We study the phase diagram and critical behavior of the two-dimensional square-lattice fully frustrated XY model (FFXY) and of two related models, a lattice discretization of the Landau-Ginzburg-Wilson Hamiltonian for the critical modes of the FFXY model, and a coupled Ising-XY model. We present a finite-size-scaling analysis of the results of high-precision Monte Carlo simulations on square la...

The quantum XY model shows a Berezinskii-Kosterlitz-Thouless (BKT) transition between a phase with quasi long-range order and a disordered one, like the corresponding classical model. The effect of the quantum fluctuations is to weaken the transition and eventually to destroy it. However, in this respect the mechanism of disappearance of the transition is not yet clear. In this work we address ...

We study the combinatorial complexity of Voronoi diagram of point sites on a general triangulated 2-manifold surface, based on the geodesic metric. Given a triangulated 2-manifold T of n faces and a set of m point sites S = {s1, s2, · · · , sm} ∈ T , we prove that the complexity of Voronoi diagram VT (S) of S on T is O(mn) if the genus of T is zero. For a genus-g manifold T in which the samples...

We present an angiofibroma of soft tissue with the karyotype 46,XY,t(4;5)(q24;q31),t(5;8;17)(p15;q13;q21)[8]/46,XY,t(1;14)(p31;q32)[2]/46,XY[3]. RNA‑sequencing showed that the t(4;5)(q24;q31) resulted in recombination of the genes TBCK on 4q24 and P4HA2 on 5q31.1 with generation of an in‑frame TBCK‑P4HA2 and the reciprocal but out‑of‑frame P4HA2‑TBCK fusion transcripts. The putative TBCK‑P4HA2 ...

One hundred and sixty six children attending educationally subnormal/mild (ESN/M) schools were karyotyped as part of a project investigating the aetiology of mild mental retardation. Nine had significant chromosome abnormalities. Five of six children identified during the survey had no dysmorphic features--47,XXY (two), 48,XXYY, 46,XX 15q-, and 46,XX,t(X;19). One dysmorphic boy had a balanced t...

We study the phase diagram of the two-dimensional fully frustrated XY model (FFXY) and of two related models, a lattice discretization of the Landau-Ginzburg-Wilson Hamiltonian for the critical modes of the FFXY model, and a coupled Ising-XY model. We present Monte Carlo simulations on square lattices L × L, L . 10. We show that the lowtemperature phase of these models is controlled by the same...

We consider the anisotropic quantum Heisenberg antiferromagnet (with anisotropy λ) on a square lattice using a Chern-Simons (or Wigner-Jordan) approach. We show that the Average Field Approximation (AFA) yields a phase diagram with two phases: a Neèl state for λ > λc and a flux phase for λ < λc separated by a second order transition at λc < 1. We show that this phase diagram does not describe t...

s of all papers presented at the meeting are given below. Papers read by title are indicated by the letter t" Paper number 48 was presented by Professor Chatland, number 54 by Mr. Block, number 58 by Professor Ulrich, number 72 by Mr. Kelly, and number 82 by Dr. Moise. ALGEBRA AND THEORY OF NUMBERS 47/. A. A. Albert: Power-associative rings. I I . A power-associative algebra A over a field F is...

We carry out simulations of the anisotropic uniformly frustrated three-dimensional XY model, as a model for vortex line fluctuations in high-Tc superconductors. We compute the phase diagram as a function of temperature and anisotropy, for a fixed applied magnetic field B . We find that superconducting coherence parallel to B persists into the vortex line liquid state, vanishing at a Tcz above t...