• Title/Summary/Keyword: 기술 스트레스

Search Result 1,703, Processing Time 0.041 seconds

Changes in water quality and hematological parameters according to the stocking density of olive flounder, Paralichthys olivaceus raised in bio-floc environment (바이오플락 양식기술 적용 넙치, Paralichthys olivaceus 수용밀도에 따른 수질변화 및 혈액학적 성상 변화)

  • Kim, Jun-Hwan;Jeong, Eun-Ha;Kim, Seok-Ryel;Kim, Su Kyoung;Kim, Su-Kyoung;Hur, Young Baek
    • Korean Journal of Environmental Biology
    • /
    • v.37 no.2
    • /
    • pp.155-163
    • /
    • 2019
  • The Paralichthys olivaceus (mean weight 34.3±3.5 g) was used in the conduction of density experiment in this study to establish the optimal density determination for a period of 13 weeks. The density consisted of four groups. These were group 1 (500 fish, 40 fish m-2), group 2 (750 fish, 60 fish m-2), group 3 (1,000 fish, 80 fish m-2) and group 4 (1,250 fish, 100 fish m-2), each in 12.56 ㎡ circular water tanks. In the high density groups, such as groups 1 and 2, the nitrite was increased to over 21 mg L-1 (group 3) and 25 mg L-1 (group 4). The experiment of the groups was terminated by skin ulcers and mortality after 49 days for group 3 and 43 days for group 4. The water quality environment, such as the water temperature, dissolved oxygen, salinity and pH, remained constant. The ammonia and nitrite in groups 1 and 2 remained stable after ammonia and nitrite peak. However, the experiments in groups 3 and 4 were terminated due to the mortality induced by high nitrite. Hematological parameters, such as hemoglobin and hematocrit, were significantly decreased in the high density groups. The plasma components were significantly changed in the high density groups, such as groups 3 and 4. The mean weight of groups 1 and 2 after 13 weeks were 91.3 g and 83.7 g, respectively. The survival rates were 99.4% and 98.2%, respectively. The final FCR was 0.6 in both groups. The results of this study show that the density of 80 fish m-2 or more induce mortality due to high nitrite with hematological changes. Additionally, they indicate that the 60 fish m-2 indicate proper density in bio-floc environment in olive flounder weighing less than 100 g.

Current status and prospects of molecular marker development for systematic breeding program in citrus (감귤 분자육종을 위한 분자표지 개발 현황 및 전망)

  • Kim, Ho Bang;Kim, Jae Joon;Oh, Chang Jae;Yun, Su-Hyun;Song, Kwan Jeong
    • Journal of Plant Biotechnology
    • /
    • v.43 no.3
    • /
    • pp.261-271
    • /
    • 2016
  • Citrus is an economically important fruit crop widely growing worldwide. However, citrus production largely depends on natural hybrid selection and bud sport mutation. Unique botanical features including long juvenility, polyembryony, and QTL that controls major agronomic traits can hinder the development of superior variety by conventional breeding. Diverse factors including drastic changes of citrus production environment due to global warming and changes in market trends require systematic molecular breeding program for early selection of elite candidates with target traits, sustainable production of high quality fruits, cultivar diversification, and cost-effective breeding. Since the construction of the first genetic linkage map using isozymes, citrus scientists have constructed linkage maps using various DNA-based markers and developed molecular markers related to biotic and abiotic stresses, polyembryony, fruit coloration, seedlessness, male sterility, acidless, morphology, fruit quality, seed number, yield, early fruit setting traits, and QTL mapping on genetic maps. Genes closely related to CTV resistance and flesh color have been cloned. SSR markers for identifying zygotic and nucellar individuals will contribute to cost-effective breeding. The two high quality citrus reference genomes recently released are being efficiently used for genomics-based molecular breeding such as construction of reference linkage/physical maps and comparative genome mapping. In the near future, the development of DNA molecular markers tightly linked to various agronomic traits and the cloning of useful and/or variant genes will be accelerated through comparative genome analysis using citrus core collection and genome-wide approaches such as genotyping-by-sequencing and genome wide association study.

Estimation of Soil Cooling Load in the Root Zone of Greenhouses (온실내 근권부의 지중냉각부하 추정)

  • 남상운
    • Journal of Bio-Environment Control
    • /
    • v.11 no.4
    • /
    • pp.151-156
    • /
    • 2002
  • Root zone cooling, such as soil or nutrient solution cooling, is less expensive than air cooling in the whole greenhouse and is effective in promoting root activity, improving water absorption rate, decreasing plant temperature, and reducing high temperature stress. The heat transfer of a soil cooling system in a plastic greenhouse was analyzed to estimate cooling loads. The thermal conductivity of soil, calculated by measured heat fluxes in the soil, showed the positive correlation with the soil water content. It ranged from 0.83 to 0.96 W.m$^{[-10]}$ .$^{\circ}C$$^{[-10]}$ at 19 to 36% of soil water contents. As the indoor solar radiation increased, the temperature difference between soil surface and indoor air linearly increased. At 300 to 800 W.m$^{-2}$ of indoor solar radiations, the soil surface temperature rose from 3.5 to 7.$0^{\circ}C$ in bare ground and 1.0 to 2.5$^{\circ}C$ under the canopy. Cooling loads in the root zone soil were estimated with solar radiation, soil water content, and temperature difference between air and soil. At 300 to 600 W.m$^{-2}$ of indoor solar radiations and 20 to 40% of soil water contents,46 to 59 W.m$^{-2}$ of soil cooling loads are required to maintain the temperature difference of 1$0^{\circ}C$ between indoor air and root zone soil.

Properties of the Silkworm (Bombyx mori) Dongchunghacho, a Newly Developed Korean Medicinal Insect-borne Mushroom: Mass-production and Pharmacological Actions (한국에서 개발된 곤충유래 약용버섯인 누에동충하초의 생산기술개발 및 약리학적 특성)

  • Lee, Sang Mong;Kim, Yong Gyun;Park, Hyean Cheal;Kim, Keun Ki;Son, Hong Joo;Hong, Chang Oh;Park, Nam Sook
    • Journal of Life Science
    • /
    • v.27 no.2
    • /
    • pp.247-266
    • /
    • 2017
  • Cordyceps is a traditional Chinese medicinal herb well-known in China, Korea and Japan since B.C. 2,000. The original entomopathogenic fungus, Cordyceps sinensis belonging to the genus Cordyceps could not be found inside Korean peninsula due to the absence of the host insect for the corresponding entomogenous fungus. The development of artificial production methods of Korean type Cordyceps using the silkworm Bombyx mori as in vivo culture medium for the the entomopathogenic fungus Paecilomyces tenuipes is the first, and wonderful occasion in the research history of insect industry of this global world. The aim of this article is to review the historical research background, mass-production methods, and pharmacological effects of the silkworm-dongchunghacho (Paecilomyces tenuipes) which is a newly developed Korean medicinal insect-borne mushroom, and another non-insect-borne medicinal mushroom (Cordyceps militaris and Cordyceps pruinosa). Their biological actions include anti-tumor, immunostimulating, anti-fatigue, anti-stress, anti-oxidant, anti-aging, anti-diabetic, anti-inflammatory, anti-thrombosis, hypolipidaemic and insecticidal effects. The bioactive principles are protein-bound polysaccharides (hexose, hexosamin), cordycepin, D-manitol, acidic polysaccharide etc. Protein-bound polysaccharides and n-butanol fractions were demonstrated to show a significant anti-tumor activities but did not show a cytotoxicities. D-mannitol exhibited a significant prolongation of the life span in tumor bearing mice. Ergosterol did not show an efficient anti-tumor activity, but showed a significant phagocytosis enhancing activity. Anti-tumor activity of silkworm-dongchunghacho might be attributed to immuno-stimulating activities rather than cytotoxic effects [164]. Also this review comprises the breeding of Dongchunghacho varieties, optimization of culture conditions, improvement of learning and memory by Dongchunghacho, application of them as foods and chemical constituents.

Stable Inheritance of an Integrated Transgene and Its Expression in Phenylethylisothiocyanate-Enriched Transgenic Chinese cabbage (Phenylethylisothiocyanate 함량이 증진된 형질전환 배추에서의 도입유전자의 후대 유전 및 발현 안정성 검정)

  • Park, Ji-Hyun;Kim, Hyoung-Seok;Lee, Gi-Ho;Yu, Jae-Gyung;Park, Young-Doo
    • Horticultural Science & Technology
    • /
    • v.34 no.1
    • /
    • pp.112-121
    • /
    • 2016
  • Development of genetically-modified (GM) crops enables the introduction of new traits to the plant to confer characteristics such as disease resistance, herbicide resistance and human health-promoting bioactivity. Successful commercialization of newly developed GM crops requires stable inheritance of integrated T-DNA and newly introduced traits through the multiple generations. This study was carried out to confirm the stable inheritance of the integrated T-DNA in $T_1$ and $T_2$ transgenic Chinese cabbage (Brassica rapa ssp. pekinensis) that was genetically modified to increase concentrations of phenylethylisothiocyanate (PEITC), which is a potential anti-carcinogenic phytochemical. For this purpose, the IGA 1-3 ($T_1$ generation) and IGA 1-3-5 ($T_2$ generation) lines were selected by PCR and a IGA 1-3 transgenic plant ($T_1$ generation) was analyzed to confirm the T-DNA insertion site in the Chinese cabbage genome by VA-TAIL PCR. The results of this study showed that the introduced T-DNA in IGA 1 line was stably inherited to the next generations without any variations in terms of the structure of the transgenes, and this line also showed the expected transgene function that resulted in increased concentration of PEITC through the multiple generations. Finally, we confirmed the increased QR activity in IGA 1 $T_1$ and $T_2$ transgenic lines, which indicates an enhanced potential anti-carcinogenic bioactivity and its stable inheritance in IGA1 $T_1$ and $T_2$ transgenic lines.

The Phenomenological Study on School Dropout of Specialized Vocational High School Students (특성화고등학교 학생의 학업중단에 대한 현상학적 연구)

  • Lee, Myung-Hun
    • 대한공업교육학회지
    • /
    • v.44 no.1
    • /
    • pp.23-51
    • /
    • 2019
  • The purpose of this study was to analysis school dropout of specialized vocational high school students using phenomenological research method. The interview for the research was carried out with 10 adolescents who dropped out specialized vocational high school from December 8 to 23, 2018. According to the result of the research, 31 themes were extracted from interviews with 10 research participants. And 10 theme clusters were categorized from these. And these clusters were divided into 3 domains : 'before school dropout', 'causes & process of school dropout, feeling about school dropout', 'after school dropout' Based on the finding of the study, major conclusions of this study were as follow: First, adolescents who dropped out specialized vocational high school suffered from hard school life, disappointing lead from teachers, stereotypical lesson. And they committed misdeeds, and had psychological difficulties. Some of them kept up the good relationship with their friends, teachers, parents, some of them did not. Some of them kept up the good relationship with their friends, teachers and parents, while some of them did not. Second, they chose dropout due to various different causes. The procedures of school dropout proceeded with comparative ease. The effect of dropout prevention program is very limited. The feeling they felt at the time of school dropout varied individually. Some adolescents who dropped out specialized vocational high school were satisfied while others were stressed out, regretting their decision. Third, they lived diligently working part-time jobs or preparing General Equivalency Diploma (GED) test after dropout. They experienced positive changes in their daily lives after dropout. But sometimes they experienced various difficulties and negative changes. Most of them had their goals, and they were preparing for them. Their expectation was low that their life will succeed if they returned to school. They wanted people to understand their decision about dropout. And multiple institutions are supporting adolescents who dropped out specialized vocational high school. They need practical support : Various information, activity for career experience, counseling etc.

Protective Effect of the Ethyl Acetate-fraction of Methanol Extract of Ophiophogon japonicus on Amyloid beta Peptide-induced Cytotoxicity in PC12 Cells (소엽맥문동-에틸아세테이트 분획물의 아밀로이드 베타단백질-유발 세포독성에 대한 억제 효능)

  • Moon, Ja-Young;Kim, Eun-Sook;Choi, Soo-Jin;Kim, Jin-Ik;Choi, Nack-Shik;Lee, Kyoung;Park, Woo-Jin;Choi, Young-Whan
    • Journal of Life Science
    • /
    • v.29 no.2
    • /
    • pp.173-180
    • /
    • 2019
  • Amyloid ${\beta}$-protein ($A{\beta}$) is the principal component of senile plaques characteristic of Alzheimer's disease (AD) and elicits a toxic effect on neurons in vitro and in vivo. Many environmental factors, including antioxidants and proteoglycans, modify $A{\beta}$ toxicity. It is worthwhile to isolate novel natural compounds that could prove therapeutic for patients with AD without causing detrimental side effects. In this study, we investigated the in vitro neuroprotective effects of the ethyl acetate fraction of methanol extract of Ophiophogon japonicas (OJEA fraction). We used an MTT reduction assay to detect protective effects of the OJEA fraction on $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells. We also used a cell-based ${\beta}$-secretase assay system to investigate the inhibitory effect of the OJEA fraction on ${\beta}$-secretase activity. In addition, we performed an in vitro lipid peroxidation assay to evaluate the protective effect of the OJEA fraction against oxidative stress induced by $A{\beta}_{25-35}$ in PC12 cells. The OJEA fraction had strong protective effects against $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells and was strongly inhibitory to ${\beta}$-secretase activity, which resulted in the attenuation of $A{\beta}$ generation. In addition, the OJEA fraction significantly decreased malondialdehyde (MDA) content, which is induced by the exposure of PC12 cells to $A{\beta}_{25-35}$. Our results suggested that the OJEA fraction contained active compounds exhibiting a neuroprotective effect on $A{\beta}$ toxicity.

A Study on the Knowledge and Use of Essential Oil by People of Different Age -Focused on women in Zhejiang, China-

  • Ying, Qiaomeng;Kim, Kyeong-Ran
    • Journal of the Korea Society of Computer and Information
    • /
    • v.26 no.4
    • /
    • pp.203-211
    • /
    • 2021
  • With the advent of the age of"untact" modern people are pursuing a healthy body and mind. In order to achieve well-being, LOHAS and Wellness,people prefer to use natural affinity alternative therapies, Aromatherapy. This study focuses on women in their 20s~50s in Zhejiang Province, with the aim of investigating their knowledge and use of essential oils.The questionnaire was divided into four parts: 3 questions for general question, 11 questions for knowledge, 13 questions for use and 9 questions for satisfaction. In addition, the study was conducted using the WeChat and the Wenjuanxing Program from July 5 to August 30, 2019. Finally, a total of 617 questionnaires were analyzed. In this study, SPSS WIN 21.0 program is used for frequency analysis. The level of knowledge and satisfaction is verified by Cronbach's α. And the following analysis results were obtained by frequency analysis, descriptive statistics, Chi-squared test(χ2), one-way ANOVA on the understanding level and usege of essential oils according to age. The results were as follows. The most common characteristics of subjects were the 20s, university students, essential oil recognition was high in having experience. There is no great difference in knowledge or satisfaction depending on age. knowledge and satisfaction was moderate. The results of experience in the use of essential oils were higher among all age groups, those who in their 30s did not think that the use of essential oils would be effective. However, people in their 20s and 40s and older have unclear answers, indicating that results showed a difference. The results of the survey on usage showed that there were significant differences in period of use, place of purchase, method of purchase, purpose of use, place of use, number of use, frequency of use, body parts of use. According to the study, awareness and knowledge of essential oils vary according to age, and those in their 20s use essential oils for facial skin, and those in their 30s and older use essential oils for stress relief and body management. This study provides basic information on marketing related to diversified essential oil products according to age.

Study on the Multilevel Effects of Integrated Crisis Intervention Model for the Prevention of Elderly Suicide: Focusing on Suicidal Ideation and Depression (노인자살예방을 위한 통합적 위기개입모델 다층효과 연구: 자살생각·우울을 중심으로)

  • Kim, Eun Joo;Yook, Sung Pil
    • 한국노년학
    • /
    • v.37 no.1
    • /
    • pp.173-200
    • /
    • 2017
  • This study is designed to verify the actual effect on the prevention of the elderly suicide of the integrated crisis intervention service which has been widely provided across all local communities in Gyeonggi-province focusing on the integrated crisis intervention model developed for the prevention of elderly suicide. The integrated crisis intervention model for the local communities and its manual were developed for the prevention of elderly suicide by integrating the crisis intervention theory which contains local community's integrated system approach and the stress vulnerability theory. For the analysis of the effect, the geriatric depression and suicidal ideation scale was adopted and the data was collected as follows; The data was collected from 258 people in the first preliminary test. Then, it was collected from the secondary test of 184 people after the integrated crisis intervention service was performed for 6 months. The third collection of data was made from 124 people after 2 or 3 years later using the backward tracing method. As for the analysis, the researcher used the R Statistics computing to conduct the test equating, and the vertical scaling between measuring points. Then, the researcher conducted descriptive statistics analysis and univariate analysis of variance, and performed multi-level modeling analysis using Bayesian estimation. As a result of the study, it was found out that the integrated crisis intervention model which has been developed for the elderly suicide prevention has a statistically significant effect on the reduction of elderly suicide in terms of elderly depression and suicide ideation in the follow-up measurement after the implementation of crisis intervention rather than in the first preliminary scores. The integrated crisis intervention model for the prevention of elderly suicide was found to be effective to the extent of 0.56 for the reduction of depression and 0.39 for the reduction of suicidal ideation. However, it was found out in the backward tracing test conducted 2-3 years after the first crisis intervention that the improved values returned to its original state, thus showing that the effect of the intervention is not maintained for long. Multilevel analysis was conducted to find out the factors such as the service type(professional counseling, medication, peer counseling), characteristics of the client (sex, age), the characteristics of the counselor(age, career, major) and the interaction between the characteristics of the counselor and intervention which affect depression and suicidal ideation. It was found that only medication can significantly reduce suicidal ideation and that if the counselor's major is counseling, it significantly further reduces suicidal ideation by interacting with professional counseling. Furthermore, as the characteristics of the suicide prevention experts are found to regulate the intervention effect on elderly suicide prevention in applying integrated crisis intervention model, the primary consideration should be given to the counseling ability of these experts.

Qualitative Study on Experiences of Responding to COVID-19 of Therapists in Long-term Care Hospitals (요양병원 치료사의 코로나19 대응 경험에 대한 질적 연구)

  • Bae, Won-Jin;Park, Ju-Young
    • Journal of Korea Entertainment Industry Association
    • /
    • v.15 no.4
    • /
    • pp.337-347
    • /
    • 2021
  • This study is a qualitative study conducted to provide basic data for therapists working in long-term care hospitals to improve their countermeasure strategies for new infectious diseases and improvement of the treatment room infection management system, and to help therapists understand their infection management work. Colaizzi's phenomenological research method was applied as the research method. Telephone interviews were conducted with nine occupational therapists and physical therapists working in nursing hospitals. The contents of the interview were recorded with the consent of the study subjects, and additional confirmation was received by email. The recorded content was analyzed after transcription, and the meaning and nature of the experience coping with COVID-19 were described. The content was organized into 6 themes, 17 main meaning and 49 meaning units. In accordance with the COVID-19 situation, the infection control system has been strengthened by reinforcing infection control education in nursing hospitals, practicing infection control, and supervising infection control outside business hours. It was found that the treatment environment was changed due to the restriction of treatment activities by practicing distancing in the treatment room, adjusting rest and meal times during working hours, and strengthening infection control. In addition, the therapist's role has been expanded and the paradigm of treatment has changed, such as considering the untact intervention, and they have experienced cohort quarantine, pre-tested for COVID-19, vaccinations, and side effects from COVID-19. However, due to the infection work, the therapist's work burden is increased, and the person is experiencing fear, depression, and work stress from the spread of COVID-19. They were also aware of the need for nursing hospital care personnel support, such as guaranteeing rest after vaccination and providing infection control tools and equipment. The results of this study are expected to be used as basic data for human and physical support for the development of infectious disease response strategy programs in nursing hospital treatment rooms and for infection control in nursing hospitals.