2,511 research outputs found

    Low uptake of antiretroviral therapy after admission with human immunodeficiency virus and tuberculosis in KwaZulu-Natal, South Africa.

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    A prospective cohort study was conducted among human immunodeficiency virus (HIV) infected in-patients with tuberculosis (TB) or other opportunistic infections (OIs) in South Africa to estimate subsequent antiretroviral therapy (ART) uptake and survival

    Von Bertalanffy's dynamics under a polynomial correction: Allee effect and big bang bifurcation

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    In this work we consider new one-dimensional populational discrete dynamical systems in which the growth of the population is described by a family of von Bertalanffy's functions, as a dynamical approach to von Bertalanffy's growth equation. The purpose of introducing Allee effect in those models is satisfied under a correction factor of polynomial type. We study classes of von Bertalanffy's functions with different types of Allee effect: strong and weak Allee's functions. Dependent on the variation of four parameters, von Bertalanffy's functions also includes another class of important functions: functions with no Allee effect. The complex bifurcation structures of these von Bertalanffy's functions is investigated in detail. We verified that this family of functions has particular bifurcation structures: the big bang bifurcation of the so-called "box-within-a-box" type. The big bang bifurcation is associated to the asymptotic weight or carrying capacity. This work is a contribution to the study of the big bang bifurcation analysis for continuous maps and their relationship with explosion birth and extinction phenomena.info:eu-repo/semantics/publishedVersio

    The Trembling Hand Approach to Automata in Iterated Games

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    We consider two state automata playing infinitely iterated two players, two strategies game, where each move can be mis-implemented (or mis-perceived) with a small error probability, and compute the payoff matrix by means of a perturbation approach. Keywords: Alternating Prisoner's Dilemma, Perturbed Payoff, Repeated Games, Simultaneous Prisoner's Dilemma

    Molecular characterization of resistance to rifampicin in clinical isolates of Neisseria meningitidis

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    AbstractAmong 3904 meningococcal isolates collected between October 2002 and June 2007 by the French Meningococcal Reference Centre, eight (0.20%) were resistant to rifampicin (Rif-R; MIC >1 mg/L) and 27 (0.69%) were intermediate-resistant to rifampicin (Rif-I; MICs between 0.38 mg/L and 1 mg/L) according to the E-test method. The MICs determined by agar dilution were lower, eliminating the E-test intermediate category. All Rif-R isolates had mutations in the rpoB gene, resulting in substitutions at or near amino acid position 552, which were absent in non-resistant isolates. These data suggest that a rifampicin clinical breakpoint of 1.0 mg/L should be adopted for Neisseria meningitidis

    Empirical and experimental perspectives on big data in recommendation systems: a comprehensive survey

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    This survey paper provides a comprehensive analysis of big data algorithms in recommendation systems, addressing the lack of depth and precision in existing literature. It proposes a two-pronged approach: a thorough analysis of current algorithms and a novel, hierarchical taxonomy for precise categorization. The taxonomy is based on a tri-level hierarchy, starting with the methodology category and narrowing down to specific techniques. Such a framework allows for a structured and comprehensive classification of algorithms, assisting researchers in understanding the interrelationships among diverse algorithms and techniques. Covering a wide range of algorithms, this taxonomy first categorizes algorithms into four main analysis types: user and item similarity based methods, hybrid and combined approaches, deep learning and algorithmic methods, and mathematical modeling methods, with further subdivisions into sub-categories and techniques. The paper incorporates both empirical and experimental evaluations to differentiate between the techniques. The empirical evaluation ranks the techniques based on four criteria. The experimental assessments rank the algorithms that belong to the same category, sub-category, technique, and sub-technique. Also, the paper illuminates the future prospects of big data techniques in recommendation systems, underscoring potential advancements and opportunities for further research in this fields

    Variation in morphology and branching pattern of superior mesenteric artery

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    The anatomical variations of superior mesenteric artery branches are common. In this study we reported an extraordinary morphology and branching of superior mesenteric artery, during our routine dissection of a 38-year-old Sudanese male cadaver, where the superior mesenteric artery forms an arch over the confluence of inferior vena cava and left renal vein. Other variations observed were: 1) The superior mesenteric artery shares the same origin of coeliac trunk; 2) The unusual origin of right hepatic artery. We think that the knowledge of these variations plays an important role in conducting and planning of radiological and surgical procedures especially in hepatobiliary and pancreatic surgery. Morphology and branching patterns of this artery is anecdotic, which makes this case the most unique

    A comprehensive survey of text classification techniques and their research applications: observational and experimental insights

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    The exponential growth of textual data presents substantial challenges in management and analysis, notably due to high storage and processing costs. Text classification, a vital aspect of text mining, provides robust solutions by enabling efficient categorization and organization of text data. These techniques allow individuals, researchers, and businesses to derive meaningful patterns and insights from large volumes of text. This survey paper introduces a comprehensive taxonomy specifically designed for text classification based on research fields. The taxonomy is structured into hierarchical levels: research field-based category, research field-based sub-category, methodology-based technique, methodology sub-technique, and research field applications. We employ a dual evaluation approach: empirical and experimental. Empirically, we assess text classification techniques across four critical criteria. Experimentally, we compare and rank the methodology sub-techniques within the same methodology technique and within the same overall research field sub-category. This structured taxonomy, coupled with thorough evaluations, provides a detailed and nuanced understanding of text classification algorithms and their applications, empowering researchers to make informed decisions based on precise, field- specific insights

    Reconnection and acoustic emission of quantized vortices in superfluid by the numerical analysis of the Gross-Pitaevskii equation

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    We study numerically the reconnection of quantized vortices and the concurrent acoustic emission by the analysis of the Gross-Pitaevskii equation. Two quantized vortices reconnect following the process similar to classical vortices; they approach, twist themselves locally so that they become anti-parallel at the closest place, reconnect and leave separately.The investigation of the motion of the singular lines where the amplitude of the wave function vanishes in the vortex cores confirms that they follow the above scenario by reconnecting at a point. This reconnection is not contradictory to the Kelvin's circulation theorem, because the potential of the superflow field becomes undefined at the reconnection point. When the locally anti-parallel part of the vortices becomes closer than the healing length, it moves with the velocity comparable to the sound velocity, emits the sound waves and leads to the pair annihilation or reconnection; this phenomena is concerned with the Cherenkov resonance. The vortices are broken up to smaller vortex loops through a series of reconnection, eventually disappearing with the acoustic emission. This may correspond to the final stage of the vortex cascade process proposed by Feynman. The change in energy components, such as the quantum, the compressible and incompressible kinetic energy is analyzed for each dynamics. The propagation of the sound waves not only appears in the profile of the amplitude of the wave function but also affects the field of its phase, transforming the quantum energy due to the vortex cores to the kinetic energy of the phase field.Comment: 11 pages, 16 figures, LaTe

    Effect of Nano-Silica on The Thermo-Physical Properties of the Thermal Eutectic (Na0.6K0.4)NO3 System

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    Here, we investigate the effect of adding nano-silica particles on the thermo-physical properties of the (Na0.6K0.4)NO3 based thermal energy storage systems. Five different systems tagged as M00, M01, M02, M03 and M04, with different nano-silica percentage of 0, 1, 2, 3, and 4 wt%, respectively, were prepared. Various experimental techniques were employed to study the thermo-physical properties of the systems during (solid-solid) phase P1, (solid-liquid) phase P2 and (liquid-solid) phase P3, and to clarify the effect of nano-silica on the thermal energy storage efficiency during both charging and discharging processes. According to the Differential Scanning Calorimeter (DSC) thermal analysis, it was found that the system M02 whose nano-silica addition rate of 2 wt%, has the most favorable thermal characteristics (i.e., highest specific heat and lowest enthalpy change). Moreover, the addition of 2 wt% represents the optimum distribution of nano-silica inside the principal base system M00. This leads to an improvement in the porosity of the system due to the degree of homogeneity caused by the thermophoresis effect distribution, the high surface area of the nano-silica with the activity of the M00 matrix alongside the degree of the alkalinity of nano-silica. Besides, the electric conductivity measurements showed that the 2wt% percentage is the optimum one for thermal energy storage systems

    HYPOLIPIDEMIC AND ANTI-FATTY LIVER EFFECTS EXERTED BY STANDARDIZED PUNICA GRANATUM L. PEEL EXTRACT IN HEPG2 CELL-LINE AND HIGH-FAT DIET-INDUCED MICE

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    Objective: Pomegranate, (Punica granatum L., Lythraceae) peel has concentrated amounts of lipid-lowering elements that demonstrated, in various hoary and recent studies, their effects against obesity and hyperlipidemia, which involves elevated rates of lipid and lipoprotein levels in blood and increases risks of cardiovascular diseases.We aim to study expression modulation of genes involved in lipid metabolism by the impact of standardized pomegranate peel extract (PPE) in a comprehensive research on human liver cells and experimental mice.Methods: Using reverse-transcription real-time PCR, an in vitro study harnessing HepG2 cell line was conducted to determine the hyperlipidemia-related gene expression profiles and cytotoxic effects upon treatment with PPE. In another complementary in vivo study, male C57BL/6J mice were fed a high-fat diet (HFD) or an HFD supplemented with PPE for 14 d to define the expression of lipid metabolism related genes that control obesity. Fatty liver proportions were also estimated after treatment.Results: Higher mRNA expression of LDL receptor (LDL-R) and down-regulation of sterol regulatory element-binding protein (SREBF-2), (SRBEP-1c), Fatty acid synthase (FAS) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) upon PPE treatment in HepG2 cell line were significantly recorded. In vivo study indicated significant weight reduction of body and liver, besides amelioration of fatty liver state detected by histological analysis. Moreover, the reverse-transcription real-time PCR assay demonstrated suppression (FAS) expression and up regulation of hormone sensitive lipase (HSL) in mice isolated liver and white adipose tissues.Conclusion: Our study manages to affirm the hypolipidemic and anti-fatty liver influence of Punica granatum L. peel extract, reflected by molecular evaluation above and beyond other physiological assays.Keywords: Pomegranate, Peel extract, Hyperlipidemia, LDLR, SREBP, FAS, HMGCR, HS
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