• Title/Summary/Keyword: Lead levels

Search Result 1,203, Processing Time 0.053 seconds

The Change of Customer Participation in Service by the Development of Relationship : Application of Latent Growth Modeling (관계발전에 따른 서비스 고객참여의 변화 - 잠재성장모형의 적용 -)

  • Ahn, Jinwoo;Park, Se-Jeong
    • Management & Information Systems Review
    • /
    • v.38 no.1
    • /
    • pp.121-139
    • /
    • 2019
  • This study aims to identify the change of customer participation(CP) which is essential to the service industry as the relationship between the customer and the employee develops. The latent growth modeling analysis based on the longitudinal data is utilized to examine the pattern of the change. This is based on the fact that CP needs to be understood in the relationship and is to confirm the change in CP by the development of the relationship. Given the dynamics of the relationship, we intend to overcome the limitations of previous cross-sectional researches by revealing the trajectory of CP in the relationship through the longitudinal data. We also want to examine which variables in the relationship can facilitate changes of CP. Research has shown that CP is significantly changed with the development of the relationship when we analyzed it through latent growth modeling. This confirms that CP needs to be understood in the relationship. In addition, 'relationship proneness' variable and 'dependence to provider' variable have positive effects on the initial values of CP, but they have not been established to promote the changes of CP. Consequently, when considering the dynamics of relationships, it is important to recognize that CP is also dynamic. This study sought to get out of the cross-sectional and fragmented understanding of CP that is dynamic. Through this, we would like to propose the successful operation of the customer management program of service firms in relation to CP. This will lead to the success of service encounter where appropriate CP levels at each stage of relationship development can be achieved.

Platelets as a Source of Peripheral Aβ Production and Its Potential as a Blood-based Biomarker for Alzheimer's Disease (말초 아밀로이드 베타 원천으로서의 혈소판과 알츠하이머병의 혈액 바이오마커로서의 가능성)

  • Kang, Jae Seon;Choi, Yun-Sik
    • Journal of Life Science
    • /
    • v.30 no.12
    • /
    • pp.1118-1127
    • /
    • 2020
  • Alzheimer's disease causes progressive neuronal loss that leads to cognitive disturbances. It is not currently curable, and there is no way to stop its progression. However, since medical treatment for Alzheimer's disease is most effective in the early stages, early detection can provide the best chance for symptom management. Biomarkers for the diagnosis of Alzheimer's disease include amyloid β (Aβ) deposition, pathologic tau, and neurodegeneration. Aβ deposition and phosphorylated tau can be detected by cerebrospinal fluid (CSF) analysis or positron emission tomography (PET). However, CSF sampling is quite invasive, and PET analysis needs specialized and expensive equipment. During the last decades, blood-based biomarker analysis has been studied to develop fast and minimally invasive biomarker analysis method. And one of the remarkable findings is the involvement of platelets as a primary source of Aβ in plasma. Aβ can be transported across the blood - brain barrier, creating an equilibrium of Aβ levels between the brain and blood under normal condition. Interestingly, a number of clinical studies have unequivocally demonstrated that plasma Aβ42/Aβ40 ratios are reduced in mild cognitive impairment and Alzheimer's disease. Together, these recent findings may lead to the development of a fast and minimally invasive early diagnostic approach to Alzheimer's disease. In this review, we summarize recent advances in the biomarkers of Alzheimer's disease, especially the involvement of platelets as a source of peripheral Aβ production and its potential as a blood-based biomarker.

Riparian Vegetation Expansion Due to the Change of Rainfall Pattern and Water Level in the River (강우 발생 패턴변화와 하천 수위 변화가 하천식생 발생에 미치는 영향)

  • Kim, Won;Kim, Sinae
    • Ecology and Resilient Infrastructure
    • /
    • v.7 no.4
    • /
    • pp.238-247
    • /
    • 2020
  • This study aims to examine the causes of the rapid expansion of riparian vegetation in river channels in recent years. Accordingly, the changes in the monthly rainfall were analyzed at 19 locations over the period of 1984 to 2018. Moreover, the changes in the water levels of the target river sections of Seom River, Cheongmi River, and Naeseong River were analyzed. The results showed that rainfall increased by 30% in April and decreased by up to 49% in the May-September period since 2012. Between 2012 and 2018, when rainfall decreased, the inundation time of the floodplains of the target rivers decreased considerably. The floodplains of Seom River and Cheongmi River were not inundated since 2012 and 2013, respectively. In the case of Naeseong River, the inundation time of the low-water channel drastically decreased since 2013, and there was no inundation in 2015. Consequently, riparian vegetation settled rapidly on the floodplain without any disturbance and continued to expand. The settling and expansion of riparian vegetation reduce the flood capacity of the river channel and can also lead to the loss of the water ecosystem due to terrestrialization.

Effects of Working Competency of Local Child Centers on the Quality of Service for Children: The Mediation Effect of Self-Efficiency (지역아동센터 종사자의 업무 역량이 아동서비스의 질에 미치는 영향: 자기효능감의 매개효과)

  • Park, Woon-ju
    • The Journal of the Korea Contents Association
    • /
    • v.21 no.1
    • /
    • pp.590-602
    • /
    • 2021
  • This study was originated from the idea that it would be important for caring service of community children center to be positioned as the institution to strengthen the public nature and provide quality care services to children. In particular, competencies of the employees in community children centers play an important role and the quality of children care services is the crucial evaluation parameter for those institutions. The objectives of this study are to investigate the effects of the competency levels of the employees in community children centers on the service quality to children and to verify the mediated effect of self-efficacy on their service quality to children. With respect to the data analysis methods, hierarchical regression analysis was performed. Barron & Kenny's method was used to understand the mediated effect of self-efficacy. Also, Sobel test was performed to investigate the significance of mediated effect of self-efficacy. The study results are, first, the service quality to children might be differed by the level of competencies of the employees in community children centers; and second, partial mediated effect of self-efficacy was found between their competencies and service quality to children. These results implicate that service quality to children can be improved by strengthening competencies of the employees in community children centers and enhancing their self-efficacy. It is necessary to try to improve the service quality by enhancing competencies and self-efficacy of the employees in community children centers, which will lead those institutions to play a crucial role in the caring services.

Residue and risk assessment of veterinary antibiotics in manure-based composts and agricultural soils (가축분뇨 유래 퇴비 및 농경지 중 축산용 항생제의 잔류 및 위해성 평가)

  • Paik, Min-Kyoung;Ryu, Song-Hee;Kim, Sung-Chul;Hong, Young-Kyu;Kim, Jin-Wook;Kim, Jeong-Gyu;Kwon, Oh-Kyung
    • Journal of Applied Biological Chemistry
    • /
    • v.64 no.2
    • /
    • pp.177-184
    • /
    • 2021
  • While veterinary antibiotics are used only in a part of the dose administered, the rest are excreted as urine or feces. Residual antibiotics enter the adjacent agricultural environments by spraying manure-based composts on farmlands and lead to secondary pollution. Therefore, it is necessary to develop the technique for post management such as regulatory levels of antibiotics in the agricultural environments. This study was conducted to compare by different matrices the amount of residual antibiotics such as tetracyclines and sulfonamides, which are known to be frequently used in Korea and to practice risk assessment by different antibiotics in soils before and after application of composts. Pre-treatment with modified typical method using buffer and solid phase extraction showed the recovery of composts and soils was more than 70% at ppb level and the limits of detection were 0.13-0.46 and 0.05-0.25 ㎍/kg, respectively. Analysis of manure-based composts revealed concentrations from 5.38 to 196.0 ㎍/kg for tetracyclines, from below the detection of limit (BDL) to 259.0 ㎍/kg for sulfonamides. In case of agricultural soils, residual concentrations of selected veterinary antibiotics were ranged 0.30-53.3 ㎍/kg, BDL-4.16 ㎍/kg respectively and the concentration level of tetracyclines, which had higher soil distribution coefficient (Kd) values, was higher than that of sulfonamides. There was a difference in human risk assessment by different antibiotics in soil before and after application of composts. But, it was indicated that detection values of all of 5 antibiotics were very safe on the basis that Hazard Quotient was safe below 1.

The Convergence Factors of Nurses' Character on the Burnout: Focused on the Mediating Effects of Resilience (병원간호사의 임상간호인성이 소진에 미치는 융합적 영향요인: 회복탄력성의 매개효과 중심으로)

  • Ryu, Jeong-Lim;Ju, Jeong-Suk;Kim, Shin-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.22 no.1
    • /
    • pp.354-362
    • /
    • 2021
  • The purpose of this study was to test the mediating effect of resilience on the relationship between nurses' character and burnout. Participants were 118 clinical nurses in general hospitals located in J province. From August 1st to 31st, 2020, a questionnaire scale was used to collect the data. Data were analyzed using an independent t-test, one-way ANOVA, Pearson's correlation coefficients, linear regression, and the Sobel test. The study revealed that there was a significant positive relationship between character and resilience (r=.63, p<.001) and a negative correlation with burnout (r=-.48, p<.001). Also, resilience had a partial mediating effect on character and burnout. These findings indicate that it will be more effective to develop and apply programs that promote character and resilience to reduce burnout among clinical nurses. The conclusion that resilience affects the burnout of nurses can be used for formulating personal and organizational Human Resource Management strategies and can lead to positive protective results at the intra-personal and environmental levels.

Investigation of Hazardous materials from domestic and Chinese dried-ear mushroom (국내산 및 중국산 건조 목이(Auricularia auricula-judae)의 유해물질 조사)

  • Jang, Eun-Kyoung;Jeong, Sang-Wook;Choi, Seul-Gi;Kim, Yu-Seon;Lee, Won-Ho;Ban, Seung-Eon
    • Journal of Mushroom
    • /
    • v.18 no.4
    • /
    • pp.387-392
    • /
    • 2020
  • Eight dried ear mushroom products (three domestic and five Chinese products) distributed in Korea were analyzed for 321 residual pesticides, 7 heavy metals, and 3 types of radioactivity. Residual pesticides in the domestic products were not detected. However, chlorpyrifos, isoprocarb, mepiquat chloride, and carbendazim were detected in four Chinese products, all of which were below the allowable residual limit. Among the detected pesticide ingredients, only the residue for mepiquat chloride has been established to be present in ear mushrooms. In the heavy metal test, trace amounts of heavy metals were detected in all samples. However, none of the samples exceeded the allowable residual limits, except for one domestic sample that exceeded the standard value of 0.3 mg/kg for lead. Radioactivity tests confirmed that levels were below the minimal detectable activity value in all samples.

A Study on Seismic Fragility of PSC Bridge Considering Aging and Retrofit Effects (PSC 교량의 노후도 및 FRP 보강 효과를 고려한 지진취약도 분석)

  • An, Hyojoon;Lee, Jong-Han
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.24 no.6
    • /
    • pp.34-41
    • /
    • 2020
  • In recent years, magnitude and frequency of earthquakes have increased in Korea. Damage to a bridge, which is one of the main infrastructures, can directly lead to considerable loss of human lives. Therefore, engineers need to evaluate the seismic fragility of the structure and prepare for the possible seismic damage. In particular, the number of aging bridges over 30 years of service increases, and thus the seismic analysis and fragility requires accounting for the aging and retrofit effects on the bridge. In this study, the nonlinear static and dynamic analyses were performed to evaluate the effects of the aging and FRP retrofit on a PSC bridge. The aging and FRP retrofit were applied to piers that dominate the response of the bridge during earthquakes. The maximum displacement of the bridge increased due to the aging of the pier but decreased when FRP retrofit applied to the aged pier. In addition, seismic fragility analysis was performed to evaluate the seismic behavior of the bridge combined with the seismic performance of the pier. Compared with the aged bridge, the FRP retrofit bridge showed a decrease in the seismic fragility in all levels of damage. The reduction of the seismic fragility in the FRP bridge was prominent as the value of PGA and level of damage increased.

Effects of Participation in Non-face-to-face Daily Science Class on Elementary School Students' Perception of Science and Scientific Competency (비대면 생활과학교실 참여가 초등학생들의 과학기술에 대한 인식 및 과학적 역량에 미치는 영향)

  • Choi, Kyoulee;Oh, Yoonjeong;Lee, Sun-Mi;Zhang, Mi-Hwa;Lee, Mihyoung;Cho, Kyung-suk
    • Journal of Science Education
    • /
    • v.46 no.1
    • /
    • pp.40-52
    • /
    • 2022
  • Daily science classes, which have been continued as part of the spread of participatory science culture, has taken the lead in popularizing science as an effective out-of-school experiential and research activity. However, due to the recent COVID-19 situation, daily science classes have also become an environment in which there is no choice but to switch to non-face-to-face or to combine face-to-face and non-face-to-face education. Therefore, in this study, we examine how elementary school students participating in the non-face-to-face daily science class program change their usual fields of interest, perception of science and technology, interest about science, and scientific competency. In addition, the educational effectiveness of the non-face-to-face daily science class improved by comparing the differences in perceptions of students and parents, and future operation plans were sought. As a result of the study, after participating in the non-face-to-face daily science class program, students' interest in science and technology development, future technology, environmental pollution, and social media increased, and their interest in games decreased. Also, students' interest in science and technology activities, interest in science, and scientific competency also increased. This shows that non-face-to-face daily science class education is effective. Therefore, it was suggested that it is necessary to diversify the learning topics and content levels of the daily science class program, to expand the opportunities of non-face-to-face science education for underprivileged learners, and to develop and share science content using the latest media.

Analysis of Digital Twin Technology Trends Related to Geoscience and Mineral Resources after the Korean New Deal Policy in 2020 (2020년 한국판 뉴딜 정책 이후 지질자원 분야 디지털 트윈 기술개발 동향 분석)

  • Ahn, Eun-Young
    • Economic and Environmental Geology
    • /
    • v.54 no.6
    • /
    • pp.659-670
    • /
    • 2021
  • In this study, we analyzed changes in policies after the Korean New Deal Policy in 2020, metaverse and 6th generation communication technology. In the research and development of geoscience and mineral resources, we emphasized on the connection between smart cities and digital twins by focusing on the linkage of the real world and geo-information. Further, we examined trends in developing digital twins after the Korean New Deal Policy in 2020 that focused on three-dimensional visualization technology, the first stage in implementing digital twins, and real-time monitoring technology of underground information, the second implementing stage. As results of this study, we emphasized on the efforts to provide accurate underground information based on geology, groundwater and geo-environment and to analyze and predict near-real-time levels of available underground information to the industry, local governments and the central governments. Research and development that integrate the fields of geology, environment, and information is required to lead national digital twin policies and smart city policies owing to the acceleration of the digital economy in Korea and globally during the post-Corona era.