721 research outputs found

    Multisource Bayesian sequential change detection

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    Suppose that local characteristics of several independent compound Poisson and Wiener processes change suddenly and simultaneously at some unobservable disorder time. The problem is to detect the disorder time as quickly as possible after it happens and minimize the rate of false alarms at the same time. These problems arise, for example, from managing product quality in manufacturing systems and preventing the spread of infectious diseases. The promptness and accuracy of detection rules improve greatly if multiple independent information sources are available. Earlier work on sequential change detection in continuous time does not provide optimal rules for situations in which several marked count data and continuously changing signals are simultaneously observable. In this paper, optimal Bayesian sequential detection rules are developed for such problems when the marked count data is in the form of independent compound Poisson processes, and the continuously changing signals form a multi-dimensional Wiener process. An auxiliary optimal stopping problem for a jump-diffusion process is solved by transforming it first into a sequence of optimal stopping problems for a pure diffusion by means of a jump operator. This method is new and can be very useful in other applications as well, because it allows the use of the powerful optimal stopping theory for diffusions.Comment: Published in at http://dx.doi.org/10.1214/07-AAP463 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Robust adaptive sampled-data control of a class of systems under structured nonlinear perturbations

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    Cataloged from PDF version of article.A robust adaptive sampled-data feedback stabilization scheme is presented for a class of systems with nonlinear additive perturbations. The proposed controller generates a control input by using high-gain static or dynamic feedback from nonuniform sampled values of the output. A simple adaptation rule adjusts the gain and the sampling period of the controller

    Robust stability of discrete time systems under parametric perturbations

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    Cataloged from PDF version of article.Stability robustness analysis of a system under parametric perturbations is concerned with characterizing a region in the parameter space in which the system remains stable. In this paper, two methods are presented to estimate the stability robustness region of a linear, time-invariant, discrete-time system under multiparameter additive perturbations. An inherent difficulty, which originates from the nonlinear appearance of the perturbation parameters in the inequalities defining the robustness region, is resolved by transforming the problem to stability of a higher order continuous-time system. This allows for application of the available results on stability robustness of continuous-time systems to discrete-time systems. The results are also applied to stability analysis of discrete-time interconnected systems, where the interconnections are treated as perturbations on decoupled stable subsystems

    Kaposi's Sarcoma following Chronic Lymphocytic Leukemia: A Rare Entity

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    Cutaneous manifestations can occur in the wide range of internal malignancy. They can occur by metastases or local spread, direct infiltration, or a site of primary malignancy itself. Sometimes these manifestations are related with an underlying malignancy but they do not contain malignant cells as paraneoplastic dermatological syndromes. Chronic lymphocytic leukemia (CLL) is the most common leukemia all over the world. Cutaneous lesions occur in up to 25% of patients. Most commonly seen cutaneous lesions in CLL are those of infectious or hemorrhagic origin. Skin cancer risk was also increased eightfold in CLL when compared with normal population, so cutaneous lesions in CLL can be the first manifestation of secondary skin malignancy. Herein, we report an interesting case of Kaposi's sarcoma which was diagnosed during the course of CLL

    Robust adaptive sampled-data control of a class of systems under structured nonlinear perturbations

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    A robust adaptive sampled-data feedback stabilization scheme is presented for a class of systems with nonlinear additive perturbations. The proposed controller generates a control input by using high-gain static or dynamic feedback from nonuniform sampled values of the output. A simple adaptation rule adjusts the gain and the sampling period of the controller

    Use of Lactobacillus farciminis to improve antioxidant status of Tuj lambs

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    The aim of this study was to investigate the effects of Lactobacillus farciminis on growth traits and antioxidant status in preweaning and postweaning Tuj lambs. Twenty lambs were divided into four groups, regardless of gender, with a mean live weight of 7.81 ± 0.50 kg. At the start of the experiment, the average age of the lambs was seven days. During the six-week preweaning period, control (C) lambs were fed with colostrum only, and Lactobacillus farciminis was given orally to the treated lambs at 1 g/day/lamb (L1), 2 g/day/lamb (L2) or 4 g/day/lamb (L3). The experiment continued for a total of 22 weeks. During the first six weeks, bodyweight (BW) increased significantly in L1 at the sixth week. Also during this period, bodyweight gain (BWG) in L2 at 2 - 3 weeks and in L3 at 5 - 6 weeks differed from C. In the subsequent period, BW and BWG were not affected by probiotic supplementation. The effects of probiotic supplementation on malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were significant throughout the experiment, with the effect on glutathione (GSH) also being important in the first six weeks. Thus, Lactobacillus farciminis provided orally to Tuj breed lambs could be used to improve their antioxidant status without compromising growth

    Close Binary System GO Cyg

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    In this study, we present long term photometric variations of the close binary system \astrobj{GO Cyg}. Modelling of the system shows that the primary is filling Roche lobe and the secondary of the system is almost filling its Roche lobe. The physical parameters of the system are M1=3.0±0.2M⊙M_1 = 3.0\pm0.2 M_{\odot}, M2=1.3±0.1M⊙M_2 = 1.3 \pm 0.1 M_{\odot}, R1=2.50±0.12R⊙R_1 = 2.50\pm 0.12 R_{\odot}, R2=1.75±0.09R⊙R_2 = 1.75 \pm 0.09 R_{\odot}, L1=64±9L⊙L_1 = 64\pm 9 L_{\odot}, L2=4.9±0.7L⊙L_2 = 4.9 \pm 0.7 L_{\odot}, and a=5.5±0.3R⊙a = 5.5 \pm 0.3 R_{\odot}. Our results show that \astrobj{GO Cyg} is the most massive system near contact binary (NCB). Analysis of times of the minima shows a sinusoidal variation with a period of 92.3±0.592.3\pm0.5 years due to a third body whose mass is less than 2.3M⊙M_{\odot}. Finally a period variation rate of −1.4×10−9-1.4\times10^{-9} d/yr has been determined using all available light curves.Comment: Accepted for publication in New Astronomy, 18 pages, 4 figures, 7 table

    Novel renal replacement strategies for the elimination of serum free light chains in patients with kappa light chain nephropathy

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    Multiple myeloma (MM) is a malignancy with excessive production of monoclonal proteins. At disease presentation 30% of MM patients have significant renal impairment which may progress to renal failure requiring dialysis. Besides chemotherapy extracorporeal elimination procedures such as plasma exchange have been applied as adjuvant strategies to eliminate free light chains from circulating blood, however the efficacy was poor with older techniques. We report about a highly efficient method to eliminate serum free light chain (sFLC) using a newly designed protein leaking membrane in patients suffering from sFLC induced acute renal failure. The protein leaking membrane (HCO 1100) is characterized by increased pore size facilitating elimination of middle molecules such as sFLC kappa (22.5 kD). The HCO 1100 membrane was applied in a hemodialysis and hemodiafiltration mode and compared to standard procedures (high flux hemodialysis, hemodiafiltration and plasma exchange). Hemodiafiltration with the protein leaking membrane HCO 1100 was superior to all other extracorporeal replacement strategies in eliminating sFLC-kappa from circulating blood. A median blood reduction rate of 40.8% (range 13.9% - 66.4%) was achieved during hemodiafiltration. The corresponding peak clearance rate was 25 ml/min. Importantly, the poorest elimination rate was achieved by plasma exchange followed by standard high flux hemodialysis. Extracorporeal elimination strategies with the protein leaking membrane HCO 1100 may be a promising adjuvant treatment strategy for patients with sFLC nephropathy requiring dialysis. Hemodiafiltration and to lesser extend also hemodialysis with the HCO 1100 hemofilter are able to eliminate substantial amounts of sFLC kappa in MM patients
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