317 research outputs found

    Massive Assymetrical Virginal Breast Hypertrophy: A Case Report

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    Virginal breast hypertrophy (VHB) is a rare , distinct disorder of unknown etiology with the rapid onset of macromastia at the onset of puberty.We reported a 12 year old, peripubertal girl presented to us with abnormal assymetrical growth of her breasts in 10 months. Due to the enormous breast volume, which caused her physical and psychological problems, she curtailed her social life. On examination, left breast was enlarged more in comparision to right, with associated skin changes. Endocrinological investigations were normal. A bilateral reduction mammaplasty with free nipple graft was performed. Histological analysis of the breast tissue revealed the diagnosis of virginal hypertrophy. During the follow-up period of 13 months, no recurrence was noted and patient is physically and psychologically satisfied

    Nonrelativistic Chern-Simons Vortices on the Torus

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    A classification of all periodic self-dual static vortex solutions of the Jackiw-Pi model is given. Physically acceptable solutions of the Liouville equation are related to a class of functions which we term Omega-quasi-elliptic. This class includes, in particular, the elliptic functions and also contains a function previously investigated by Olesen. Some examples of solutions are studied numerically and we point out a peculiar phenomenon of lost vortex charge in the limit where the period lengths tend to infinity, that is, in the planar limit.Comment: 25 pages, 2+3 figures; improved exposition, corrected typos, added one referenc

    Bias-voltage dependence of the magneto-resistance in ballistic vacuum tunneling: Theory and application to planar Co(0001) junctions

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    Motivated by first-principles results for jellium and by surface-barrier shapes that are typically used in electron spectroscopies, the bias voltage in ballistic vacuum tunneling is treated in a heuristic manner. The presented approach leads in particular to a parameterization of the tunnel-barrier shape, while retaining a first-principles description of the electrodes. The proposed tunnel barriers are applied to Co(0001) planar tunnel junctions. Besides discussing main aspects of the present scheme, we focus in particular on the absence of the zero-bias anomaly in vacuum tunneling.Comment: 19 pages with 8 figure

    Orthogonal methods based ant colony search for solving continuous optimization problems

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    Research into ant colony algorithms for solving continuous optimization problems forms one of the most significant and promising areas in swarm computation. Although traditional ant algorithms are designed for combinatorial optimization, they have shown great potential in solving a wide range of optimization problems, including continuous optimization. Aimed at solving continuous problems effectively, this paper develops a novel ant algorithm termed "continuous orthogonal ant colony" (COAC), whose pheromone deposit mechanisms would enable ants to search for solutions collaboratively and effectively. By using the orthogonal design method, ants in the feasible domain can explore their chosen regions rapidly and e±ciently. By implementing an "adaptive regional radius" method, the proposed algorithm can reduce the probability of being trapped in local optima and therefore enhance the global search capability and accuracy. An elitist strategy is also employed to reserve the most valuable points. The performance of the COAC is compared with two other ant algorithms for continuous optimization of API and CACO by testing seventeen functions in the continuous domain. The results demonstrate that the proposed COAC algorithm outperforms the others

    Scalar brane backgrounds in higher order curvature gravity

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    We investigate maximally symmetric brane world solutions with a scalar field. Five-dimensional bulk gravity is described by a general lagrangian which yields field equations containing no higher than second order derivatives. This includes the Gauss-Bonnet combination for the graviton. Stability and gravitational properties of such solutions are considered, and we particularily emphasise the modifications induced by the higher order terms. In particular it is shown that higher curvature corrections to Einstein theory can give rise to instabilities in brane world solutions. A method for analytically obtaining the general solution for such actions is outlined. Genericaly, the requirement of a finite volume element together with the absence of a naked singularity in the bulk imposes fine-tuning of the brane tension. A model with a moduli scalar field is analysed in detail and we address questions of instability and non-singular self-tuning solutions. In particular, we discuss a case with a normalisable zero mode but infinite volume element.Comment: published versio

    Southern Europeans in France: Invisible Migrants?

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    France fared relatively well at the start of the current economic crisis, but has experienced low economic growth and high unemployment rates in the recent years. As a result it has been a less popular destination with Southern Europeans and EU migrants in general in search of economic opportunities. Although their numbers have increased and represent a growing proportion of recent flows to France, they remain low compared to numbers observed in Germany and the UK. Despite this statistical reality, EU mobility and more generally the role of the EU in economic and social policy have been at the forefront of debates in France since the start of the 2000s, thus well before the start of the crisis. These debates have focused on two populations – the Roma and posted workers – with both groups being portrayed as threats to the French welfare state. Although posted workers are not migrants, according to official EU definitions, their characteristics and experiences are similar to other groups of temporary migrant workers. Southern Europeans account for an increasing number of posted workers, and although they have not been the primary nationalities targeted in discussions concerning this issue, the debates and policy changes introduced in the recent years concern them as well. Moreover, we argue that the focusing of political debates on other populations in France has contributed to the relative invisibility of Southern European immigrants in this country

    Poboljšana elektromagnetska kompatibilnost (EMC) sklopnog energetskog pretvarača sa slučajnom modulacijom

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    This paper surveys some analytical and experimental results concerning different randomized modulation strategies in switched-mode power converters (SMPCs). After a short review of practical experiences within the literature it presents the benefits of several randomized schemes for power converters (i.e. reduced electromagnetic interference - EMI, and lower acoustic noise). It also introduces the mathematical background for dealing with randomized modulation within the medium-frequency range: power spectrum density (PSD). Finally, the EMI measurements confirm the improved EMC performances of the randomized boost rectifier, as also in the DC-DC buck converter.Ovaj članak istražuje analitičke i eksperimentalne rezultate različitih slučajnih strategija modulacije u sklopnim energetskim pretvaračima (SMPCs). Nakon kratkog pregleda praktičnih iskustava iz literature, predstavljene su prednosti nekoliko slučajnih shema za energetske pretvarače (smanjena elektromagnetska interferencija - EMI, i niži akustični šum). Također, uvedena je matematička podloga za rad sa slučajnom modulacijom u području srednjih frekvencija: spektralna gustoća snage (PSD). Konačno, EMI mjerenja potvrđuju poboljšanja EMC performansi slučajnih uzlaznih ispravljača, kao i DC-DC silaznih pretvarača
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