Path Integral Bosonization of Massive GNO Fermions

We show the quantum equivalence between certain symmetric space sine-Gordon models and the massive free fermions. In the massless limit, these fermions reduce to the free fermions introduced by Goddard, Nahm and Olive (GNO) in association with symmetric spaces $K/G$. A path integral formulation is given in terms of the Wess-Zumino-Witten action where the field variable $g$ takes value in the orthogonal, unitary, and symplectic representations of the group $G$ in the basis of the symmetric space. We show that, for example, such a path integral bosonization is possible when the symmetric spaces $K/G$ are $SU(N) \times SU(N)/SU(N); N \le 3, ~ Sp(2)/U(2)$ or $SO(8)/U(4)$. We also address the relation between massive GNO fermions and the nonabelian solitons, and explain the restriction imposed on the fermion mass matrix due to the integrability of the bosonic model.Comment: 11 page

Explicit Relation of Quantum Hall Effect and Calogero-Sutherland Model

Explicit relation between Laughlin state of the quantum Hall effect and one-dimensional(1D) model with long-ranged interaction ($1/r^2$) is discussed. By rewriting lowest Landau level wave functions in terms of 1D representation, Laughlin state can be written as a deformation of the ground state of Calogero-Sutherland model. Corresponding to Laughlin state on different geometries, different types of 1D $1/r^2$ interaction models are derived.Comment: 10 page

Geometric Classification of Conformal Anomalies in Arbitrary Dimensions

We give a complete geometric description of conformal anomalies in arbitrary, (necessarily even) dimension. They fall into two distinct classes: the first, based on Weyl invariants that vanish at integer dimensions, arises from finite -- and hence scale-free -- contributions to the effective gravitational action through a mechanism analogous to that of the (gauge field) chiral anomaly. Like the latter, it is unique and proportional to a topological term, the Euler density of the dimension, thereby preserving scale invariance. The contributions of the second class, requiring introduction of a scale through regularization, are correlated to all local conformal scalar polynomials involving powers of the Weyl tensor and its derivatives; their number increases rapidly with dimension. Explicit illustrations in dimensions 2, 4 and 6 are provided.Comment: Brandeis BRX--343, SISSA 14/93/E

Quantum fluctuations of the Chern-Simons theory and dynamical dimensional reduction

We consider a large-N Chern-Simons theory for the attractive bosonic matter (Jackiw-Pi model) in the Hamiltonian collective-field approach based on the 1/N expansion. We show that the dynamics of low-lying density excitations around the ground-state vortex configuration is equivalent to that of the Sutherland model. The relationship between the Chern-Simons coupling constant lambda and the Calogero-Sutherland statistical parameter lambda_s signalizes some sort of statistical transmutation accompanying the dimensional reduction of the initial problem.Comment: 10 pages, 2 figure

Asymptomatic internal carotid artery stenosis and cerebrovascular risk stratification

Background The purpose of this study was to determine the cerebrovascular risk stratification potential of baseline degree of stenosis, clinical features, and ultrasonic plaque characteristics in patients with asymptomatic internal carotid artery (ICA) stenosis. Methods This was a prospective, multicenter, cohort study of patients undergoing medical intervention for vascular disease. Hazard ratios for ICA stenosis, clinical features, and plaque texture features associated with ipsilateral cerebrovascular or retinal ischemic (CORI) events were calculated using proportional hazards models. Results A total of 1121 patients with 50% to 99% asymptomatic ICA stenosis in relation to the bulb (European Carotid Surgery Trial [ECST] method) were followed-up for 6 to 96 months (mean, 48). A total of 130 ipsilateral CORI events occurred. Severity of stenosis, age, systolic blood pressure, increased serum creatinine, smoking history of more than 10 pack-years, history of contralateral transient ischemic attacks (TIAs) or stroke, low grayscale median (GSM), increased plaque area, plaque types 1, 2, and 3, and the presence of discrete white areas (DWAs) without acoustic shadowing were associated with increased risk. Receiver operating characteristic (ROC) curves were constructed for predicted risk versus observed CORI events as a measure of model validity. The areas under the ROC curves for a model of stenosis alone, a model of stenosis combined with clinical features and a model of stenosis combined with clinical, and plaque features were 0.59 (95% confidence interval [CI] 0.54-0.64), 0.66 (0.62-0.72), and 0.82 (0.78-0.86), respectively. In the last model, stenosis, history of contralateral TIAs or stroke, GSM, plaque area, and DWAs were independent predictors of ipsilateral CORI events. Combinations of these could stratify patients into different levels of risk for ipsilateral CORI and stroke, with predicted risk close to observed risk. Of the 923 patients with <70% stenosis, the predicted cumulative 5-year stroke rate was <5% in 495, 5% to 9.9% in 202, 10% to 19.9% in 142, and <20% in 84 patients. Conclusion Cerebrovascular risk stratification is possible using a combination of clinical and ultrasonic plaque features. These findings need to be validated in additional prospective studies of patients receiving optimal medical intervention alone. Copyright © 2010 by the Society for Vascular Surgery

The size of juxtaluminal hypoechoic area in ultrasound images of asymptomatic carotid plaques predicts the occurrence of stroke

Objective: To test the hypothesis that the size of a juxtaluminal black (hypoechoic) area (JBA) in ultrasound images of asymptomatic carotid artery plaques predicts future ipsilateral ischemic stroke. Methods: A JBA was defined as an area of pixels with a grayscale value &lt;25 adjacent to the lumen without a visible echogenic cap after image normalization. The size of a JBA was measured in the carotid plaque images of 1121 patients with asymptomatic carotid stenosis 50% to 99% in relation to the bulb (Asymptomatic Carotid Stenosis and Risk of Stroke study); the patients were followed for up to 8 years. Results: The JBA had a linear association with future stroke rate. The area under the receiver-operating characteristic curve was 0.816. Using Kaplan-Meier curves, the mean annual stroke rate was 0.4% in 706 patients with a JBA &lt;4 mm 2, 1.4% in 171 patients with a JBA 4 to 8 mm2, 3.2% in 46 patients with a JBA 8 to 10 mm2, and 5% in 198 patients with a JBA &gt;10 mm2 (P &lt;.001). In a Cox model with ipsilateral ischemic events (amaurosis fugax, transient ischemic attack [TIA], or stroke) as the dependent variable, the JBA (&lt;4 mm2, 4-8 mm2, &gt;8 mm2) was still significant after adjusting for other plaque features known to be associated with increased risk, including stenosis, grayscale median, presence of discrete white areas without acoustic shadowing indicating neovascularization, plaque area, and history of contralateral TIA or stroke. Plaque area and grayscale median were not significant. Using the significant variables (stenosis, discrete white areas without acoustic shadowing, JBA, and history of contralateral TIA or stroke), this model predicted the annual risk of stroke for each patient (range, 0.1%-10.0%). The average annual stroke risk was &lt;1% in 734 patients, 1% to 1.9% in 94 patients, 2% to 3.9% in 134 patients, 4% to 5.9% in 125 patients, and 6% to 10% in 34 patients. Conclusions: The size of a JBA is linearly related to the risk of stroke and can be used in risk stratification models. These findings need to be confirmed in future prospective studies or in the medical arm of randomized controlled studies in the presence of optimal medical therapy. In the meantime, the JBA may be used to select asymptomatic patients at high stroke risk for carotid endarterectomy and spare patients at low risk from an unnecessary operation

Principais fatores prognósticos e modalidades fisioterapêuticas associados à recuperação funcional em pacientes com paralisia facial periférica

Patients with peripheral facial paralysis (PFP) have some degree of recovery. The aim of this study was to evaluate prognostic factors and physical therapy modalities associated with functional recovery in patients with PFP. This is a cohort study with 33 patients. We collected the following variables of patients who underwent treatment at the rehabilitation center: age, sex, risk factors, affected side, degree of facial paralysis (House-Brackmann scale), start of rehabilitation, and therapy modality (kinesiotherapy only; kinesiotherapy with excitomotor electrotherapy; and kinesiotherapy with excitomotor electrotherapy and photobiomodulation therapy). The outcomes were: degree of facial movement (House-Brackmann) and face scale applied 90 days after treatment. Degree of PFP was associated with functional recovery (RR=0.51, 95% CI: 0.51-0.98; p=0.036). The facial movement was associated with the time to start rehabilitation (r=−0.37; p=0.033). Lower facial comfort was observed among women, worse ocular comfort was associated with diabetes mellitus, worse tear control with prior PFP, and worse social function with the degree of PFP. Our results indicate that the all modalities present in this study showed the same result in PFP. Recovery of PFP was associated with degree of nerve dysfunction, the length of time to onset of rehabilitation, femLos pacientes con parálisis facial periférica (PFP) tienen diferentes grados de recuperación. El presente estudio tuvo como objetivo evaluar los factores pronósticos y las modalidades de fisioterapia relacionadas a la recuperación funcional de pacientes con PFP. Este es un estudio de cohorte prospectivo con 33 pacientes. Se recogieron las siguientes variables de pacientes sometidos a tratamiento en el centro de rehabilitación: edad, sexo, factores de riesgo, lado afectado, grado de parálisis facial (escala de House-Brackmann), inicio de la rehabilitación y modalidad de terapia (kinesioterapia, kinesioterapia asociada a la electroterapia, kinesioterapia asociada a la electroterapia y terapia de fotobiomodulación). Los resultados fueron: grado de movimiento facial (House-Brackmann) y face scale, aplicados 90 días después del tratamiento. El grado de PFP se asoció con la recuperación funcional (RR=0,51,95% IC: 0,51-0,98; p=0,036). El movimiento facial se asoció con el tiempo para comenzar la rehabilitación (r=−0,37; p=0,033). Se observó menor comodidad facial entre las mujeres, peor comodidad ocular en personas con diabetes mellitus, peor control lagrimal en individuos con PFP previa y peor función social con el grado de PFP. Todas las modalidades presentadas en este estudio tuvieron el mismo resultado en PFP. La recuperación de la PFP se asoció con el grado de disfunción nerviosa, el tiempo inicial de la rehabilitación, el sexo femenino, la hipertensión arterial sistémica, la diabetes mellitus y la PFP previa, todos asociados con peores resultados en face scale.Os pacientes com paralisia facial periférica (PFP) apresentam diversos graus de recuperação. O objetivo deste estudo foi avaliar os fatores prognósticos e as modalidades fisioterapêuticas associados à recuperação funcional em pacientes com PFP. Trata-se de um estudo coorte prospectiva de 33 pacientes. Foram coletadas variáveis de pacientes submetidos ao tratamento no centro de reabilitação: idade, sexo, fatores de risco, lado afetado, grau de paralisia facial (escala de House-Brackmann), início da reabilitação e modalidade de terapia (cinesioterapia; cinesioterapia associada à eletroterapia; cinesioterapia associada à eletroterapia e terapia de fotobiomodulação). Os desfechos foram: grau de movimento facial (House-Brackmann) e face scale aplicados 90 dias após o tratamento. O grau de PFP foi associado à recuperação funcional (RR=0,51, 95% IC: 0,51-0,98; p=0,036). O movimento facial foi associado com o tempo para iniciar a reabilitação (r=−0,37; p=0,033). Menor conforto facial foi observado entre as mulheres, pior conforto ocular em indivíduos com diabetes mellitus, pior controle lacrimal em indivíduos com PFP prévia e pior função social com o grau de PFP. Todas as modalidades apresentadas neste estudo tiveram o mesmo resultado na PFP. A recuperação da PFP foi associada ao grau de disfunção nervosa, ao tempo de início da reabilitação, ao sexo feminino, à hipertensão arterial sistêmica, ao diabetes mellitus e à PFP prévia, todos associados a piores desfechos na face scale