65 research outputs found

    What Influences Influencers? Hiding Popularity Signals and Influencer Behavior

    Get PDF
    The burgeoning popularity of social media has shifted how social media users share and seek information through online platforms. Social media users are often motivated to show the “perfect side” of themselves on the platform, resulting in sharing manipulated appearances and positive aspects of their lives in order to garner more “likes” when comparing their popularity to others. Thus, social media users may often face inauthentic information, which may affect their behaviors on the platform. In this study, we utilize a change in Instagram policy—where they hide the number of likes from the platform— which started in September 2019 in East Asia. Specifically, we examine influencers’ post-generating behavior and post characteristics (e.g., whether it is focused on product vs influencers themselves and the degree of image manipulation). The results show that the number of endorsement postings increases, and influencers are more likely to generate influencer-focused postings after the intervention. In addition, we find that such effects are accentuated when influencers have a the larger follower base. Lastly, our findings suggest that the economic benefit (e.g., total weekly sales) that influencers gain increases after the intervention; however, such an effect is attenuated with influencers having a larger number of followers

    A New Reporter Vector System Based on Flow-Cytometry to Detect Promoter Activity

    Get PDF
    In this study, we report the development of a new dual reporter vector system for the analysis of promoter activity. This system employs green fluorescence emitting protein, EGFP, as a reporter, and uses red fluorescence emitting protein, DsRed, as a transfection control in a single vector. The expression of those two proteins can be readily detected via flow cytometry in a single analysis, with no need for any further manipulation after transfection. As this system allows for the simultaneous detection of both the control and reporter proteins in the same cells, only transfected cells which express the control protein, DsRed, can be subjected to promoter activity analysis, via the gating out of all un-transfected cells. This results in a dramatic increase in the promoter activity detection sensitivity. This novel reporter vector system should prove to be a simple and efficient method for the analysis of promoter activity

    Targeted mutagenesis in mouse cells and embryos using an enhanced prime editor

    Get PDF
    Prime editors, novel genome-editing tools consisting of a CRISPR-Cas9 nickase and an engineered reverse transcriptase, can induce targeted mutagenesis. Nevertheless, much effort is required to optimize and improve the efficiency of prime-editing. Herein, we introduce two strategies to improve the editing efficiency using proximal dead sgRNA and chromatin-modulating peptides. We used enhanced prime-editing to generate Igf2 mutant mice with editing frequencies of up to 47% and observed germline transmission, no off-target effects, and a dwarf phenotype. This improved prime-editing method can be efficiently applied to cell research and to generate mouse models.This study was supported by the Chung Yang, Cha Young Sun, & Jang Hi Joo Memorial Fund. This study was also supported by the Bio & Medical Technology Development Program of the National Research Foundation (NRF) of Korea (Korea Mouse Phenotyping Project, NRF-2013M3A9D5072550, NRF-2020M3A9D5A01082439, NRF2019R1A2C2087198, and NRF- 2019M3A9H1103792)

    Modulatory role of phospholipase D in the activation of signal transducer and activator of transcription (STAT)-3 by thyroid oncogenic kinase RET/PTC

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>RET/PTC (rearranged in transformation/papillary thyroid carcinomas) gene rearrangements are the most frequent genetic alterations identified in papillary thyroid carcinoma. Although it has been established that RET/PTC kinase plays a crucial role in intracellular signaling pathways that regulate cellular transformation, growth, and proliferation in thyroid epithelial cells, the upstream signaling that leads to the activation of RET/PTC is largely unknown. Based on the observation of high levels of PLD expression in human papillary thyroid cancer tissues, we investigated whether PLD plays a role in the regulating the RET/PTC-induced STAT3 activation.</p> <p>Methods</p> <p>Cancer tissue samples were obtained from papillary thyroid cancer patients (n = 6). The expression level of PLD was examined using immunohistochemistry and western blotting. Direct interaction between RET/PTC and PLD was analyzed by co-immunoprecipitation assay. PLD activity was assessed by measuring the formation of [<sup>3</sup>H]phosphatidylbutanol, the product of PLD-mediated transphosphatidylation, in the presence of <it>n</it>-butanol. The transcriptional activity of STAT3 was assessed by m67 luciferase reporter assay.</p> <p>Results</p> <p>In human papillary thyroid cancer, the expression levels of PLD2 protein were higher than those in the corresponding paired normal tissues. PLD and RET/PTC could be co-immunoprecipitated from cells where each protein was over-expressed. In addition, the activation of PLD by pervanadate triggered phosphorylation of tyrosine 705 residue on STAT-3, and its phosphorylation was dramatically higher in TPC-1 cells (from papillary carcinoma) that have an endogenous RET/PTC1 than in ARO cells (from anaplastic carcinoma) without alteration of total STAT-3 expression. Moreover, the RET/PTC-mediated transcriptional activation of STAT-3 was synergistically increased by over-expression of PLD, whereas the PLD activity as a lipid hydrolyzing enzyme was not affected by RET/PTC.</p> <p>Conclusion</p> <p>These findings led us to suggest that the PLD synergistically functions to activate the STAT3 signaling by interacting directly with the thyroid oncogenic kinase RET/PTC.</p

    Simulation of SVPWM Based Multivariable Control Method for a DFIG Wind Energy System

    Get PDF
    This paper deals with a variable speed device toproduce electrical energy on a power network based on adoubly-fed induction machine used in generating mode(DFIG) in wind energy system by using SVPWM powertransfer matrix. This paper presents a modeling and controlapproach which uses instantaneous real and reactive powerinstead of dq components of currents in a vector controlscheme. The main features of the proposed model comparedto conventional models in the dq frame of reference arerobustness and simplicity of realization. The sequential loopclosing technique is adopted to design a multivariable controlsystem including six compensators for a DFIG wind energysystem to capture the maximum wind power and to inject therequired reactive power to the generator. In this paperSVPWM method is used for better controlling of converters.It also provides fault ride through method to protect theconverter during a fault. The time-domain simulation of thestudy system is presented by using MATLAB Simulink to testthe system robustness, to validate the proposed model and toshow the enhanced tracking capability

    Parametric and non-parametric estimation of reference intervals for routine laboratory tests: an analysis of health check-up data for 260 889 young men in the South Korean military

    No full text
    Objectives Determination of reference intervals (RIs) using big data faces several obstacles due to heterogeneity in analysers, period and ethnicity. The present study aimed to establish the RIs for routine common blood count (CBC) and biochemistry laboratory tests in homogeneous, healthy, male Korean soldiers in their 20s using a large health check-up data set, comparing parametric and non-parametric estimation.Design A multicentre, cross-sectional study.Setting Seven armed forces hospitals in South Korea.Participants A total of 609 649 men underwent health examination when promoted to corporal between January 2015 and September 2021. 260 889 eligible individuals aged 20–25 were included in the analysis.Main outcomes and measures The RIs were established by parametric and non-parametric methods. In the parametric approach, maximum likelihood estimation was applied to measure the Box-Cox transformation parameter and the values at the 2.5th and 97.5th percentiles were recalculated. The non-parametric approach adopted the Tukey’s exclusion test and the values at the 2.5th and 97.5th percentiles were obtained. Classification by body mass index was also performed.Results The obtained RIs for haematology parameters were comparable between devices. If the values followed a Gaussian distribution, parametric and non-parametric methods were well matched for haematology and biochemical markers. When the values were right-skewed, the upper limits were higher with parametric than with non-parametric methods. Participants with obesity showed higher RIs for CBC, some liver function tests and some lipid profiles than participants without obesity.Conclusions Using data from healthy, male Korean soldiers in their 20s, we proposed the RIs for CBC and biochemical parameters, comparing parametric and non-parametric estimation. As such approaches based on large data sets become more prevalent, further studies are needed to discriminate eligible individuals and determine RIs in an extrapolated sample

    Construction and Enhancement of E. coli Biosensor for Detection of Landmine

    No full text
    As is well known, globally buried landmines cause serious problems such as human casualties and environmental pollution. An accurate and safe method of detecting landmines is needed, but no method has been developed to effectively detect various kinds of mines. Based on previous studies, a biosensor to detect DNT has been constructed by expressing gfp +, an enhanced fluorescence protein gene under the Pyqjfmut, a strong DNT-responsive promoter. However, the biosensor showed a weak signal at 3 ppb of low DNT concentration with high leaky expression. To solve these problems, genes related to DNT metabolism were identified through Tn-library screening and ASKA library screening to engineer them in order to improve the overall performance of the biosensor

    Obstructive Sleep Apnea and Nonalcoholic Fatty Liver Disease in the General Population: A Cross-Sectional Study Using Nationally Representative Data

    No full text
    (1) Background: To evaluate the association between obstructive sleep apnea (OSA) and nonalcoholic fatty liver disease (NAFLD) in the general population using a nationally representative sample from South Korea; (2) Methods: This study included 4275 adults aged &ge;40 years who completed the snoring, tiredness, observed apnea, high blood pressure, body mass index (BMI), age, neck circumference, and gender (STOP-Bang) questionnaire. The risk of OSA was stratified into low, intermediate, and high grades according to the STOP-Bang score. The prevalence of NAFLD according to the STOP-Bang score was calculated, and the increasing trend was measured. A complex sample multivariable regression analysis with adjustments for possible confounding variables was used to calculate the odds ratio of NAFLD and advanced fibrosis. Subgroup analysis was conducted with stratification based on sex and obesity status; (3) Results: We identified 1021 adults with NAFLD and 3254 adults without NAFLD. The prevalence of NAFLD increased significantly with higher STOP-Bang scores in both men and women. Participants of both sexes with high STOP-Bang scores were more likely to have NAFLD. Compared to non-obese individuals, the risk of NAFLD according to the STOP-Bang score was more intense in obese individuals. With respect to hepatic steatosis, there was no significant association between advanced fibrosis and STOP-Bang score; (4) Conclusions: OSA, the risk of which was measured using the STOP-Bang model, was closely associated with NAFLD in both Korean men and women. Clinicians should consider screening for NAFLD in individuals with a high STOP-Bang score
    • 

    corecore