422 research outputs found
How Rumors Spread and Stop over Social Media: a Multi-Layered Communication Model and Empirical Analysis
In this paper, we present a multi-layered communication (MLC) model that includes a trust-constructing procedure that can be used to explain how rumors spread and stop over social media. We define two structures in our MLC model: the social structure (SS) in the social layer, and the communication structure (CS) in the communicating layer. We propose two trust-building mechanisms (TBM): the social-based TBM (SBTBM) and the communicating-aimed TBM (CATBM). We discuss the trust-constructing procedure to demonstrate that an individual will sequentially decide to spread information based on three factors: the opinion environment, the individualâs social influence, and the cost to confirm the information. The model predicts that individuals will tend to create links with others in social layers to extend their social structures (social clustering principle) when they use social media. Thus, a rumor will spread because a spreading core is formed in the CS. However, a rumor will be stopped by interactions that occur in the SS. Our empirical case supports this prediction. We analyzed the topology of CS to indicate how a spreading core forms and CS evolves, and how a rumor stops spreading because social behaviors in SS encourage the development of more accurate information based on reality
Differential sensitivity of the cystic fibrosis (CF)-associated mutants G551D and G1349D to potentiators of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel.
The genetic disease cystic fibrosis (CF) is caused by loss of function of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel. Two CF mutants, G551D and G1349D, affect equivalent residues in the highly conserved LSGGQ motifs that are essential components of the ATP-binding sites of CFTR. Both mutants severely disrupt CFTR channel gating by decreasing mean burst duration (MBD) and prolonging greatly the interburst interval (IBI). To identify small molecules that rescue the gating defects of G551D- and G1349D-CFTR and understand better how these agents work, we used the patch clamp technique to study the effects on G551D- and G1349D-CFTR of phloxine B, pyrophosphate (PP(i)), and 2'-deoxy ATP (2'-dATP), three agents that strongly enhance CFTR channel gating. Phloxine B (5 microm) potentiated robustly G551D-CFTR Cl- channels by altering both MBD and IBI. In contrast, phloxine B (5 microm) decreased the IBI of G1349D-CFTR, but this effect was insufficient to rescue G1349D-CFTR channel gating. PP(i) (5 mm) potentiated weakly G551D-CFTR and was without effect on the G1349D-CFTR Cl- channel. However, by altering both MBD and IBI, albeit with different efficacies, 2'-dATP (1 mm) potentiated both G551D- and G1349D-CFTR Cl- channels. Using the ATP-driven nucleotide-binding domain dimerization model of CFTR channel gating, we suggest that phloxine B, PP(i) and 2'-dATP alter channel gating by distinct mechanisms. We conclude that G551D- and G1349D-CFTR have distinct pharmacological profiles and speculate that drug therapy for CF is likely to be mutation-specific
Effect of total stress path and gas volume change on undrained shear strength of gassy clay
Clay with free gas bubbles can be frequently encountered in the seabed. Gassy clay is an unsaturated soil, but its mechanical behavior cannot be described using conventional unsaturated soil mechanics because it has a composite internal structure with a saturated soil matrix and gas bubbles. The gas bubbles can have either a detrimental or beneficial effect on the undrained shear strength of clay. New lower and upper bounds for the undrained shear strength of gassy clay are derived by considering the effect of total stress path and plastic hardening of the saturated soil matrix. For the upper bound, it is assumed that there is only bubble flooding, and the shear strength of an unsaturated soil sample is the same as that of the saturated soil matrix. Bubble flooding makes the saturated soil matrix partially drained and increases the undrained shear strength. The amount of bubble flooding is calculated using the modified Cam-Clay model and Boyle's law for ideal gas. The lower bound is derived based on the assumption that the entire soil fails without bubble flooding and the gas cavity size evolves due to plastic hardening of the saturated soil matrix. Compared with Wheeler's upper and lower bounds that do not consider plastic hardening of the saturated soil matrix, the new theoretical results give a better prediction of the undrained shear strength of gassy clays, especially for the upper bound. Implications for constitutive modeling of gassy clay are discussed based on the new research outcomes
Cognitive flexibility as a protective factor for empathy
Although cognitive flexibility has always been considered essential to empathy, the relevant findings have been inconsistent. Inconsistent results may be because cognitive flexibility is a multi-level structure, while empathy is also a multilayer structure, and there are differences in how researchers define and measure cognitive flexibility. Therefore, the study explores the relationship between cognitive flexibility and empathy from a multi-dimensional perspective. This study involved 105 China students aged between 18 and 22 (M ageâ=â20.26, SDâ=â2.00) who completed the Cognitive Flexibility Scale (cognitive flexibility trait, cognitive flexibility at the individual level), perspective-switching flexibility task (perspective-switching flexibility, cognitive flexibility at the cognitive level), the Interpersonal Reactivity Index scale (IRI, traits empathy), Multi-dimensional Empathy Test (state empathy), 2-back task (inhibitory control), and Stroop task (working memory). After controlling for additional variables, the results showed that: (1) Cognitive flexibility traits negatively predicted trait cognitive (IRI-PT) and affective empathy (IRI-EC). (2) The Other/Self perspective-switching flexibility negatively predicted the affective component of state empathy. (3) Cognitive flexibility traits and Other/Self perspective-switching flexibility negatively predicted empathy even after controlling for one of these. The studyâs results suggested that cognitive flexibility negatively predicts empathy and is a protective factor for reducing the cost of empathy and promoting emotion regulation
Codeposition of Platinum and Gold on Nickel Wire Electrodes via Galvanic Replacement Reactions for Electrocatalytic Oxidation of Alcohols
Codeposition of Pt and Au on Ni wire was performed using a simple treatment of immersing Ni wire in aqueous solutions containing both KâPtClâ and HAuClâ. For evaluating the electrochemical properties of the thus-prepared electrodes, cyclic voltammograms (CVs) of 1.0 M ethanol in 1.0 M NaOH aqueous solutions were recorded. Compared with Pt- or Au-deposited Ni wire electrodes prepared by treating Ni wire in aqueous solutions of a single component, e.g., 1.0 mM KâPtClâ or 1.0 mM HAuClâ, a noteworthy increase in the electrocatalytic current was observed for the oxidation of ethanol with a PtAu-codeposited Ni (PtAu/Ni) wire electrode even when it was prepared in an aqueous solution containing both 0.10 mM KâPtClâ and 0.10 mM HAuClâ. In addition, the shape and the peak potentials of CVs recorded using PtAu/Ni wire electrodes were found to be different from those recorded with the Pt- or Au-deposited Ni wire electrodes. Because the CV responses typical of the PtAu/Ni wire electrodes were observed even when a PtAu/Ni wire electrode was prepared in an aqueous solution containing both 0.010 mM KâPtClâ and 1.0 mM HAuClâ, it is considered that a small amount of Pt was effectively modified or incorporated and affected the electrochemical properties significantly. The CV results for ethanol oxidation were compared with those for the electrocatalytic oxidations of methanol, 1-propanol, and 2-propanol. Besides, the CV results recorded with the present PtAu/Ni wire electrodes are discussed in comparison with some previous results obtained using other PtAu nanoelectrocatalysts
Modification with platinum of silver-deposited nickel wire electrodes for electrocatalytic oxidation of alcohols
A silver-deposited nickel (Ag/Ni) wire electrode was prepared via a galvanic replacement reaction between Agâș and Ni wire in aqueous solution. It was then found that the Ag/Ni wire electrode could be modified with Pt simply by treating it in an aqueous solution of KâPtClâ. Although the deposition of Ag on Ni wire was limited in amount, forming Ag deposits less than 100 nm in size, a considerable increase in the electrocatalytic currents for the oxidation of alcohols could be observed after further modification of the Ag/Ni wire electrodes with Pt. This is in contrast to the fact that it was difficult to produce sufficient electrocatalytic response by modifying Ni wire with Pt directly via a simple galvanic replacement between PtClâÂČâ» and Ni wire. Thus, the prior deposition of Ag was found to strongly promote modification with Pt via a simple stepwise treatment using AgNOâ and KâPtClâ. This approach should be effective in modifying various Ni materials with Pt, including Ni microparticles
Relationship between the cumulative exposure to atherogenic index of plasma and ischemic stroke: A retrospective cohort study
Background: Atherogenic index of plasma (AIP) has been demonstrated as a surrogate marker for ischemic stroke, but there is limited evidence for the effect of long-term elevation of AIP on ischemic stroke. Therefore, we aimed to characterize the relationship between cumulative exposure to AIP and the risk of ischemic stroke. Methods: A total of 54,123 participants in the Kailuan Study who attended consecutive health examinations in 2006, 2008, and 2010 and had no history of ischemic stroke or cancer were included. The time-weighted cumulative AIP (cumAIP) was calculated as a weighted sum of the mean AIP values for each time interval and then normalized to the total duration of exposure (2006â2010). Participants were divided into four groups according to quartile of cumAIP: the Q1 group, †â0.50; Q2 group, â 0.50 to â 0.12; Q3 group, â 0.12 to 0.28; and Q4 group, â„ 0.28. Cox proportional hazard models were used to evaluate the relationship between cumAIP and ischemic stroke by calculating hazard ratios (HRs) and 95% confidence intervals (95% CIs). Results: After a median follow-up of 11.03 years, a total of 2,742 new ischemic stroke events occurred. The risk of ischemic stroke increased with increasing quartile of cumAIP. After adjustment for potential confounders, Cox regression models showed that participants in the Q2, Q3, and Q4 groups had significantly higher risks of ischemic stroke than those in the Q1 group. The HRs (95% CIs) for ischemic stroke in the Q2, Q3, and Q4 groups were 1.17 (1.03, 1.32), 1.33 (1.18, 1.50), and 1.45 (1.28, 1.64), respectively. The longer duration of high AIP exposure was significantly associated with increased ischemic stroke risk. Conclusions: High cumulative AIP is associated with a higher risk of ischemic stroke, which implies that the long-term monitoring and maintenance of an appropriate AIP may help prevent such events
Increased expression of Gremlin1 promotes proliferation and epithelial mesenchymal transition in gastric cancer cells and correlates with poor prognosis of patients with gastric cancer
Background/Aim: Gremlin1 (GREM1) plays an important role in certain malignancies by antagonising bone morphogenetic proteins and regulating angiogenesis directly/indirectly. The present study aimed to investigate the role of Gremlin1 in the development and progression of gastric cancer (GC). Materials and Methods: Expression of GREM1 in GCs was examined using quantitative real time PCR and The Cancer Genomic Atlas (TCGA) data. Influence on cellular functions was determined in both Gremlin1 knockdown and overexpression cell line models. Results: GREM1 expression was up-regulated in GCs, which was correlated with poorer survival. Increased GREM1 expression was significantly correlated with tumour growth/invasion and lymphatic metastasis. Gremlin1 promoted proliferation and tumourigenic capacity of GC cells in vitro. GREM1 expression was associated with epithelial mesenchymal transition (EMT), angiogenesis and lymphangiogenesis in GC. Conclusion: Increased GREM1 expression in GCs is associated with disease progression and poor prognosis in which EMT, angiogenesis and lymphangiogenesis are likely involved
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