Electron Mass Operator in a Strong Magnetic Field and Dynamical Chiral Symmetry Breaking

The electron mass operator in a strong magnetic field is calculated. The contribution of higher Landau levels of virtual electrons, along with the ground Landau level, is shown to be essential in the leading log approximation. The effect of the electron dynamical mass generation by a magnetic field is investigated. In a model with N charged fermions, it is shown that some critical number N_{cr} exists for any value of the electromagnetic coupling constant alpha, such that the fermion dynamical mass is generated with a doublet splitting for N < N_{cr}, and the dynamical mass does not arise at all for N > N_{cr}, thus leaving the chiral symmetry unbroken.Comment: 4 pages, REVTEX4, 3 figure

Errors and complications in hip arthroplasty using cement technology.

According to the latest qualitative European registers cement type of fixation of one or both components of the hip joint is used in 4,5-58 % of cases, and in Scandinavian countries the figure is close to 90%. Performing any kind of surgery on musculoskeletal system surgeon should be prepared for post-operative com­plications. This study presents analysis of errors and complications of 65 hip replacements using cement technology. The technical errors of hip replacement with cement technologies usage are: the uneven distribution of the cement mantle around the endoprosthesis components, incomplete filling of the femoral medullary canal and bed of acetabular bone with cement, incorrect position of the implant components in the bone bed. The nature and number of somatic complications after total cemented replacement, observed in the group of patients that we investigated were: a transient drop in blood pressure − 11 (78.6 %) cases, thrombophlebitis − 1 (7.1%) case, transient coronary arteries ischemia − 1 (7.1%) case, cerebrovascular complications − 1 (7.1%) case

Analysis of patterns formed by two-component diffusion limited aggregation

We consider diffusion limited aggregation of particles of two different kinds. It is assumed that a particle of one kind may adhere only to another particle of the same kind. The particles aggregate on a linear substrate which consists of periodically or randomly placed particles of different kinds. We analyze the influence of initial patterns on the structure of growing clusters. It is shown that at small distances from the substrate, the cluster structures repeat initial patterns. However, starting from a critical distance the initial periodicity is abruptly lost, and the particle distribution tends to a random one. An approach describing the evolution of the number of branches is proposed. Our calculations show that the initial patter can be detected only at the distance which is not larger than approximately one and a half of the characteristic pattern size.Comment: Accepted for publication in Physical Review

Electron mass operator in a strong magnetic field

The electron mass operator in a strong magnetic field is calculated by summation of the leading log contributions in all orders of the perturbation theory. An influence of the strong field on the virtual photon polarization operator is taken into account. The contribution of higher Landau levels of virtual electrons, along with the ground Landau level, is shown to be essential in the leading log approximation.Comment: 7 pages, LATEX, 1 PS figure, submitted to Modern Physics Letters

Intermittency as a universal characteristic of the complete chromosome DNA sequences of eukaryotes: From protozoa to human genomes

Large-scale dynamical properties of complete chromosome DNA sequences of eukaryotes are considered. By the proposed deterministic models with intermittency and symbolic dynamics we describe a wide spectrum of large-scale patterns inherent in these sequences, such as segmental duplications, tandem repeats, and other complex sequence structures. It is shown that the recently discovered gene number balance on the strands is not of random nature, and a complete chromosome DNA sequence exhibits the properties of deterministic chaos.Comment: 4 pages, 5 figure

The impact of obesity on the structure of osteoarthrosis of large joints of the lower limb.

The prevalence of osteoarthrosis (OA) among adults over 40 years is taking one of the leading places in the common structure of joint pathology. Obesity – is of the comorbidities associated with OA, one of the risk factors of development and progression of OA. The aim of this study was to evaluate the influence of obesity on the structure of knee and hip OA on the stage of total joint replacement, depending on the patient`s gender, age and degree of obesity. The study involved 170 inpatient case histories of patients with OA undergoing treatment in the department of  large joints replacement (64 men and 106 women): 95 patients with OA of hip joint and 75 – with OA of knee joint, among whom there were 110 patients with obesity and 60 – without it. The middle age of the patients was by 63,8±7,69 years. High prevalence of obesity among patients with OA of knee and hip joints was found, with significant higher number of obese patients with OA of knee joint and among female patients. It has been demonstrated a significant increase in the frequency of total knee joint replacement associated with the increase of body mass index among patients with OA of knee joint. The presence of obesity was associated with earlier terms of the total joint replacement performing, especially among male patients

Classical motion in force fields with short range correlations

We study the long time motion of fast particles moving through time-dependent random force fields with correlations that decay rapidly in space, but not necessarily in time. The time dependence of the averaged kinetic energy and mean-squared displacement is shown to exhibit a large degree of universality; it depends only on whether the force is, or is not, a gradient vector field. When it is, p^{2}(t) ~ t^{2/5} independently of the details of the potential and of the space dimension. Motion is then superballistic in one dimension, with q^{2}(t) ~ t^{12/5}, and ballistic in higher dimensions, with q^{2}(t) ~ t^{2}. These predictions are supported by numerical results in one and two dimensions. For force fields not obtained from a potential field, the power laws are different: p^{2}(t) ~ t^{2/3} and q^{2}(t) ~ t^{8/3} in all dimensions d\geq 1

Polarization change due to fast winds from accretion disks

A fraction of the radiation produced by an accretion disk may be Thomson scattered by a wind flowing away from the disk. Employing a simple plane-parallel model of the wind, we calculate the polarization of the scattered radiation and find that its sign depends on the wind velocity, beta=v/c. In the case, 0.12 < beta < 0.78, the polarization is parallel to the disk normal, i.e., it is orthogonal to the standard Chandrasekhar's polarization expected from accretion disks. The velocity of an electron-positron wind is likely to saturate near the equilibrium value beta_* of order 0.5 for which the accelerating radiation pressure is balanced by the Compton drag. Then the change of polarization by the wind is most pronounced. This may help to reconcile the standard accretion disk model with the optical polarimetric observations of non-blazar AGNs.Comment: accepted for publication in ApJ Letter