17,406 research outputs found

    On the variable capacity property of CC/DS-CDMA systems

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    A complete complementary code based direct sequence code division multiple access (CC/DS-CDMA) system has been proposed recently as a potential candidate for beyond third generation (B3G) wireless communications. This paper addresses the issues that design of efficient code assignment schemes should be based on a flexible physical layer support, which is extremely important for emerging cross-layer designs in future wireless applications. The study in this paper considers a CC/DS-CDMA system with multiple time slots, three traffic classes and two dynamic code-flock assignment schemes, namely random assignment (RA) and compact assignment (CA). Simulation results show that the CC/DS-CDMA system has variable capacity property (VCP), which is sensitively affected by different code-flock assignment schemes. In general, CA can offer lower blocking probability, whereas RA can offer a larger mean system capacity and higher throughput when offered traffic is heavy

    A robotic system for rapid prototyping

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    Reducing prototyping time is a good way to make the product development cycle shorter. This can be achieved in two ways: one is to develop new prototyping technologies like stereolithography apparatus (SLA), selective laser sintering (SLS) etc.; the other is to improve the principal existing technique which is CNC based method. In this paper, a robotic system for rapid prototyping which is an enhancement of the CNC based method is presented. A robot arm holding a milling tool is used to machine the prototype of a solid model drawn in commercial CAD systems. The rough cut and finish cut NC tool path for the robot arm are generated automatically from the solid model of an object. Objects may have different kinds of surfaces e.g. planar surface, general quadratic surface, B-spline surface and compound surface. The proposed method is implemented on the AutoCAD platform. A number of produced prototypes have shown satisfactory results.published_or_final_versio

    Modeling pegylated liposomal doxorubicin-induced hand-foot syndrome and intestinal mucositis in zebrafish

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    [[abstract]]Pegylated liposomal doxorubicin (PLD) has been widely used to treat cancer. The adverse effects of PLD noted in clinical practice, especially hand-foot syndrome (HFS), are regarded as unique, and the management methods for them remain limited. This study was aimed at developing a feasible experimental model for translational medicine to solve this clinical issue by using skin fluorescent transgenic zebrafish. We established an optimal protocol for the administration of Lipo-Dox™, a PLD in current clinical use, to the Tg(k18:dsred) zebrafish line expressing red fluorescence in keratinocytes. We made use of bodyweight, survival rate, gross observation, flssuorescent microscopic assessment, and pathological examination of the zebrafish to assess this model. The consecutive administration protocol of PLD resulted in growth retardation of the zebrafish embryo and survival impairment, indicating establishment of a significant toxicity. We observed fin necrosis and keratinocyte dissociation phenotypes in the PLD-treated fish after consecutive administration. The skin toxicity induced by the Lipo-Dox injection was subsequently reversible, which might be compatible with a clinical course of skin recovery after discontinuation of Lipo-Dox administration. Furthermore, we found that the number of intestinal goblet cells, an important marker of intestinal inflammation, in the Lipo-Dox-injected zebrafish was markedly increased, accompanied by impaired mucosal integrity. The intestinal inflammation induced by Lipo-Dox resembled the intestinal mucositis the clinical patients suffered from after the administration of PLD. In conclusion, we established a zebrafish model for PLD-induced HFS. The intestinal mucositis simultaneously noted in the PLD-treated zebrafish validated the similarity of clinical courses after administration of PLD. This model is easily assessable, efficient, and worthy for use in developing a new therapeutic protocol for prevention or treatment of HFS as well as intestinal mucositis. Further clinical investigations to validate the correlation between human and zebrafish data are warranted.[[journaltype]]國外[[ispeerreviewed]]Y[[booktype]]電子版[[countrycodes]]GB

    Dynamic wavelet neural network model for forecasting returns of SHFE copper futures price

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    Session C8: P13Appropriate forecasting of commodity futures price returns is of crucial importance to achieve hedging effectiveness against the returns volatility risk. This paper presents a nonparametric dynamic recurrent wavelet neural network model for forecasting returns of Shanghai Futures Exchange (SHFE) copper futures price. The proposed model employs a wavelet basis function as the activation function for hidden-layer neurons of the neural network. The aim of this arrangement is to incorporate the fractal properties discovered in futures price return series. In the wavelet transform domain, fractal self-similarity information of the returns series over a certain time scale can be extracted. Input variables are analyzed and selected to facilitate effective forecasting. Statistical indices such as normal mean square error (NMSE) are adopted to evaluate forecasting performance of the proposed model. The forecasted result shows that dynamic wavelet neural network has good prediction properties compared with traditional linear statistical model such as ARIMA and other neural network forecasting models.published_or_final_versionThe 7th International Conference on Digital Enterprise Technology (DET 2011), Athens, Greece, 28-30 September 2011. In Proceedings of the 7th DET, 2011, p. 109-11

    CD4<sup>+</sup> T-cell plasticity in non-infectious retinal inflammatory disease

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    Non-infectious uveitis (NIU) is a potentially sight-threatening disease. Effector CD4+ T cells, especially interferon-γ-(IFNγ) producing Th1 cells and interleukin-17-(IL-17) producing Th17 cells, are the major immunopathogenic cells, as demonstrated by adoptive transfer of disease in a model of experimental autoimmune uveitis (EAU). CD4+FoxP3+CD25+ regulatory T cells (Tregs) were known to suppress function of effector CD4+ T cells and contribute to resolution of disease. It has been recently reported that some CD4+ T-cell subsets demonstrate shared phenotypes with another CD4+ T-cell subset, offering the potential for dual function. For example, Th17/Th1 (co-expressing IFNγ and IL-17) cells and Th17/Treg (co-expressing IL-17 and FoxP3) cells have been identified in NIU and EAU. In this review, we have investigated the evidence as to whether these ‘plastic CD4+ T cells’ are functionally active in uveitis. We conclude that Th17/Th1 cells are generated locally, are resistant to the immunosuppressive effects of steroids, and contribute to early development of EAU. Th17/Treg cells produce IL-17, not IL-10, and act similar to Th17 cells. These cells were considered pathogenic in uveitis. Future studies are needed to better clarify their function, and in the future, these cell subsets may in need to be taken into consideration for designing treatment strategies for disease

    Physical activity, smoking, and the incidence of clinically diagnosed insomnia

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    OBJECTIVE: This study was designed to examine the independent and combined associations of physical activity and smoking on the incidence of doctor-diagnosed insomnia using a nationally representative sample over seven years, taking into account other relevant covariates. METHODS: Participants aged 18 years or older in the 2005 Taiwan National Health Interview Survey (NHIS) with links to National Health Insurance (NHI) claim data between 2005 and 2012 and without diagnosed insomnia before 2005, were selected into this study (n = 12,728). Participants were classified as having insomnia with International Classification of Diseases, Ninth Revision (ICD-9) CM codes 307.41, 307.42, or 780.52. Self-reported smoking status and frequency, duration, and types of leisure-time and non−leisure-time physical activities were collected. Metabolic equivalent (MET) intensity levels for each activity were assigned, and weekly energy expenditure of each activity was calculated and summed. RESULTS: Inactive participants had a higher risk of incident insomnia [hazard ratio (HR) = 1.22, 95% confidence interval (CI) = 1.06–1.42, p = 0.007] than the active group, and ever-smokers were more likely to have incident insomnia than never smokers (HR = 1.45, 95% CI = 1.20–1.76, p < 0.001). Compared with the nonsmoker/active group, the ever-smoker/inactive group had a higher risk of incident insomnia (HR = 1.78, 95% CI = 1.41–2.25, p < 0.001). Sensitivity analyses excluding individuals diagnosed with other sleep disorders or mental disorders yielded similar results, with the ever-smoker/inactive group having the highest risk of insomnia. CONCLUSIONS: Inactive adults and smokers are at higher risk for incident insomnia, highlighting the importance of a healthy lifestyle and pointing to strategies such as encouraging smoking cessation and physical activity to avoid insomnia among adults

    Prospective association between late-life physical activity and hospital care utilisation: a 7-year nationwide follow-up study

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    BACKGROUND: It is still equivocal whether there is a potential role of late-life physical activity in ameliorating the challenges of increasing healthcare expenditure due to the consequence of global population ageing. OBJECTIVE: this study aimed to examine the prospective association between physical activity and subsequent hospital care utilisation in older adults and to explore the optimal dose of physical activity required to reduce hospital care utilisation. DESIGN: this was a prospective cohort study based on the data from the Taiwan 2005 National Health Interview Survey, which were linked to the 2005-12 claims data from the National Health Insurance system. PARTICIPANTS: 1,760 older adults aged 65 or more. METHODS: the frequency, duration and intensity for physical activity were assessed, and total physical activity energy expenditure was estimated. The average annualised hospital care utilisation for the period 2006 through 2012, including number of hospitalisations, number of days in hospital and the costs of hospitalisation, were calculated. RESULTS: older adults engaging in at least moderate volume of physical activity (≥1,000 kcal/week) experienced fewer subsequent hospital admissions and fewer days in hospital than did sedentary individuals, after adjusting for covariates. Trends for reduced hospitalisation costs were also found. These associations persisted in sensitivity analyses, including tests of reverse causation. CONCLUSION: this study has provided evidence that older adults who are at least moderately active may minimise utilisation of hospital care services. The findings highlight the importance of maintaining a physically active lifestyle in later life

    A variational approach for dissipative quantum transport in a wide parameter space

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