• Title/Summary/Keyword: studies on turnover

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Expression, Refolding, and Characterization of the Proteolytic Domain of Human Bone Morphogenetic Protein 1 (뼈형성 단백질(Bone Morphogenetic Protein 1)의 단백질 분해 부위의 발현 및 특성 연구)

  • ;Daihung Do
    • Journal of Life Science
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    • v.10 no.2
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    • pp.218-227
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    • 2000
  • Bone morphogenetic protein 1 (BMP-1) is part of a complex capable of inducing ectopic bone formation in mammals. Studies on TGF-β1 processing and Drosophila dorsal-ventral patterning have focused attention on BMP-1 as important in mediating the biological activity of this bone inducing complex. Herein, the bacterial expression, refolding, purification, and initial characterization of the BMP-1 proteolytic domain (BPD) are described. A semi-quantitative fluorescence-based thin layer chromatography assay was developed to assist in rapidly screening for optimal renaturation conditions. According to a preliminary screen for optimal conditions for the refolding of BPD , a detectable proteolytic activity against a high turnover substrate for astacin, a homologous protease from crayfish was observed. The conditions identified have allowed the expression of sufficient amounts of BPD for the characterization of the protein. Its proteolytic activity exhibits the same cleavage specificity as astacin against seven substrates that were previously synthesized for studying astacin. Furthermore, this activity is inhibited by the metal chelator 1,10-phenanthroline but not by its analogue 1,7-phenanthroline. The collagenase inhibitor Pro-Leu-Gly hydroxamate was found to inhibit both astacin and BPD activity. The results presented in this paper argue that BMP-1 does in fact possess an intrinsic proteolytic activity.

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Effect of Tea Polyphenols on Conversion of Nicotine to Cotinine

  • Lee, Dong-Hee;Kim, Ha-Won
    • Biomolecules & Therapeutics
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    • v.11 no.4
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    • pp.238-244
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    • 2003
  • Nicotine is one of the major hazardous components in cigarettc smoke. Nicotine deals a harmful effect to smokers and passive smokers due to its rapid conversion to various carcinogenic metabolites. Nitrosamine-4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is believed to cause lung cancers among the nicotine-derived carcinogens. Recent studies report that NNK synthesis can be inhibited by the metabolism pathway to produce a stable metabolite cotinine from nicotine. Tea polyphenols have been known to contain factors to prevent cancers and to retard progression of cancers. This study aims to correlate tea polyphenol's potential for cancer prevention with an accelerated formation of cotinine. The conversion from nicotine to cotinine in the presence of tea extracts or three polyphenols (Catechin, epicatechin gallate, epigallocatechin gallate) was measured in established cell lines and in Xenopus oocytes. Among three lines of cell used, PLC/PRF5 and HEK293 cells showed a fast turnover from nicotine to cotinine while HepG2 cell line showed a marginal difference between groups treated and non-treated with tea polyphenols. When Xenopus oocytes were microinjected with nicotine, tea polyphenols appear to accelerate the conversion of nicotine to cotinine. Among the polyphenols tested in this study, (+)-catechin showed the best efficiency overall in accelerating conversion from nicotine to cotinine both in the cell lines and in the oocytes. In summary, the present study indicated that tea polyphenols have a positive effect on conversion of nicotine to cotinine.

The Impact of Corporate Image on Employees' Alturistic Behavior in Franchise Industry: Mediating Role of Organizational Trust and Affective Commitment (프랜차이즈 기업이미지가 종업원의 이타적 행동에 미치는 영향: 조직신뢰와 정서적 몰입의 매개역할)

  • Hur, Soon-Beom;An, Dae-Sun;Cho, Hye-Duk
    • The Korean Journal of Franchise Management
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    • v.8 no.4
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    • pp.33-43
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    • 2017
  • Purpose - Previous studies about corporate image generally explore how corporate image affects a company's effectiveness from the consumer view. However this study attempts to explore the impacts of corporate image (reliability, friendly, corporate social responsibility, and innovation) on employees' altruistic behaviors in the franchise industry context. This study also examine whether organizational trust and affective commitment play a mediating role in the relationship between corporate image and employees' altruistic behaviors. The authors developed several hypotheses to achieve these purposes. Research design, data, and methodology - The data were collected from employees in food-service franchise companies located in Seoul, Korea. Among a total of 363 questionnaires distributed, 294(response rate of 81%) questionnaires were returned. After excluding 18 invalid respondent questionnaires, 276 valid questionnaires(response rate of 76%) were coded and analyzed using frequency, confirmatory factor analysis, correlations analysis, and structural equation modeling with SPSS 21 and SmartPLS 3.0. Result - The findings of the study are as follows: First, friendly, CSR, and innovation had positive effects on organizational trust, but reliability did not have a significant effect on organizational trust. Second, reliability and friendly of corporate image had positive effects on affective commitment, but CSR and innovation did have a significant effect on affective commitment. Third, organizational trust and affective commitment had positive effects on employees' altruistic behaviors. Conclusions - The aim of this study is to investigate the franchise corporate image as a significant influencing factor of employees' altruistic behaviors. The data were collected from only employees from franchising companies. The findings might vary from position to position. Future studies need to collect and compare data from managers. Future studies need to consider other variables that affect employees' altruistic behaviors. For example, leadership and market orientation might influence employees' attitude and behaviors. Also, future research should include other variables and it may have limitations in sample representative because of sampling franchise corporate in Seoul. Future studies will include franchise corporate all over the country. Future studies can also consider other variables (e.g., job performance and turnover intentions) to measure employee performance at the level of individuals and identify the impact of employee performance on business performance at the level of corporate.

A Study of the Arbitration to the Rural Land Contract Disputes in China (중국 농지임대차분쟁의 중재에 관한 고찰)

  • Kim, Yong Kil
    • Journal of Arbitration Studies
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    • v.21 no.3
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    • pp.137-163
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    • 2011
  • The Law of the People's Republic of China on the Mediation and Arbitration of Rural Land Contract Disputes, which was adopted at the 9th session of the Standing Committee of the 11th National People's Congress of the People's Republic of China on June 27, 2009, is hereby promulgated and shall come into force as of January 1, 2010. This Law is enacted with a view to impartially and timely settling the disputes over contracted management of rural land, maintaining the legitimate rights and interests of the parties concerned and promoting the rural economic development and social stability. The mediation and arbitration of disputes over contracted management of rural land shall be governed by this Law. The disputes over the contracted management of rural land include: 1) disputes arising from the conclusion, fulfillment, modification, cancellation and termination of rural land contracts; 2) disputes arising from the sub-contract, lease, interchange, transfer, holding of shares and other means of turnover of contracted management rights to rural land ; 3) disputes arising from the withdrawal and adjustment of the contracted land; 4) disputes arising from the confirmation of contracted management rights to rural land; 5) disputes arising from impairment to the contracted management rights to rural land; and 6) other disputes over contracted management of rural land as prescribed in law and regulations. The disputes arising from requisition of collectively owned land and the compensations therefor do not fall within the scope of acceptance by the rural land contract arbitration commission, they may be settled by means of administrative reconsideration or lawsuits. In the case of disputes over the contracted management of rural land, the parties may make reconciliation by themselves or may request mediation by the villagers' committee, people's government of the township (town), etc. This study analyzed each process and the main issues on the point of the Mediation and Arbitration of Rural Land Contract Disputes.

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Histological analysis on tissues around orthodontically intruded maxillary molars using temporary anchorage devices: A case report

  • Hui-Chen Tsai;Julia Yu-Fong Chang;Chia-Chun Tu;Chung-Chen Jane Yao
    • The korean journal of orthodontics
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    • v.53 no.2
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    • pp.125-136
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    • 2023
  • Before progress was recently made in the application of temporary anchorage devices (TADs) in bio-mechanical design, orthodontists were rarely able to intrude molars to reduce upper posterior dental height (UPDH). However, TADs are now widely used to intrude molars to flatten the occlusal plane or induce counterclockwise rotation of the mandible. Previous studies involving clinical or animal histological evaluation on changes in periodontal conditions after molar intrusion have been reported, however, studies involving human histology are scarce. This case was a Class I malocclusion with a high mandibular plane angle. Upper molar intrusion with TADs was performed to reduce UPDH, which led to counterclockwise rotation of the mandible. After 5 months of upper molar intrusion, shortened clinical crowns were noticed, which caused difficulties in oral hygiene and hindered orthodontic tooth movement. The mid-treatment cone-beam computed tomography revealed redundant bone physically interfering with buccal attachment and osseous resective surgeries were followed. During the surgeries, bilateral mini screws were removed and bulging alveolar bone and gingiva were harvested for biopsy. Histological examination revealed bacterial colonies at the bottom of the sulcus. Infiltration of chronic inflammatory cells underneath the non-keratinized sulcular epithelium was noted, with abundant capillaries being filled with red blood cells. Proximal alveolar bone facing the bottom of the gingival sulcus exhibited active bone remodeling and woven bone formation with plump osteocytes in the lacunae. On the other hand, buccal alveolar bone exhibited lamination, indicating slow bone turnover in the lateral region.

Randomized, Double-blind, Placebo-controlled Trial of the Effects of Polycan, β-glucan Originating from Aureobasidium Pullulans, on Bone Biomarkers in Healthy Women

  • Kim, Jong Dae;Park, Mi Yeon;Kim, Joo Wan;Kim, Ki Young;Cho, Hyung Rae;Choi, In Soon;Choi, Jae Suk;Ku, Sae Kwang;Park, Soo-Jin
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.29 no.4
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    • pp.330-336
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    • 2015
  • Polycan originating from Aureobasidium pullulans is mostly composed of β-1, 3/1, 6 glucans and possesses an anti-osteoporotic effect. We conducted a randomized, double-blind, placebo-controlled trial to examine the efficacy and safety of the polycan on bone biochemical markers in healthy perimenopausal women. Sixty subjects were randomly allocated to 2 groups-group 1 received 400 mg of polycan and group 2 received placebo-these were administered once daily for 28 days. Fasting blood and urine samples were collected at baseline and 4 weeks after treatment. The primary outcome was change in osteocalcin (OSC) and bone-specific alkaline phosphatase (BALP). Changes in calcium (Ca), phosphorus (P), C-telopeptide of collagen cross-links (CTx), N-telopeptide of collagen cross-links (NTx), and deoxypyridinoline (DPYR) were the secondary outcomes. A safety assessment was performed using adverse event (AE) and laboratory data. After 4 weeks of polycan treatment, OSC, DPYR, and BALP levels changed (P < 0.05) significantly from baseline in both groups. However, no significant differences were observed in any markers between the 2 groups, except for P (P < 0.05). Interestingly, group 2 showed a significant increase in CTx (65.2%, P < 0.05), while CTx in group 1 slightly increased (17.2%). Both groups showed no significant differences in AE. Although 4 weeks of polycan treatment did not have a statistically significant effect on bone metabolism biomarkers, increases in CTx were modestly inhibited by polycan. Further studies in a large population and longer treatment periods are needed to confirm the effect of polycan on bone turnover.

Theoretical Examination of the Pay-for-Performance Practice: Case of a Shipbuilding Company

  • Jun, Gyung-Ju
    • Journal of Navigation and Port Research
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    • v.37 no.5
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    • pp.471-480
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    • 2013
  • Pay-for-performance plans are some of widely used human resource practices in many firms, including shipbuilding, for productivity and motivational improvement purposes. Such plans play an important role in industries that are highly labor-intensive, and where effective management of human resources is critical to business operations, such as the shipbuilding industry. Those practices can have large impact on employee performance and ultimately company competitiveness. Research studies that show how such incentive plans improve productivity and reported pattern of adoption by firms have spurred the use and adoption in many firms. However, there are also researchers who point out that there are negative consequences to using incentive plans. Therefore it is important for companies to carefully consider the practices they use. In this paper, I discuss research findings that support the practices and critical viewpoints related to pay-for-performance plans. Research findings from Korean literature are, then, discussed. The shipbuilding industry is chosen because proper human resource management is critical in reducing turnover and increasing employee satisfaction. Through a shipbuilding company case, problems related to using pay-for-performance incentive plans and how they affect work-related issues of employee morale, cooperation, and teamwork will be discussed. While positive aspects have been emphasized to drive greater adoption among firms, the resulting consequences of the pay plans need to be seriously considered and improvements upon the plans made by firms. Improvement suggestions are discussed in the conclusions and implications.

A Study on the Insolvency Prediction Model for Korean Shipping Companies

  • Myoung-Hee Kim
    • Journal of Navigation and Port Research
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    • v.48 no.2
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    • pp.109-115
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    • 2024
  • To develop a shipping company insolvency prediction model, we sampled shipping companies that closed between 2005 and 2023. In addition, a closed company and a normal company with similar asset size were selected as a paired sample. For this study, data of a total of 82 companies, including 42 closed companies and 42 general companies, were obtained. These data were randomly divided into a training set (2/3 of data) and a testing set (1/3 of data). Training data were used to develop the model while test data were used to measure the accuracy of the model. In this study, a prediction model for Korean shipping insolvency was developed using financial ratio variables frequently used in previous studies. First, using the LASSO technique, main variables out of 24 independent variables were reduced to 9. Next, we set insolvent companies to 1 and normal companies to 0 and fitted logistic regression, LDA and QDA model. As a result, the accuracy of the prediction model was 82.14% for the QDA model, 78.57% for the logistic regression model, and 75.00% for the LDA model. In addition, variables 'Current ratio', 'Interest expenses to sales', 'Total assets turnover', and 'Operating income to sales' were analyzed as major variables affecting corporate insolvency.

Critical Role of Glu175 on Stability and Folding of Bacterial Luciferase: Stopped-flow Fluorescence Study

  • Shirazy, Najmeh Hadizadeh;Ranjbar, Bijan;Hosseinkhani, Saman;Khalifeh, Khosrow;Madvar, Ali Riahi;Naderi-Manesh, Hossein
    • BMB Reports
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    • v.40 no.4
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    • pp.453-458
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    • 2007
  • Bacterial luciferase is a heterodimeric enzyme, which catalyzes the light emission reaction, utilizing reduced FMN (FMNH2), a long chain aliphatic aldehyde and $O_2$, to produce green-blue light. This enzyme can be readily classed as slow or fast decay based on their rate of luminescence decay in a single turnover. Mutation of Glu175 in $\alpha$ subunit to Gly converted slow decay Xenorhabdus Luminescence luciferase to fast decay one. The following studies revealed that changing the luciferase flexibility and lake of Glu-flavin interactions are responsible for the unusual kinetic properties of mutant enzyme. Optical and thermodynamics studies have caused a decrease in free energy and anisotropy of mutant enzyme. Moreover, the role of Glu175 in transition state of folding pathway by use of stopped-flow fluorescence technique has been studied which suggesting that Glu175 is not involved in transition state of folding and appears as surface residue of the nucleus or as a member of one of a few alternative folding nuclei. These results suggest that mutation of Glu175 to Gly extended the structure of Xenorhabdus Luminescence luciferase, locally.

A study on self-esteem and turnover intention according to dental hygienists in part of Jeonbuk area (전북지역 일부 치과위생사의 자아존중감과 이직의도에 관한 연구)

  • Kim, Jeong-Suk;Won, Young-Soon;Park, So-Young
    • Journal of Korean society of Dental Hygiene
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    • v.12 no.2
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    • pp.307-315
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    • 2012
  • Objectives : This study is to make basic materials for an effective human resource management plan by understanding relationship between self-esteem and intention of transfer of dental hygienists who are working in dental diagnostic institutions and to contribute to human resource program development for promoting development into a dental hygienic profession. Methods : This survey was carried out for dental hygienists who are engaging in dental diagnostic institutions in part of Cheonbuk Area by survey researchers for 10 days from September 14 to September 24, 2011 by visiting dental clinics after respondents replied to a questionnaire after listening to explanations of study purposes. Total 210 copies of questionnaire were retrieved and 201 copies were used as materials for the final analysis excluding 9 copies with insincere replies. Results : 1. The total average grade for self-esteem of study objects was 32.83(${\pm}3.08$) points. The total average of intention of transfer was found to be 32.91(${\pm}7.50$) points. 2. Self-esteem by satisfaction on the current workplaces was shown to be high with 'very satisfactory'(p=0.028), which has significant difference statistically (p<0.05). 3. In the intention of transfer by general characteristics, 20-25 years ($35.15{\pm}7.17$) was higher than over 40 years old ($23.44{\pm}3.47$) by age to show significant difference statistically (p=0.000). As for married status, single ($34.42{\pm}6.64$) was found to have higher intention of transfer than married ($30.28{\pm}8.11$), which showed significant difference statistically (p=0.018). As for the education background, 3 year course college graduates ($33.49{\pm}7.25$) showed more intention of transfer than over undergraduate students ($22.75{\pm}9.43$) to show significance statistically (p=0.002) and in the working years 1~3 years ($34.40{\pm}7.07$) was found to have more intention of transfer than over 10 years ($25.13{\pm}5.08$) to be significant statistically (p=0.000). The annual income less than 25 million won ($34.10{\pm}6.54$) showed more intention of transfer than over 40 million won ($21.00{\pm}0.00$) (p=0.000). 4. Intention of transfer by satisfaction of current workplaces was found to be high in 'very unsatisfactory', which showed significant difference statistically (p<0.001). 5. Pure correlation between self-esteem and intention of transfer came into existence and intention of transfer was found to be higher as self-esteem is higher. Conclusions : Through results as above, intention of transfer of dental hygienists was found to be higher as self-esteem is higher. Various follow-up studies which are to perform empirical verification by analyzing various factors which can affect intention of transfer based on this and using them as control variables are thought to be tried.