337 research outputs found
Forming relationship commitments to online communities: The role of social motivations
[[abstract]]Although administrators of online communities (OCs) may focus on improving their OCs through upgrading technology and enhancing the usability of their OCs to attract additional users, the level of OC participation may be associated with social motives. The purpose of this study is to understand how social motivations (that is, network externalities and social norms) affect members committed to OCs. This study tests the hypotheses on data collected from 396 undergraduate students. Data analyses show that network externalities and social norms directly influence social interaction ties, which subsequently results in commitment toward a community. Social norms also directly influence relationship commitments to a community. The results provide insights into how social motivations lead to commitment to an OC, reminding OC administrators to encourage member commitment to the OC from the perspective of social motivations.[[notice]]補正完畢[[incitationindex]]SSCI[[booktype]]紙本[[booktype]]電子
Investigating member commitment to virtual communities using an integrated perspective
[[abstract]]Purpose – Although the number of virtual communities has increased dramatically over the past few years, attracting and maintaining members remains the biggest challenge to establishing virtual social networks. This study seeks to integrate the roles of individual factors (issue involvement), social factors (social interaction), and system factors (system interactivity), and to explore how these factors contribute to member commitment in virtual communities.
Design/methodology/approach – A total of 402 undergraduate students, who are all current members of virtual communities, participated in this study. Data were analyzed using structural equation modeling (SEM).
Findings – The findings reveal that member commitment to communities was influenced more by their issue involvement compared to their perceived social interaction or perceived system interactivity.
Originality/value – This research contributes to online community literature by integrating critical antecedent factors in the field of community commitment behavior. The findings indicate that issue involvement is more important than social interaction and system interactivity for influencing member commitment to communities. Additionally, the findings suggest that online community administrators should consider community positioning and topic selecting programs when attempting to influence users to commit to communities.[[notice]]補正完畢[[incitationindex]]SSCI[[booktype]]紙
Perceived Causes of Autism Spectrum Disorders among Taiwanese Parents of Affected Children: A Qualitative Study
Background: Autism Spectrum Disorders (ASDs) represent a complex group of neurodevelopment and mental disorders. Currently, the etiologies for ASDs are unclear. Consequently, it is important to assess the perceptions of ASDs among parents of affected children, as their perceptions can impact parent-child bonding, disease prognosis and treatment, subsequent education and living environment of the affected child, and interactions with health professionals.  The majority of available research regarding parental perceptions of ASDs has been conducted in the Western countries. Given that culture plays an important role in parents’ views regarding the causes of ASDs, this study aims to examine perceptions of the etiology of ASDs among parents in Taiwan – an Asian country strongly influenced by the Chinese culture.Methods: Participants were recruitment through ASDs organizations in Taiwan. In-depth interviews were performed with 31 mothers and 8 fathers who had at least one child diagnosed with ASDs. All interviews were audio-recorded, transcribed, and subsequently analyzed via content analysis.Results: The themes of ASDs etiologies identified by participants from the highest to the lowest frequencies were: genetics (n=30; 76.9%), problems during mother’s pregnancy (n=18; 46.2%), complications/situations during delivery (n=13; 33.3%), vaccination (n=11; 28.2%), environmental pollutions (n=10; 25.6%), children’s non-ASDs related health problems and unintended injuries (n=9; 23.1%), parenting style (n=7; 17.9%), parents’ occupation (n=7; 17.9%), spiritual or religious factors (n=6; 15.4%), children’s diet (n=2; 5.1%), maternal age at the time of pregnancy (n=1; 2.6%), and children’s use of traditional Chinese medicine (n=1; 2.6%).Discussion: Taiwanese parents held diverse views on the causes of ASDs. Overall, parental beliefs were based on culture, scientific evidence/research and uninformed non-scientific views. Our results may help health professionals and researchers identify gaps in parents’ knowledge of ASDs and understand commonly held misperceptions about the causes of ASDs. Further, findings generated from this qualitative research may serve as the foundation for a research instrument to survey beliefs regarding the causes of ASDs among larger samples of Taiwanese parents who have children affected by ASDs
RNA topoisomerase is prevalent in all domains of life and associates with polyribosomes in animals
DNA Topoisomerases are essential to resolve topological problems during DNA metabolism in all species. However, the prevalence and function of RNA topoisomerases remain uncertain. Here, we show that RNA topoisomerase activity is prevalent in Type IA topoisomerases from bacteria, archaea, and eukarya. Moreover, this activity always requires the conserved Type IA core domains and the same catalytic residue used in DNA topoisomerase reaction; however, it does not absolutely require the non-conserved carboxyl-terminal domain (CTD), which is necessary for relaxation reactions of supercoiled DNA. The RNA topoisomerase activity of human Top3β differs from that of Escherichia coli topoisomerase I in that the former but not the latter requires the CTD, indicating that topoisomerases have developed distinct mechanisms during evolution to catalyze RNA topoisomerase reactions. Notably, Top3β proteins from several animals associate with polyribosomes, which are units of mRNA translation, whereas the Top3 homologs from E. coli and yeast lack the association. The Top3β-polyribosome association requires TDRD3, which directly interacts with Top3β and is present in animals but not bacteria or yeast. We propose that RNA topoisomerases arose in the early RNA world, and that they are retained through all domains of DNA-based life, where they mediate mRNA translation as part of polyribosomes in animals
Phosphorylation of LCRMP-1 by GSK3β Promotes Filopoda Formation, Migration and Invasion Abilities in Lung Cancer Cells
LCRMP-1, a novel isoform of CRMP-1, can promote cancer cell migration, invasion and associate with poor clinical outcome in patients with non-small-cell lung cancer (NSCLC). However, the underlying regulatory mechanisms of LCRMP-1 in cancer cell invasiveness still remain obscure. Here, we report that GSK3β can phosphorylate LCRMP-1 at Thr-628 in consensus sequences and this phosphorylation is crucial for function of LCRMP-1 to promote filopodia formation, migration and invasion in cancer cells. Impediment of Thr-628 phosphorylation attenuates the stimulatory effects of LCRMP-1 on filopodia forming, migration and invasion abilities in cancer cells; simultaneously, kinase-dead GSK3β diminishes regulation of LCRMP-1 on cancer cell invasion. Furthermore, we also found that patients with low-level Ser-9-phosphorylated GSK3β expression and high-level LCRMP-1 expression have worse overall survival than those with high-level inactive GSK3β expressions and low-level LCRMP-1 expressions (P<0.0001). Collectively, these results demonstrate that GSK3β-dependent phosphorylation of LCRMP-1 provides an important mechanism for regulation of LCRMP-1 on cancer cell invasiveness and clinical outcome
Upregulation of Pd-L1 by Sars-Cov-2 Promotes Immune Evasion
Patients with severe COVID-19 often suffer from lymphopenia, which is linked to T-cell sequestration, cytokine storm, and mortality. However, it remains largely unknown how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces lymphopenia. Here, we studied the transcriptomic profile and epigenomic alterations involved in cytokine production by SARS-CoV-2-infected cells. We adopted a reverse time-order gene coexpression network approach to analyze time-series RNA-sequencing data, revealing epigenetic modifications at the late stage of viral egress. Furthermore, we identified SARS-CoV-2-activated nuclear factor-κB (NF-κB) and interferon regulatory factor 1 (IRF1) pathways contributing to viral infection and COVID-19 severity through epigenetic analysis of H3K4me3 chromatin immunoprecipitation sequencing. Cross-referencing our transcriptomic and epigenomic data sets revealed that coupling NF-κB and IRF1 pathways mediate programmed death ligand-1 (PD-L1) immunosuppressive programs. Interestingly, we observed higher PD-L1 expression in Omicron-infected cells than SARS-CoV-2 infected cells. Blocking PD-L1 at an early stage of virally-infected AAV-hACE2 mice significantly recovered lymphocyte counts and lowered inflammatory cytokine levels. Our findings indicate that targeting the SARS-CoV-2-mediated NF-κB and IRF1-PD-L1 axis may represent an alternative strategy to reduce COVID-19 severity
Anti-Arthritic Effects of Magnolol in Human Interleukin 1β-Stimulated Fibroblast-Like Synoviocytes and in a Rat Arthritis Model
Fibroblast-like synoviocytes (FLS) play an important role in the pathologic processes of destructive arthritis by producing a number of catabolic cytokines and metalloproteinases (MMPs). The expression of these mediators is controlled at the transcriptional level. The purposes of this study were to evaluate the anti-arthritic effects of magnolol (5,5′-Diallyl-biphenyl-2,2′-diol), the major bioactive component of the bark of Magnolia officinalis, by examining its inhibitory effects on inflammatory mediator secretion and the NF-κB and AP-1 activation pathways and to investigate its therapeutic effects on the development of arthritis in a rat model. The in vitro anti-arthritic activity of magnolol was tested on interleukin (IL)-1β-stimulated FLS by measuring levels of IL-6, cyclooxygenase-2, prostaglandin E2, and matrix metalloproteinases (MMPs) by ELISA and RT-PCR. Further studies on how magnolol inhibits IL-1β-stimulated cytokine expression were performed using Western blots, reporter gene assay, electrophoretic mobility shift assay, and confocal microscope analysis. The in vivo anti-arthritic effects of magnolol were evaluated in a Mycobacterium butyricum-induced arthritis model in rats. Magnolol markedly inhibited IL-1β (10 ng/mL)-induced cytokine expression in a concentration-dependent manner (2.5–25 µg/mL). In clarifying the mechanisms involved, magnolol was found to inhibit the IL-1β-induced activation of the IKK/IκB/NF-κB and MAPKs pathways by suppressing the nuclear translocation and DNA binding activity of both transcription factors. In the animal model, magnolol (100 mg/kg) significantly inhibited paw swelling and reduced serum cytokine levels. Our results demonstrate that magnolol inhibits the development of arthritis, suggesting that it might provide a new therapeutic approach to inflammatory arthritis diseases
Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas
This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing
molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
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