• Asia pacific journal of information systems
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• v.33 no.2
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• pp.367-388
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• 2023

This study aimed to examine the factors of information-sharing intention on social networking sites (SNSs) by integrating the perspectives of the institution-based trust, social presence, and theory of reasoned action (TRA). An empirical survey was conducted and 364 valid respondents were collected from Facebook (FB) users in Taiwan. These data were analyzed against the research model using the partial least squares (PLS) structural equation modeling. The findings revealed that situational normality and structural assurance have a positive influenced user trust in SNSs which in turn increased their information-sharing attitudes. Furthermore, the subjective norms, user information-sharing attitudes and social presence of the SNSs were shown to have a positive influenced on user information sharing intention. Finally, this study provided several important theoretical and practical implications to understand factors affecting information-sharing intention on SNSs.

• Journal of Service Research and Studies
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• v.9 no.2
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• pp.55-76
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• 2019

This study conducted empirical analyses to investigate the factors affecting the intention to use smart home services. Based on the previous relevant studies, the characteristics of smart home service were found to influence on the intention to use smart home service, and four variables(ubiquitous connectivity, reliability, context awareness, and security) concerning the service characteristics could be derived. And referring to the technology acceptance model(TAM), the updated TAM, IS success model, and the theory of reasoned action(TRA), three variables such as perceived ease of use, perceived usefulness and subjective norm were also likely to affect the intention to use smart home service, and the user innovativeness was inferred to play a role of moderating variable. In order to examine the research model and the hypotheses which could describe the relationship of the above mentioned variables, this study surveyed 447 people who were currently using or would use the smart home services, and then tested the hypotheses for 436 valid responses. The results of hypotheses testing showed that reliability, context awareness, and security have a significant effect on perceived usefulness and on perceived ease of use. However, it was found that ubiquitous connectivity significantly affected perceived usefulness but did not affect perceived ease of use. And perceived ease of use, perceived usefulness and subjective norm had significant effect on the intention to use smart home services. Also, user innovativeness as moderating variable was found to significantly influence on the magnitude of the relationship between ubiquitous connectivity and perceived usefulness and on that between reliability and perceived ease of use. This can be interpreted as the findings implying that innovative smart home-service users are likely to feel the smart home-services more useful than ordinary users when the degree of ubiquitous connectivity is higher, and are likely to perceive the use of smart home-services to be easier than ordinary ones when the degree of reliability is higher.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.26-34
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• 2009

Porcine embryonic stem (ES) cells have a great potential as tools for transgenic animal production and studies of regulation of differentiation genes. Although several studies showed successful derivation of porcine ES-like cells, these cells were not maintained long-term in culture. Therefore, this study was conducted to establish porcine pluripotent ES-like cells using in vivo fertilized embryos and to maintain these cells in long term culture. Porcine ES-like cells from in vivo embryos obtained by immunosurgery or whole explant culture were successfully cultured for over 56 passages. Morphology of porcine ES-like cells was flat-shaped with a monolayer type colony. These cells stained for alkaline phosphatase throughout the culture. Furthermore, porcine ES-like cells reacted with antibodies against Oct-4, SSEA-1, SSEA-4, Tra-1-60, and Tra-1-81, which are typical markers of undifferentiated stem cells. To characterize the ability of porcine ES-like cells to differentiate into three germ layers, embryoid body formation was induced. After plating of these cells, porcine ES-like cells were spontaneously differentiated into various cell types of all three germ layers. In addition, porcine ES-like cells were successfully derived from IVF blastocysts in media containing human recombinant basic fibroblast growth factor.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.4
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• pp.261-271
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• 2004

Objective: This study was performed to evaluate the possibility of prolonged culture of human embryonic stem cells (hESC; SNUhES2) on human amniotic fluid cells (hAFC), which had been storaged after karyotyping. Method: The hAFC was prepared for feeder layer in the presence of Chang's medium and STO medium (90% DMEM, 10% FBS) at $37^{circ}C$ in a 5% $CO_2$ in air atmosphere. Prior to use as a feeder layer, hAFC was mitotically inactivated by mitomycin C. The hESCs on hAFC were passaged mechanically every seven days with ES culture medium (80% DMEM/F12, 20% SR, bFGF). Results: The hAFC feeder layer support the growth of undifferentiated state of SNUhES2 for at least 59 passages thus far. SNUhES2 colonies on hAFC feeder appeared slightly angular and flatter shape as compared with circular and thicker colonies observed with STO feeder layer and showed higher level with complete undifferentiation in seven days. Like hESC cultured on STO feeders, SNUhES2 grown on hAFC expressed normal karyotype, positive for alkaline phosphatase activity, high telomerase activity, Oct-4, SSEA-3, SSEA-4, Tra-1-60 and Tra-1-81 and formed embryoid bodies (EBs). Conclusion: The hAFC supports undifferentiated growth of hESC. Therefore, these results may help to provide a clinically practicable method for expansion of hESC for cell therapies.

• Development and Reproduction
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• v.11 no.2
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• pp.85-96
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• 2007

Mesenchymal stem cells (MSC) are promising candidates for cell-based therapies. One major obstacle for their clinical use is the unsafety of fetal bovine serum (FBS), which is a crucial part of all media currently used for the culture of MSC. We investigated the effect of human cord serum (HCS) on the growth response, mRNA and protein expressions of human amnion-derived stem cells (HAM). HAM were isolated from the amnion after a Caesarean section and cultured in DMEM supplemented with 10% FBS, 5% HCS or 10% HCS. During culture, their biological characteristics at earlier and later passages were analyzed using RT-PCR and immunocytochemistry. Regardless of serum sources, HAM showed the prominent expression of Oct-4, Rex-1, SCF, FGF-5, BMP-4, nestin, GATA-4, NCAM and HLA ABC genes. The expression profile was observed even at later passages. Similarly, HAM cultured in either FBS or HCS exhibited the distinct protein expression of collagen I, II, III and XII, fibronectin, $\alpha$-smooth muscle actin, vimentin, CK18, CD54, FSP, TRA-1-60, SSEA-3, -4 and HLA ABC. However, desmin expression was only observed in HAM cultured in medium supplemented with FBS and vWF expression was only found in HAM cultured in medium supplemented with HCS. Overall pattern of gene and protein expression of HAM was typical of known adult stem cells such as bone marrow-derived MSC. In conclusion, HCS could be as effective as FBS for the culture of HAM.

• Food Science of Animal Resources
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• v.26 no.3
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• pp.402-409
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• 2006

Although microorganisms are, in fact, the most diverse and abundant type of organism on Earth, the ecological functions of microbial populations remains poorly understood. A variety of bacteria including marine Vibrios encounter numerous ecological challenges, such as UV light, predation, competition, and seasonal variations in seawater including pH, salinity, nutrient levels, temperature and so forth. In order to survive and proliferate under variable conditions, they have to develop elaborate means of communication to meet the challenges to which they are exposed. In bacteria, a range of biological functions have recently been found to be regulated by a population density-dependent cell-cell signaling mechanism known as quorum-sensing (QS). In other words, bacterial cells sense population density by monitoring the presence of self-produced extracellular autoinducers (AI). N-acylhomoserine lactone (AHL)-dependent quorum-sensing was first discovered in two luminescent marine bacteria, Vibrio fischeri and Vibrio harveyi. The LuxI/R system of V. fischeriis the paradigm of Gram-negative quorum-sensing systems. At high population density, the accumulated signalstrigger the expression of target genes and thereby initiate a new set of biological activities. Several QS systems have been identified so far. Among them, an AHL-dependent QS system has been found to control biofilm formation in several bacterial species, including Pseudomonas aeruginosa, Aeromonas hydrophila, Burkholderia cepacia, and Serratia liquefaciens. Bacterial biofilm is a structured community of bacterial cells enclosed in a self-produced polymeric matrix that adheres to an inert or living surface. Extracellular signal molecules have been implicated in biofilm formation. Agrobacterium tumefaciens strain NT1(traR, tra::lacZ749) and Chromobacterium violaceum strain CV026 are used as biosensors to detect AHL signals. Quorum sensing in lactic acid bacteria involves peptides that are directly sensed by membrane-located histidine kinases, after which the signal is transmitted to an intracellular regulator. In the nisin autoregulation process in Lactococcus lactis, the NisK protein acts as the sensor for nisin, and NisR protein as the response regulator activatingthe transcription of target genes. For control over growth and survival in bacterial communities, various strategies need to be developed by which receptors of the signal molecules are interfered with or the synthesis and release of the molecules is controlled. However, much is still unknown about the metabolic processes involved in such signal transduction and whether or not various foods and food ingredients may affect communication between spoilage or pathogenic bacteria. In five to ten years, we will be able to discover new signal molecules, some of which may have applications in food preservation to inhibit the growth of pathogens on foods.

• Journal of the Korean Society for information Management
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• v.40 no.1
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• pp.1-21
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• 2023

This study specifically reviewed the performance of the ranking schemes as an efficient feature selection method for text classification. Until now, feature ranking schemes are mostly based on document frequency, and relatively few cases have used the term frequency. Therefore, the performance of single ranking metrics using term frequency and document frequency individually was examined as a feature selection method for text classification, and then the performance of combination ranking schemes using both was reviewed. Specifically, a classification experiment was conducted in an environment using two data sets (Reuters-21578, 20NG) and five classifiers (SVM, NB, ROC, TRA, RNN), and to secure the reliability of the results, 5-Fold cross-validation and t-test were applied. As a result, as a single ranking scheme, the document frequency-based single ranking metric (chi) showed good performance overall. In addition, it was found that there was no significant difference between the highest-performance single ranking and the combination ranking schemes. Therefore, in an environment where sufficient learning documents can be secured in text classification, it is more efficient to use a single ranking metric (chi) based on document frequency as a feature selection method.

• Journal of Intelligence and Information Systems
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• v.29 no.4
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• pp.111-127
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• 2023

This study is a study on user perception of ChatGPT use. The goal of this study is to analyze the relationship between user policy expectations and user innovativeness on ChatGPT technology acceptance and intention to use using variables of TRA (Theory of Reasoned Action). The impact of policy expectations and user innovativeness on the intention to use by mediating usefulness and hedonic motivation, and the impact of subjective norms on the usefulness and intention to use were analyzed by dividing them into the MZ generation and the non-MZ generation. It was verified whether there was a moderating effect on the effect of age differences on usefulness by interacting with policy expectations. An online survey was conducted on 300 ChatGPT users using PLS (Partial Least Square) structural equations and SPSS Package, and statistical analysis was performed using PLS and SPSS. According to the analysis results, it was confirmed that the higher the initial user's innovativeness, the higher the intention to use ChatGPT. In addition, the moderating effect analysis comparing the differences between the MZ generation and the non-MZ generation showed that policy expectations had a negative effect on the usefulness of ChatGPT use.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.4
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• pp.275-290
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• 2023

Background: Porcine pluripotent stem cells (pPSCs) would provide enormous potential for agriculture and biomedicine. However, authentic pPSCs have not established yet because standards for pPSCs-specific markers and culture conditions are not clear. Therefore, the present study reports comparative pluripotency characteristics in porcine induced pluripotent stem cells (piPSCs) derived from different viral transduction and reprogramming factors [Lenti-iPSCs (OSKM), Lenti-iPSCs (OSKMNL) and Sev-iPSCs (OSKM)]. Methods: Porcine fibroblasts were induced into Lenti-iPSCs (OSKM) and Lenti-iPSCs (OSKMNL) by using Lentiviral vector and Sev-iPSCs (OSKM) by using Sendaiviral vector. Expressions of endogenous or exogenous pluripotency-associated genes, surface marker and in vitro differentiation in between Lenti-piPSCs (OSKM), Lenti-iPSCs (OSKMNL) and Sev-piPSCs (OSKM) were compared. Results: Colonial morphology of Lenti-iPSCs (OSKMNL) closely resembles the naïve mouse embryonic stem cells colony for culture, whereas Sev-iPSCs (OSKM) colony is similar to the primed hESCs. Also, the activity of AP shows a distinct different in piPSCs (AP-positive (+) Lenti-iPSCs (OSKMNL) and Sev-iPSCs (OSKM), but AP-negative (-) Lenti-iPSCs (OSKM)). mRNAs expression of several marker genes (OCT-3/4, NANOG and SOX2) for pluripotency was increased in Lenti-iPSCs (OSKMNL) and Sev-iPSCs (OSKM), but Sev-iPSCs (OSKM). Interestingly, SSEA-1 of surface markers was expressed only in Sev-iPSCs (OSKM), whereas SSEA-4, Tra-1-60 and Tra-1-81 were positively expressed in Lenti-iPSCs (OSKMNL). Exogenous reprogramming factors continuously expressed in Lenti-iPSCs (OSKMNL) for passage 20, whereas Sev-iPSCs (OSKM) did not express any exogenous transcription factors. Finally, only Lenti-iPSCs (OSKMNL) express the three germ layers and primordial germ cells markers in aggregated EBs. Conclusions: These results indicate that the viral transduction system of reprograming factors into porcine differentiated cells display different pluripotency characteristics in piPSCs.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.6
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• pp.449-456
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• 2020

This study examines the relation between the quality of leader-member relationship and operational performance of processing enterprises employees in Vietnam, while job satisfaction and innovation are as a mediator variable. In depth interviews are first conducted with five managers and professional workers in five processing enterprises to determine the latent variables and build the structured questionnaire with observed variables. A quantitative survey with 438 employees and managers from 300 processing enterprises was carried out. The method of exploratory factor analysis (EFA), Cronbach's alpha analysis, and confirmatory factor analysis (CFA) was used to test the reliability, the convergent nature, and the consistency of the concepts. Structural equation modeling (SEM) is used to test the proposed model. The result shows that job satisfaction, innovation and operational performance have positive effects on the quality of leader-member relationship. The relationship between leaders and members had indirect impact on employee's operational performance via their job satisfaction and innovation, which illustrates a mediator role of job satisfaction and innovation for employees' performance. The findings of this study suggest that managers need to focus on developing relationship with employees to improve their satisfaction, innovation and performance.