition, topics in the field of dance were evenly covered by these studies. Most studies concerning career guidance in art colleges were difficult to categorize due to the small number of studies conducted in the sample. It is suggested that future research reflects various perspectives, social issues, students' majors, year of study, and gender using various research methods.