869 research outputs found

    Persistent nonequilibrium effects in generalized Langevin dynamics of nonrelativistic and relativistic particles

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    Persistent nonequilibrium effects such as the memory of the initial state, the ballistic diffusion, and the break of the equipartition theorem and the ergodicity in Brownian motions are investigated by analytically solving the generalized Langevin equation of nonrelativistic Brownian particles with colored noise. These effects can also be observed in the Brownian motion of relativistic particles by numerically solving the generalized Langevin equation for specially chosen memory kernels. Our analyses give rise to think about the possible anomalous motion of heavy quarks in relativistic heavy-ion collisions.Comment: 13 pages, 12 figures, title changed, two figues added, one figure updated, text updated, references added, results unchanged, published versio

    A Meta-Analysis on the Determinants of Online Review Helpfulness

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    Online consumer reviews can help customers decrease uncertainty and risk faced in online shopping. However, information overload and conflicting comments in online reviews can get consumers confused. Therefore, it is important for both researchers and practitioners to understand the characteristics of helpful reviews. But studies examining the determinants of perceived review helpfulness produce mixed findings. We review extant research about the determinant factors of perceived helpfulness. Conflicting findings exist for six review related factors, namely review extremity, review readability, review total votes, linear review rating, quadratic review rating, and review sentiment. We conduct a meta-analysis to reconcile the contradictory findings on the influence of review related factors over perceived review helpfulness. The meta-analysis results confirm that review extremity, readability, total votes, and positive sentiment have a negative influence on helpfulness, but review rating is positively related to helpfulness. We also examine those studies whose findings are contradictive with the meta-analysis results. Measure discrepancy and reviewed product type are the two main reasons why mixed findings exist in extant research

    Orbital Stability of Solitary Waves for Generalized Symmetric Regularized-Long-Wave Equations with Two Nonlinear Terms

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    This paper investigates the orbital stability of solitary waves for the generalized symmetric regularized-long-wave equations with two nonlinear terms and analyzes the influence of the interaction between two nonlinear terms on the orbital stability. Since J is not onto, Grillakis-Shatah-Strauss theory cannot be applied on the system directly. We overcome this difficulty and obtain the general conclusion on orbital stability of solitary waves in this paper. Then, according to two exact solitary waves of the equations, we deduce the explicit expression of discrimination d′′(c) and give several sufficient conditions which can be used to judge the orbital stability and instability for the two solitary waves. Furthermore, we analyze the influence of the interaction between two nonlinear terms of the equations on the wave speed interval which makes the solitary waves stable

    Relationship between adherence to anti-diabetic medication and depression among patients with diabetes mellitus in three selected Chinese hospitals

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    Purpose: To determine the relationship between adherence to anti-diabetic medication and depression among patients with diabetes mellitus in three hospitals in Chinese.Methods: This research utilized a quantitative and descriptive design, and included 200 diabetic patients who fulfilled the inclusion criteria for recruitment through a convenient sampling technique. The study applied Beck’s depression inventory II scale for assessment of depression, and a questionnaire for adherence to anti-diabetic medication.Results: A total of 64 (32 %) participants had diabetes for 6 to 10 years. There was a high level of adherence to anti-diabetic medication in 96 patients (48 %); 74 participants (37 %) had moderate adherence to anti-diabetic medication, while 30 patients (15 %) had low adherence. A majority of the patients (181, 90.5 %) had no depression. Six (6) patients (3 %) had mild mood disturbance, 2 patients (1 %) had borderline clinical depression, while 11patients (5.5 %) experienced moderate depression.Adherence to anti-diabetic medication was not associated with depression (p = 0.068). However, depression was associated with age ˃ 50 years (p = 0.041), female sex (p = 0.043), long duration of illness (> 5-years) (p = 0.048), and presence of one or more comorbidities (p = 0.049).Conclusion: There was no association between adherence to anti-diabetic medication and depression among diabetic patients. Keywords: Adherence to anti-diabetic medication, Beck’s depression inventory II, Depression, Diabetes mellitu

    China’s Scientific Journals in a Transforming Period: Present Situation and Developing Strategies

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    Based on a detailed analysis of the global academic impact of China’s scientific journals, as well as of the publishing strategies and communication media used by their publishers, we conclude that the Science, Technology, and Medicine (STM) journal publishing industry in China is going through very rapid transformation. Journals are attempting to become more broadly international, and doing so by adopting new digital production methods and commercial models. In light of these efforts, we discuss the current challenges to the development of China’s scientific journal industry and suggest strategies that may be useful for reaching key goals

    Adherence to anti-tuberculosis treatment among pulmonary tuberculosis patients: a qualitative and quantitative study

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    BACKGROUND: Tuberculosis (TB) patients have difficulty following a long-term treatment regimen. Efforts to improve treatment outcomes require better understanding of adherence as a complex behavioral issue and of the particular barriers to and facilitators of patient adherence. METHODS: This study was carried out in Jiangsu Province of China with both quantitative and qualitative approaches. For the quantitative study, 780 sputum-smear positive TB patients consecutively registered since 2006 in 13 counties (districts) were queried with a structured questionnaire. Patients who had missed 10% of their total prescribed doses of TB drugs were deemed as non-adherent. Risks for non-adherence were estimated by computing odds ratios (ORs) and their 95% confidence intervals (95% CIs) using a logistic regression model. We also invited 20 TB patients and 10 local health workers for in-depth interviews. We then used content analysis based on this qualitative study to explore factors associated with non-adherence. RESULTS: The proportion of non-adherence among 670 patients was 12.2%. Univariate analysis showed that patients, who were illiterate, divorced/widowed, lacked health insurance and were migrants, were more likely to be non-adherent. The crude ORs(95%CIs) were 2.38(1.37-4.13), 2.42(1.30-4.52), 1.89(1.07-3.32) and 1.98(1.03-3.83), respectively. The risk of non-adherence was lower among patients whose treatment was given under direct observation by village doctors or regular home visits by health workers, with ORs (95% CIs) of 0.19(0.10-0.36) and 0.23(0.10-0.51), respectively. In multivariate analysis, factors associated with non-adherence included illiteracy (OR: 2.42; 95% CI: 1.25-4.67) and direct observation by village doctors (OR: 0.23; 95% CI: 0.11-0.45). The in-depth interviews indicated that financial burdens and extra medical expenditures, adverse drug reactions, and social stigma were additional potential factors accounted for non-adherence. CONCLUSION: More importance should be given to treatment adherence under the current TB control program. Heavy financial burdens, lack of social support, adverse drug reactions and personal factors are associated with non-adherence. Direct observation and regular home visits by health workers appear to reduce the risk of non-adherence. More patient-centered interventions and greater attention to structural barriers are needed to improve treatment adherence

    Networked Non-fragile H∞ Control for Lipschitz Nonlinear System with Quantization and Packet Dropout in Both Feedback and Forward Channels

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    The networked non-fragile H∞ control problem for Lipschitz nonlinear system with quantization and packet dropout in both feedback and forward channels is investigated in this paper. The sensor measurement and controller output are quantized by logarithmic quantizers before transmitted over the network. The packet transmissions in the communication channels from the sensor to the controller and from the controller to the actuator are modeled as Markov chains respectively. Based on the Lyapunov functional approach, the networked non-fragile H∞ controller is designed to stabilize the Lipschitz nonlinear system and achieve the prescribed H∞ performance. Finally a numerical example is provided to illustrate the effectiveness of the proposed method
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