987 research outputs found

    Continuous Uniform Finite Time Stabilization of Planar Controllable Systems

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    Continuous homogeneous controllers are utilized in a full state feedback setting for the uniform finite time stabilization of a perturbed double integrator in the presence of uniformly decaying piecewise continuous disturbances. Semiglobal strong C1\mathcal{C}^1 Lyapunov functions are identified to establish uniform asymptotic stability of the closed-loop planar system. Uniform finite time stability is then proved by extending the homogeneity principle of discontinuous systems to the continuous case with uniformly decaying piecewise continuous nonhomogeneous disturbances. A finite upper bound on the settling time is also computed. The results extend the existing literature on homogeneity and finite time stability by both presenting uniform finite time stabilization and dealing with a broader class of nonhomogeneous disturbances for planar controllable systems while also proposing a new class of homogeneous continuous controllers

    The Involvement of Urinary Kallikrein in the Renal Escape from the Sodium Retaining Effect of Mineralocorticoids

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    It is well known that the normal kidney escapes the sodium retaining effect of mineralocorticoids. However, the mechanism that mediates this escape is not understood. The possible role of kallikrein in this escape phenomenon was investigated by placing seven dogs in metabolic cages and giving them a constant sodium diet. After they had been on this diet three days, urine was collected for two 24-hour periods. DOCA (25 mg/day) was then given intramuscularly for five days. Urine was collected daily during this DOCA period and for two additional 24- hour periods. Urine volume, sodium, potassium, protein, and kallikrein excretion were then measured. Urinary kallikrein increased from 251.9 ± 34.8 (mean ± SE) in the second day of the control period to 639.8 ± 110.1 IJ-g/day (P \u3c .01) by the third day of treatment. It remained elevated two days after DOCA was discontinued. Sodium excretion decreased significantly on the first day of DOCA treatment, returning to the previous values thereafter. Urine protein excretion remained constant. The enhanced urinary kallikrein during the escape suggests that the kallikrein system could be involved in the regulation of sodium metabolism by acting as a natriuretic factor, or perhaps by regulating the renal blood flow

    Direct observation of 4+ to 2+ gamma transition in 8Be

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    The low lying states in 8^8Be are believed to have a two-alpha cluster structure and hence a large intrinsic quadrupole deformation. An earlier calculation showed a large collective enhancement in gamma transition probability between the low lying states leading to a 4+^+ to 2+^+ gamma branch of 107\sim10^{-7} and a resonant radiative cross section of 134 nb for the α+α\alpha+\alpha entrance channel. We report here the first experimental evidence for this transition through a γαα\gamma-\alpha-\alpha coincidence measurement in the reaction 4^4He(α,αγ\alpha,\alpha \gamma)4^4He using a gas target. The measured cross sections on and off the 4+^+ resonance are 165 ±\pm 41 (stat) ±\pm35 (sys) nb and 39 ±\pm 25 (stat) ±\pm7 (sys) nb, respectively.Comment: Total 4 pages, 4 figures, in RevTeX format, submitted to PR

    Electron-Phonon Resonance in some New Charge Transfer Complexes

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    Improving adaptive bagging methods for evolving data streams

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    We propose two new improvements for bagging methods on evolving data streams. Recently, two new variants of Bagging were proposed: ADWIN Bagging and Adaptive-Size Hoeffding Tree (ASHT) Bagging. ASHT Bagging uses trees of different sizes, and ADWIN Bagging uses ADWIN as a change detector to decide when to discard underperforming ensemble members. We improve ADWIN Bagging using Hoeffding Adaptive Trees, trees that can adaptively learn from data streams that change over time. To speed up the time for adapting to change of Adaptive-Size Hoeffding Tree (ASHT) Bagging, we add an error change detector for each classifier. We test our improvements by performing an evaluation study on synthetic and real-world datasets comprising up to ten million examples

    Triple-Negative Breast Cancer: A Review of Conventional and Advanced Therapeutic Strategies

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    Triple-negative breast cancer (TNBC) cells are deficient in estrogen, progesterone and ERBB2 receptor expression, presenting a particularly challenging therapeutic target due to their highly invasive nature and relatively low response to therapeutics. There is an absence of specific treatment strategies for this tumor subgroup, and hence TNBC is managed with conventional therapeutics, often leading to systemic relapse. In terms of histology and transcription profile these cancers have similarities to BRCA-1-linked breast cancers, and it is hypothesized that BRCA1 pathway is non-functional in this type of breast cancer. In this review article, we discuss the different receptors expressed by TNBC as well as the diversity of different signaling pathways targeted by TNBC therapeutics, for example, Notch, Hedgehog, Wnt/b-Catenin as well as TGF-beta signaling pathways. Additionally, many epidermal growth factor receptor (EGFR), poly (ADP-ribose) polymerase (PARP) and mammalian target of rapamycin (mTOR) inhibitors effectively inhibit the TNBCs, but they face challenges of either resistance to drugs or relapse. The resistance of TNBC to conventional therapeutic agents has helped in the advancement of advanced TNBC therapeutic approaches including hyperthermia, photodynamic therapy, as well as nanomedicine-based targeted therapeutics of drugs, miRNA, siRNA, and aptamers, which will also be discussed. Artificial intelligence is another tool that is presented to enhance the diagnosis of TNBC
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