91 research outputs found

    Understanding the Association between Star Ratings and Review Helpfulness: The Perspectives of Expectation Confirmation Theory and Negativity Bias

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    Consisting of textual, multimedia, and numerical information elements, online consumer reviews (OCR) have been considered an essential information source of products for prospective consumers. Researchers have made significant efforts to comprehend how these information elements are associated with OCRs’ information value or helpfulness. However, there is a paucity of theoretical evidence on consumers’ perception and evaluation of star ratings and their information, even though star ratings as numerical information cues can imply multiple meanings. In this study, we leverage (1) expectation-confirmation theory to delineate star ratings as the extent of consumer satisfaction and (2) negativity bias to explain the relationship between star ratings and helpfulness. Using 45,621 reviews of 20 products across three categories, we empirically find that our theoretical approaches improve our understanding of the effect of star ratings on helpfulness. Therefore, this study contributes to the extant literature on OCRs by providing the theory-based evaluation of star ratings in relation to helpfulness

    Are Neutral Sentiments Worth Considering When Investigating Online Consumer Reviews? Their Relationship with Review Ratings

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    Online consumer reviews (OCRs) play an important role for firms to understand consumer satisfaction. Prior research on OCRs has used sentiment analysis to identify and quantify consumers’ subjective impressions in terms of positive and negative sentiments. However, OCRs also contain objective facts about the product or service, which are represented by neutral sentiments. In this study, we argue that it is important to distinguish neutral sentiments from those of positivity and negativity when investigating consumer satisfaction. Through a lens of expectation-confirmation theory, we delineate the roles of subjective information in relation to consumer satisfaction, in the sense that consumer satisfaction is mainly formed by one’s subjective expectations and evaluations, not by objective facts of the product or service. The empirical results obtained from OCRs about hotels demonstrate that consumer satisfaction is significantly higher in positive OCRs than neutral ones, and significant lower in negative OCRs than neutral ones. Furthermore, neutral sentiments drastically improve the explanatory power of empirical models, thereby enhancing our understanding of consumer satisfaction. Academically, this study sheds light on the importance of neutral sentiments. Practically, neutral sentiments, when being separated from the other two sentiment categories, contribute to more accurately reflecting consumer satisfaction

    POMY: 햅틱 피드백을 적용한 몰입형 영어 학습 시스템

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    국내110Yscopu

    When More is More and Less is More: Depth and Breadth of Product Reviews and Their Effects on Review Helpfulness

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    With the growth of online shopping coupled with mobile technology, user-generated product reviews have become an important source of information for product diagnosticity. A significant academic endeavor has been made to comprehend what information factors of reviews help prospective customers better diagnose products. One such factor is review depth that is estimated by the number of a review’s words. We propose review breadth as an additional factor based on a review’s number of topics—the more review breadth, the more diverse information. By conducting the statistical and predictive analyses, we demonstrate that review breadth reliably measures a review’s information. This study makes academic and practical contributions. For academic researchers, review breadth is worth considering as a factor to estimate a review’s information over and above review depth. Based on the two information factors of review breadth and review depth, practitioners can recommend more helpful product reviews to their prospective customers

    Pitfalls and Important Issues in Testing Reliability Using Intraclass Correlation Coefficients in Orthopaedic Research

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    Background: Intra-class correlation coeffi cients (ICCs) provide a statistical means of testing the reliability. However, their interpretationis not well documented in the orthopedic fi eld. The purpose of this study was to investigate the use of ICCs in the orthopedicliterature and to demonstrate pitfalls regarding their use. Methods: First, orthopedic articles that used ICCs were retrieved from the Pubmed database, and journal demography, ICC modelsand concurrent statistics used were evaluated. Second, reliability test was performed on three common physical examinationsin cerebral palsy, namely, the Thomas test, the Staheli test, and popliteal angle measurement. Thirty patients were assessed bythree orthopedic surgeons to explore the statistical methods testing reliability. Third, the factors affecting the ICC values were examinedby simulating the data sets based on the physical examination data where the ranges, slopes, and interobserver variabilitywere modifi ed. Results: Of the 92 orthopedic articles identifi ed, 58 articles (63%) did not clarify the ICC model used, and only 5 articles (5%)described all models, types, and measures. In reliability testing, although the popliteal angle showed a larger mean absolute differencethan the Thomas test and the Staheli test, the ICC of popliteal angle was higher, which was believed to be contrary to thecontext of measurement. In addition, the ICC values were affected by the model, type, and measures used. In simulated data sets,the ICC showed higher values when the range of data sets were larger, the slopes of the data sets were parallel, and the interobservervariability was smaller. Conclusions: Care should be taken when interpreting the absolute ICC values, i.e., a higher ICC does not necessarily mean lessvariability because the ICC values can also be affected by various factors. The authors recommend that researchers clarify ICCmodels used and ICC values are interpreted in the context of measurement.N

    A functional regulatory variant of MYH3 influences muscle fiber-type composition and intramuscular fat content in pigs

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    Muscle development and lipid accumulation in muscle critically affect meat quality of livestock. However, the genetic factors underlying myofiber-type specification and intramuscular fat (IMF) accumulation remain to be elucidated. Using two independent intercrosses between Western commercial breeds and Korean native pigs (KNPs) and a joint linkage-linkage disequilibrium analysis, we identified a 488.1-kb region on porcine chromosome 12 that affects both reddish meat color (a*) and IMF. In this critical region, only the MYH3 gene, encoding myosin heavy chain 3, was found to be preferentially overexpressed in the skeletal muscle of KNPs. Subsequently, MYH3-transgenic mice demonstrated that this gene controls both myofiber-type specification and adipogenesis in skeletal muscle. We discovered a structural variant in the promotor/regulatory region of MYH3 for which Q allele carriers exhibited significantly higher values of a* and IMF than q allele carriers. Furthermore, chromatin immunoprecipitation and cotransfection assays showed that the structural variant in the 5-flanking region of MYH3 abrogated the binding of the myogenic regulatory factors (MYF5, MYOD, MYOG, and MRF4). The allele distribution of MYH3 among pig populations worldwide indicated that the MYH3 Q allele is of Asian origin and likely predates domestication. In conclusion, we identified a functional regulatory sequence variant in porcine MYH3 that provides novel insights into the genetic basis of the regulation of myofiber type ratios and associated changes in IMF in pigs. The MYH3 variant can play an important role in improving pork quality in current breeding programs

    Ascorbic acid extends replicative life span of human embryonic fibroblast by reducing DNA and mitochondrial damages

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    Ascorbic acid has been reported to extend replicative life span of human embryonic fibroblast (HEF). Since the detailed molecular mechanism of this phenomenon has not been investigated, we attempted to elucidate. Continuous treatment of HEF cells with ascorbic acid (at 200 µM) from 40 population doubling (PD) increased maximum PD numbers by 18% and lowered SA-β-gal positive staining, an aging marker, by 2.3 folds, indicating that ascorbic acid extends replicative life span of HEF cells. Ascorbic acid treatment lowered DCFH by about 7 folds and Rho123 by about 70%, suggesting that ascorbic acid dramatically decreased ROS formation. Ascorbic acid also increased aconitase activity, a marker of mitochondrial aging, by 41%, indicating that ascorbic acid treatment restores age-related decline of mitochondrial function. Cell cycle analysis by flow cytometry revealed that ascorbic acid treatment decreased G1 population up to 12%. Further western blot analysis showed that ascorbic acid treatment decreased levels of p53, phospho-p53 at ser 15, and p21, indicating that ascorbic acid relieved senescence-related G1 arrest. Analysis of AP (apurinic/apyrimidinic) sites showed that ascorbic acid treatment decreased AP site formation by 35%. We also tested the effect of hydrogen peroxide treatment, as an additional oxidative stress. Continuous treatment of 20 µM of hydrogen peroxide from PD 40 of HEF cells resulted in premature senescence due to increased ROS level, and increased AP sites. Taken together, the results suggest that ascorbic acid extends replicative life span of HEF cells by reducing mitochondrial and DNA damages through lowering cellular ROS

    The Function of Heterodimeric AP-1 Comprised of c-Jun and c-Fos in Activin Mediated Spemann Organizer Gene Expression

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    BACKGROUND:Activator protein-1 (AP-1) is a mediator of BMP or FGF signaling during Xenopus embryogenesis. However, specific role of AP-1 in activin signaling has not been elucidated during vertebrate development. METHODOLOGY/PRINCIPAL FINDINGS:We provide new evidence showing that overexpression of heterodimeric AP-1 comprised of c-jun and c-fos (AP-1(c-Jun/c-Fos)) induces the expression of BMP-antagonizing organizer genes (noggin, chordin and goosecoid) that were normally expressed by high dose of activin. AP-1(c-Jun/c-Fos) enhanced the promoter activities of organizer genes but reduced that of PV.1, a BMP4-response gene. A loss of function study clearly demonstrated that AP-1(c-Jun/c-Fos) is required for the activin-induced organizer and neural gene expression. Moreover, physical interaction of AP-1(c-Jun/c-Fos) and Smad3 cooperatively enhanced the transcriptional activity of goosecoid via direct binding on this promoter. Interestingly, Smad3 mutants at c-Jun binding site failed in regulation of organizer genes, indicating that these physical interactions are specifically necessary for the expression of organizer genes. CONCLUSIONS/SIGNIFICANCE:AP-1(c-Jun/c-Fos) plays a specific role in organizer gene expression in downstream of activin signal during early Xenopus embryogenesis
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