Zero and finite temperature Casimir effect of massive vector field between real metals

We consider the Casimir effect of a massive vector field between two semi-infinite dielectric slabs. We first derive the generalization of the Lifshitz formula that gives the Casimir interaction energy of two magnetodielectric slabs separated by a magnetodielectric medium due to the vacuum fluctuations of a massive vector field. We then discuss the asymptotic behaviors of the Casimir energy and the Casimir force in various limits, such as low temperature, high temperature, small mass, large mass, up to the first order in the finite conductivity correction, for two real metal semispaces whose dielectric property is described by the plasma model. Application to the Casimir effect in Randall-Sundrum spacetime is briefly discussed.Comment: 19 page

When renormalizability is not sufficient: Coulomb problem for vector bosons

The Coulomb problem for vector bosons W incorporates a known difficulty; the boson falls on the center. In QED the fermion vacuum polarization produces a barrier at small distances which solves the problem. In a renormalizable SU(2) theory containing vector triplet (W^+,W^-,gamma) and a heavy fermion doublet F with mass M the W^- falls on F^+, to distances r ~ 1/M, where M can be made arbitrary large. To prevent the collapse the theory needs additional light fermions, which switch the ultraviolet behavior of the theory from the asymptotic freedom to the Landau pole. Similar situation can take place in the Standard Model. Thus, the renormalizability of a theory is not sufficient to guarantee a reasonable behavior at small distances for non-perturbative problems, such as a bound state problem.Comment: Four page

A Maximally Symmetric Vector Propagator

We derive the propagator for a massive vector field on a de Sitter background of arbitrary dimension. This propagator is de Sitter invariant and possesses the proper flat spacetime and massless limits. Moreover, the retarded Green's function inferred from it produces the correct classical response to a test source. Our result is expressed in a tensor basis which is convenient for performing quantum field theory computations using dimensional regularization.Comment: 21 pages, no figures, uses LaTeX 2 epsilon, version 2 has an error in eqn (86) corrected and an updated reference lis

Experimental test of magnetic photons

A "magnetic" photon hypothesis associated with magnetic monopoles is tested experimentally. These photons are predicted to easily penetrate metal. Experimentally the optical transmittance T of a metal foil was less than 2 x 10^-17. The hypothesis is not supported since it predicts T = 2 x 10^-12

Charge density of a positively charged vector boson may be negative

The charge density of vector particles, for example W, may change sign. The effect manifests itself even for a free propagation; when the energy of the W-boson is higher than sqrt{2}m and the standing-wave is considered the charge density oscillates in space. The charge density of W also changes sign in close vicinity of a Coulomb center. The dependence of this effect on the g-factor for an arbitrary vector boson, for example rho-meson, is discussed. An origin of this surprising effect is traced to the electric quadrupole moment and spin-orbit interaction of vector particles. Their contributions to the current have a polarization nature. The charge density of this current, rho = -\nabla \cdot P, where P is an effective polarization vector that depends on the quadrupole moment and spin-orbit interaction, oscillates in space, producing zero contribution to the total charge.Comment: 4 pages, revte

Внутрипеченочный холестаз беременных

Summary: intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disorder characterized by maternal pruritus in the third trimester, raised serum bile acids, and increased rates of adverse fetal outcomes. The etiology of ICP is complex and not fully understood, but it is likely to result from the cholestatic effects of reproductive hormones and their metabolites in genetically susceptible women. Equally unclear are the mechanisms by which the fetal complications occur. This article reviews the epidemiology, clinical features, diagnosis, etiology, and management of ICP.Резюме: Внутрипеченочный холестаз беременных называют также доброкачественным рецидивирующим холестазом беременности или зудом беременных. Этиология внутрипеченочного холестаза беременных неизвестна, заболевание проявляется обычно в третьем триместре беременности. Как правило, у матери заболевание протекает доброкачественно, однако при этом повышен риск преждевременных родов, мертворождения и развития патологических состояний плода. Холестаз рецидивирует при последующих беременностях и часто носит семейный характер. Применение урсодеоксихолевой кислоты в III-м триместре беременности не только облегчает зуд и улучшает состояние матери, не вызывая при этом побочных эффектов, но и существенно улучшает прогноз для плода. В данной статье обсуждаем патогенетические механизмы клинических проявлений и, отталкиваясь от них, рассматриваем возможные подходы к лечению

Reprezentări antropologice fictive ale specificului etnic în eseurile politice românești post-socialiste – două exemple

Istoria antropologiei culturale a înregistrat nu puţine descrieri mitologice sau interpretări ficţionale ale datelor etnografice, în așa măsură încât recursul la imaginaţie în caracterizarea „naturii umane” sau a diverselor grupuri sociale constituie un subiect de studiu în sine. El prezintă o cazuistică impresionantă când vine vorba de referirile la trăsăturile distinctive ale grupurilor etnice sau ale tradiţiilor naţionale, discursul politic despre acestea fiind încărcat de stereotipuri și reprezentări antropologice itologizate, care spun mai multe despre cei ce le vehiculează decât despre obiectul la care se referă. Studiul de faţă prezintă comparativ două exemple de manifestare a acestor reprezentări ficţionale cu implicaţii antropologice în discursul public românesc post-socialist

Coulomb problem for vector bosons versus Standard Model

The Coulomb problem for vector bosons W(+/-) propagating in an attractive Coulomb field incorporates a known difficulty, i.e. the total charge of the boson localized on the Coulomb center turns out infinite. This fact contradicts the renormalizability of the Standard model, which presumes that at small distances all physical quantities are well defined. The paradox is shown to be resolved by the QED vacuum polarization, which brings in a strong effective repulsion and eradicates the infinite charge of the boson on the Coulomb center. The effect makes the Coulomb problem for vector bosons well defined and consistent with the Standard Model.Comment: 4 page

Parent's knowledge about childhood obesity

George Emil Palade University of Medicine, Pharmacy, Science and Technology of Targu Mures, The 8th International Medical Congress for Students and Young Doctors, September 24-26, 2020Introduction. Childhood overweight or obesity has become a worldwide health problem due to its continuous increase of prevalence and its serious impact on health. In obesity, like in any other chronic pathology that appears in childhood, parents have an important role in monitoring the body weight and preventing future complications. Aim of the study. The aim of this study was to identify parent's knowledge about childhood obesity and their vision about the nutrition status of their children. Materials and methods. Our cross-sectional study was conducted over a period of six months ( july-november 2019). In this study participated parents with children aged 0-18 years, from Brasov and Mures counties, the sample size being 529 persons. The informations were acquired with the help of a self-administered questionnaire and the statistical analysis was performed using the Statistical Package for Social Sciences software. Results. After interpreting the data, it can be said that out of the 258 girls included in the study, 34 are obese and 30 are overweight. Regarding the male, out of the total of 271 persons, 49 are obese and 54 are overweight. The correlation between the parent's vision of the nutrition status of their children and the body mass index interpreted with the help of percentiles was statistically significant (p=0.0001). Parents who don't consider their children being obese, have, in fact, 19 obese children and 33 who are overweight. A number of 47 parents consider that they have obese children, but among them 85.1% are really obese and 14.9% are overweight. Conclusions. Firstly, it has been reported more cases of obesity and overweight among boys. Secondly, parents who have obese or overweight children, have a more objective appreciation of their nutritional status and are aware of the health problem their children are facing