Quantum Hall transitions: An exact theory based on conformal restriction

We revisit the problem of the plateau transition in the integer quantum Hall effect. Here we develop an analytical approach for this transition, based on the theory of conformal restriction. This is a mathematical theory that was recently developed within the context of the Schramm-Loewner evolution which describes the stochastic geometry of fractal curves and other stochastic geometrical fractal objects in 2D space. Observables elucidating the connection with the plateau transition include the so-called point-contact conductances (PCCs) between points on the boundary of the sample, described within the language of the Chalker-Coddington network model. We show that the disorder-averaged PCCs are characterized by classical probabilities for certain geometric objects in the plane (pictures), occurring with positive statistical weights, that satisfy the crucial restriction property with respect to changes in the shape of the sample with absorbing boundaries. Upon combining this restriction property with the expected conformal invariance at the transition point, we employ the mathematical theory of conformal restriction measures to relate the disorder-averaged PCCs to correlation functions of primary operators in a conformal field theory (of central charge $c=0$). We show how this can be used to calculate these functions in a number of geometries with various boundary conditions. Since our results employ only the conformal restriction property, they are equally applicable to a number of other critical disordered electronic systems in 2D. For most of these systems, we also predict exact values of critical exponents related to the spatial behavior of various disorder-averaged PCCs.Comment: Published versio

Adaptation of Autocatalytic Fluctuations to Diffusive Noise

Evolution of a system of diffusing and proliferating mortal reactants is analyzed in the presence of randomly moving catalysts. While the continuum description of the problem predicts reactant extinction as the average growth rate becomes negative, growth rate fluctuations induced by the discrete nature of the agents are shown to allow for an active phase, where reactants proliferate as their spatial configuration adapts to the fluctuations of the catalysts density. The model is explored by employing field theoretical techniques, numerical simulations and strong coupling analysis. For d<=2, the system is shown to exhibits an active phase at any growth rate, while for d>2 a kinetic phase transition is predicted. The applicability of this model as a prototype for a host of phenomena which exhibit self organization is discussed.Comment: 6 pages 6 figur

Generic critical points of normal matrix ensembles

The evolution of the degenerate complex curve associated with the ensemble at a generic critical point is related to the finite time singularities of Laplacian Growth. It is shown that the scaling behavior at a critical point of singular geometry $x^3 \sim y^2$ is described by the first Painlev\'e transcendent. The regularization of the curve resulting from discretization is discussed.Comment: Based on a talk given at the conference on Random Matrices, Random Processes and Integrable Systems, CRM Montreal, June 200

Molecular Characterization of a 21.4 Kilobase Antibiotic Resistance Plasmid from an α-Hemolytic Escherichia coli O108:H- Human Clinical Isolate

This study characterizes the 21.4 kilobase plasmid pECTm80 isolated from Escherichia coli strain 80, an α hemolytic human clinical diarrhoeal isolate (serotype O108:H-). DNA sequence analysis of pECTm80 revealed it belonged to incompatibility group X1, and contained plasmid partition and toxin-antitoxin systems, an R6K-like triple origin (ori) replication system, genes required for replication regulation, insertion sequences IS1R, ISEc37 and a truncated transposase gene (Tn3-like ΔtnpA) of the Tn3 family, and carried a class 2 integron. The class 2 integron of pECTm80 contains an intact cassette array dfrA1-sat2, encoding resistance to trimethoprim and streptothricin, and an aadA1 gene cassette truncated by the insertion of IS1R. The complex plasmid replication system includes α, β and γ origins of replication. Pairwise BLASTn comparison of pECTm80 with plasmid pE001 reveals a conserved plasmid backbone suggestive of a common ancestral lineage. Plasmid pECTm80 is of potential clinical importance, as it carries multiple genes to ensure its stable maintenance through successive bacterial cell divisions and multiple antibiotic resistance genes

The self in prejudice

Abstract: The self as a psychological construct, and the self in relation to the other has been discussed in psychological and sociological literature for decades, but not much attention has been given to the psychological development of the self in relation to the social construction of prejudice. The primary aim of this article is to explore the self in prejudice and thus the psychological processes involved in the development of self within the social context. Consequently, the aim is to explore the self in the construction and expression of prejudice from both a social and psychological approach, and to explain selfhood influences at the individual, group and community levels. I use the conceptual framework of Kohut’s self psychology as a lens to present the development of the self and thus the idea of the development of the self in relation to the other. In such exploration of self in prejudice, I present some of my ideas which include prejudice as an outcome of self-definition in the context of the other, as well as linking self in prejudice and group dynamics to attachment theory and the notion of “selfgroup’ in terms of overidentification with the in-group. While the social and the psychological in terms of the development of the self cannot be separated, I have therefore attempted to merge at some point the two bodies of thought in relation to the self in prejudice

Review Essay : Industrial Organization and Socialist Development in China

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68697/2/10.1177_009770047900500204.pd

Distinguishing blood and lymph vessel invasion in breast cancer: a prospective immunohistochemical study

Recently, peritumoural (lympho)vascular invasion, assessed on haematoxylin–eosin (HE)-stained slides, was added to the St Gallen criteria for adjuvant treatment of patients with operable breast cancer (BC). New lymphatic endothelium-specific markers, such as D2-40, make it possible to distinguish between blood (BVI) and lymph vessel invasion (LVI). The aim of this prospective study was to quantify and compare BVI and LVI in a consecutive series of patients with BC. Three consecutive sections of all formalin-fixed paraffin-embedded tissue blocks of 95 BC resection specimens were (immuno)histochemically stained in a fixed order: HE, anti-CD34 (pan-endothelium) and anti-D2-40 (lymphatic endothelium) antibodies. All vessels with vascular invasion were marked and relocated on the corresponding slides. Vascular invasion was assigned LVI (CD34⊕ or ⊖/D2-40⊕) or BVI (CD34⊕/D2-40⊖) and intra- (contact with tumour cells or desmoplastic stroma) or peritumoural. The number of vessels with LVI and BVI as well as the number of tumour cells per embolus were counted. Results were correlated with clinico-pathological variables. Sixty-six (69.5%) and 36 (37.9%) patients had, respectively, LVI and BVI. The presence of ‘vascular' invasion was missed on HE in 20% (peritumourally) and 65% (intratumourally) of cases. Although LVI and BVI were associated intratumourally (P=0.02), only peritumoural LVI, and not BVI, was associated with the presence of lymph node (LN) metastases (pperi=0.002). In multivariate analysis, peritumoural LVI was the only independent determinant of LN metastases. Furthermore, the number of vessels with LVI was larger than the number of vessels with BVI (P=0.001) and lymphatic emboli were larger than blood vessel emboli (P=0.004). We demonstrate that it is possible to distinguish between BVI and LVI in BC specimens using specific lymphatic endothelium markers. This is important to study the contribution of both processes to BC metastasis. Furthermore, immunohistochemical detection of lymphovascular invasion might be of value in clinical practice

Gut Microbiota Is a Key Modulator of Insulin Resistance in TLR 2 Knockout Mice

A genetic and pharmacological approach reveals novel insights into how changes in gut microbiota can subvert genetically predetermined phenotypes from lean to obese