472 research outputs found

    Multifractal behavior of linear polymers in disordered media

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    The scaling behavior of linear polymers in disordered media modelled by self-avoiding random walks (SAWs) on the backbone of two- and three-dimensional percolation clusters at their critical concentrations p_c is studied. All possible SAW configurations of N steps on a single backbone configuration are enumerated exactly. We find that the moments of order q of the total number of SAWs obtained by averaging over many backbone configurations display multifractal behavior, i.e. different moments are dominated by different subsets of the backbone. This leads to generalized coordination numbers \mu_q and enhancement exponents \gamma_q, which depend on q. Our numerical results suggest that the relation \mu_1 = p_ c \mu between the first moment \mu_1 and its regular lattice counterpart \mu is valid.Comment: 11 pages, 12 postscript figures, to be published in Phys. Rev.

    Machine Learning in Automated Text Categorization

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    The automated categorization (or classification) of texts into predefined categories has witnessed a booming interest in the last ten years, due to the increased availability of documents in digital form and the ensuing need to organize them. In the research community the dominant approach to this problem is based on machine learning techniques: a general inductive process automatically builds a classifier by learning, from a set of preclassified documents, the characteristics of the categories. The advantages of this approach over the knowledge engineering approach (consisting in the manual definition of a classifier by domain experts) are a very good effectiveness, considerable savings in terms of expert manpower, and straightforward portability to different domains. This survey discusses the main approaches to text categorization that fall within the machine learning paradigm. We will discuss in detail issues pertaining to three different problems, namely document representation, classifier construction, and classifier evaluation.Comment: Accepted for publication on ACM Computing Survey

    FAULT DIAGNOSIS OF INDUCTION MOTOR USING PLC

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    ABSTRACT: Induction motors are used in many industrial applications in a wide range of operating areas as they have simple and robust structure, and low production costs. Induction motors are now being used more as compared to before due to their certain advantages such as versatility, dependability and economy, good self-starting capability, offers users simple, rugged construction easy maintenance, low cost and reliability. The reliability of an induction motor is of great Importance in industrial as well as commercial, aerospace and military applications. Also the knowledge about fault mode behavior of an induction motor drive system is extremely important from the standpoint of improved system design, protection, and fault tolerant control. [1] In this paper different problems are dealt, such as overvoltage, over current , over temperature, over speed, inrush current, vibration monitoring which are being faced by IM's during it's course of operation. There are various methods for fault detection and protection of IM. Some of them are On-line fault detection, Stator fault monitoring techniques, Microcontrollers based protection system and Programmable Logic Controller (PLC) based protection system. In this study, the method used is PLC based protection system of IM

    New Pharmacological Agents to Aid Smoking Cessation and Tobacco Harm Reduction: What has been Investigated and What is in the Pipeline?

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    A wide range of support is available to help smokers to quit and aid attempts at harm reduction, including three first-line smoking cessation medications: nicotine replacement therapy, varenicline and bupropion. Despite the efficacy of these, there is a continual need to diversify the range of medications so that the needs of tobacco users are met. This paper compares the first-line smoking cessation medications to: 1) two variants of these existing products: new galenic formulations of varenicline and novel nicotine delivery devices; and 2) twenty-four alternative products: cytisine (novel outside of central and eastern Europe), nortriptyline, other tricyclic antidepressants, electronic cigarettes, clonidine (an anxiolytic), other anxiolytics (e.g. buspirone), selective 5-hydroxytryptamine (5-HT) reuptake inhibitors, supplements (e.g. St John’s wort), silver acetate, nicobrevin, modafinil, venlafaxine, monoamine oxidase inhibitors (MAOI), opioid antagonist, nicotinic acetylcholine receptors (nAChR) antagonists, glucose tablets, selective cannabinoid type 1 receptor antagonists, nicotine vaccines, drugs that affect gamma-aminobutyric acid (GABA) transmission, drugs that affect N-methyl-D-aspartate receptors (NMDA), dopamine agonists (e.g. levodopa), pioglitazone (Actos; OMS405), noradrenaline reuptake inhibitors, and the weight management drug lorcaserin. Six criteria are used: relative efficacy, relative safety, relative cost, relative use (overall impact of effective medication use), relative scope (ability to serve new groups of patients), and relative ease of use (ESCUSE). Many of these products are in the early stages of clinical trials, however, cytisine looks most promising in having established efficacy and safety and being of low cost. Electronic cigarettes have become very popular, appear to be efficacious and are safer than smoking, but issues of continued dependence and possible harms need to be considered

    Serotonin-Norepinephrine Reuptake Inhibitors for Pain Control: Premise and Promise

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    The precise mechanisms of pain perception and transmission in the central nervous system have not been fully elucidated. However, extensive data support a role for the monoamine neurotransmitters, serotonin and norepinephrine, in the modulation of pain. Experiments with animal models of pain indicate that noradrenergic interventions, and to a lesser extent serotonergic interventions, reduce pain-related behavior. This is supported by data from clinical trials in humans in which antidepressants have been shown to reduce pain and functional impairment in central and neuropathic pain conditions. These effects are particularly well-studied in trials with serotonin-norepinephrine reuptake inhibitors (SNRIs), which have provided a useful tool in the clinician’s arsenal, particularly considering the limitations of other classes of pain medications such as opioids, anti-inflammatories, and anticonvulsants (i.e., limited efficacy, safety and tolerability issues). Moreover, painful physical symptoms are frequently comorbid with major psychiatric disorders such as major depressive disorder and anxiety disorders. This paper reviewed and summarized the rationale and potential role of SNRIs for the control of pain including clinical and preclinical background. Currently evidence does not definitely support a role of the SNRIs, while limited data propose a putative promise of SNRIs in the treatment of pain related disorders including fibromyalgia and depressed patients with multiple somatic complaints. More researches are warranted to generalize currently available preliminary evidences

    Cognitive modeling of mindfulness therapy by autogenic training

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    In this paper, the effect of a mindfulness therapy based on a Network-Oriented Modeling approach is addressed. The considered therapy is Autogenic Training that can be used when under stress; it has as two main goals to achieve feeling heavy and warm body parts (limbs). Mantras have been used in therapies since long ago to make stressed individuals more relaxed, and they are also used in Autogenic Training. The presented cognitive temporal-causal network model addresses the modeling of Autogenic Training asking this into account. In the first phase a strong stress-inducing stimulus causes the individual to develop an extreme stressful emotion. In the second phase, the therapy with the two goals is shown to make the stressed individual relaxed. Hebbian learning is used to increase the influence of the therapy.</p

    Defects in NK cell immunity of pediatric cancer patients revealed by deep immune profiling

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    Systemic immunity plays an important role in cancer immune surveillance and response to therapy, but little is known about the immune status of children with solid cancers. We performed a high-dimensional single-cell analysis of systemic immunity in 50 treatment-naïve pediatric cancer patients, comparing them to age-matched healthy children. Children with cancer had a lower frequency of peripheral NK cells, which was not due to tumour sequestration, had lower surface levels of activating receptors and increased levels of the inhibitory NKG2A receptor. Furthermore, the NK cells of pediatric cancer patients were less mature and less cytotoxic when tested in vitro. Culture of these NK cells with interleukin-2 restored their cytotoxicity. Collectively, our data show that NK cells in pediatric cancer patients are impaired through multiple mechanisms and identifies rational strategies to restore their functionality

    STUDIES OF ULTRASONIC AND VISCOMETRIC BEHAVIOR OF AZITHROMYCIN WITH DIFFERENT SOLVENT SYSTEMS DIOXANE-WATER AND METHANOL-WATER MIXTURE AT 305.15 K

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    ABSTRACT Antibiotic drug Azithromycin is mainly used for treatments of infectious disease caused by bacteria such as respiratory,skin,ear and sexually transmitted diseases such great importance of azithromycine in human life the densities, ultrasonic velocities and viscosities of azithromycine have been evaluated in different concentrations in 70% dioxane-water and 70% methanol-water mixtures at 305.15 K. Experimental data of sound velocities and densities of solutions in 70% dioxane-water helps to determine the various acoustical parameters such as adiabatic compressibility, apparent molal volumes, intermolecular free length, specific acoustic impedance, relative association etc. for evaluating the molecular interactions present in different solutions were studied. Keywords: Azithromycin drug, dioxane water and viscometric measurements. INTRODUCTION In the fields of medicinal, industrial, biochemistry etc the study of molecular interactions between solutes molecule and solvent media has got great importance. It also helps the study of solute solvent and solventsolvent interactions can by the measurement of relative viscosity and ultrasonic velocity of an electrolyte in solutions EXPERIMENTAL SECTION The chemicals used were of AR grade and were purified by standard methods. Requisite amount of chemicals weighing was done by using electronic balance.By using the Pyknometers the densities of solutions were determined, which was standardized by the standard procedure. Ostwald&apos;s Viscometer was used for measurements of viscosity which was kept in elite thermostatic water bath (±0.1°C). The ultrasonic velocity of solution and solvent was determined by using single crystal interferometer (Mittal Enterprises, Model F-81) with accuracy of ± 0.03% and 2 MHz frequency. RESULTS AND DISCUSSION Acoustic parameters, densities and relative viscosities have been determined for all the solutions and were calculated by using different equations 14 and are presented in the followin
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