Theory of the Spatio-Temporal Dynamics of Transport Bifurcations

The development and time evolution of a transport barrier in a magnetically confined plasma with non-monotonic, nonlinear dependence of the anomalous flux on mean gradients is analyzed. Upon consideration of both the spatial inhomogeneity and the gradient nonlinearity of the transport coefficient, we find that the transition develops as a bifurcation front with radially propagating discontinuity in local gradient. The spatial location of the transport barrier as a function of input flux is calculated. The analysis indicates that for powers slightly above threshold, the barrier location $x_b(t) \sim ( D_n t (P-P_c)/P_c)^{1/2},$ where $P_c$ is the local transition power threshold and $D_n$ is the neoclassical diffusivity . This result suggests a simple explanation of the high disruptivity observed in reversed shear plasmas. The basic conclusions of this theory are insensitive to the details of the local transport model.Comment: 21 page Tex file, 10 postscript file

Sino-Soviet Relations Since the Death of Mao Zedong

Territorial and ideological disputes are not new phenomena in the relations of China and the U.S.S.R. nor of China and Russia. Cultural differences and personality conflicts also have made their negative contribution. Now new economic and political realities are bound to aggravate the disputes and differences

A Story of Privileges and Immunities: From Medieval Concept to the Colonies and United States Constitution

Commentators often advocate that the privileges and immunities language found in the United States Constitution represents authority for some right along the spectrum of natural law, the Bill of Rights, or fundamental law in general. This Article provides contextual background for the argument by examining medieval royal privileges and immunities and tracing the crown’s charter to the American colonies and the United States Constitution. This Article goes beyond merely providing a short background for the use of the language in revolutionary pamphlets and the U.S. Constitution; rather, this Article discusses the concept of royal privileges and immunities and traces its growth in England and influence on the colonies. Along the way, useful comparisons are made between English institutions and American institutions

Personality disorder in primary care : factors associated with therapy process and outcome.

Assessment and treatment of personality disorder (PD) is a key issue in UK mental health service provision (NIMH report, 2003), but there is limited information on individuals with personality disorder presenting to primary care mental health services. This study investigates the characteristics of PD in individuals receiving cognitive behaviour therapy (CBT) following GP referral and its relationship with therapist ratings of treatment process and outcome. One hundred and forty-eight participants completed the Millon Multiaxial Clinical Inventory (MCMI-III: Millon, Davis and Millon, 1997). Therapists completed a measure of therapy process and outcome (TPOQ) on 100 participants. Key therapy and process questions were answered for 60 participants who attended a minimum of five therapy sessions. MCMI-III indicated a rate of PD of 56.4%. Factor analysis of PD scales identified two factors: inward looking/emotionally distanced, and aggressive/acting out. For clinical syndromes (CLS), the factors were general psychopathology and substance abuse. TPOQ had two factors: therapeutic alliance and complexity in therapy. Regression analyses indicated that only those PDs contributing to the inward looking/emotionally distanced scale score were associated with therapeutic alliance problems. Conversely, complexity in therapy was only predicted by general psychopathology and not by personality disorder. This study identified high rates of personality disorder in primary care referrals to a clinical psychology service. It also indicated that relationships between the presence of personality disorder and therapist ratings of treatment difficulties were only associated with certain types of personality disorder. These findings are discussed in relation to service and therapy planning in mental health

Bioluminescence Imaging to Detect Late Stage Infection of African Trypanosomiasis.

Human African trypanosomiasis (HAT) is a multi-stage disease that manifests in two stages; an early blood stage and a late stage when the parasite invades the central nervous system (CNS). In vivo study of the late stage has been limited as traditional methodologies require the removal of the brain to determine the presence of the parasites. Bioluminescence imaging is a non-invasive, highly sensitive form of optical imaging that enables the visualization of a luciferase-transfected pathogen in real-time. By using a transfected trypanosome strain that has the ability to produce late stage disease in mice we are able to study the kinetics of a CNS infection in a single animal throughout the course of infection, as well as observe the movement and dissemination of a systemic infection. Here we describe a robust protocol to study CNS infections using a bioluminescence model of African trypanosomiasis, providing real time non-invasive observations which can be further analyzed with optional downstream approaches

Scalable simultaneous multi-qubit readout with 99.99% single-shot fidelity

We describe single-shot readout of a trapped-ion multi-qubit register using space and time-resolved camera detection. For a single qubit we measure 0.9(3)x10^{-4} readout error in 400us exposure time, limited by the qubit's decay lifetime. For a four-qubit register (a "qunybble") we measure an additional error of only 0.1(1)x10^{-4} per qubit, despite the presence of 4% optical cross-talk between neighbouring qubits. A study of the cross-talk indicates that the method would scale with negligible loss of fidelity to ~10000 qubits at a density <~1 qubit/um^2, with a readout time ~1us/qubit.Comment: 4 pages, 3 figures; simulations added to fig.3, with some further text and figure revisions. Main results unchanged

Effects of ExB Velocity Shear and Magnetic Shear on Turbulence and Transport in Magnetic Confinement Devices

One of the scientific success stories of fusion research over the past decade is the development of the ExB shear stabilization model to explain the formation of transport barriers in magnetic confinement devices. This model was originally developed to explain the transport barrier formed at the plasma edge in tokamaks after the L (low) to H (high) transition. This concept has the universality needed to explain the edge transport barriers seen in limiter and divertor tokamaks, stellarators, and mirror machines. More recently, this model has been applied to explain the further confinement improvement from H (high)-mode to VH (very high)-mode seen in some tokamaks, where the edge transport barrier becomes wider. Most recently, this paradigm has been applied to the core transport barriers formed in plasmas with negative or low magnetic shear in the plasma core. These examples of confinement improvement are of considerable physical interest; it is not often that a system self-organizes to a higher energy state with reduced turbulence and transport when an additional source of free energy is applied to it. The transport decrease that is associated with ExB velocity shear effects also has significant practical consequences for fusion research. The fundamental physics involved in transport reduction is the effect of ExB shear on the growth, radial extent and phase correlation of turbulent eddies in the plasma. The same fundamental transport reduction process can be operational in various portions of the plasma because there are a number ways to change the radial electric field Er. An important theme in this area is the synergistic effect of ExB velocity shear and magnetic shear. Although the ExB velocity shear appears to have an effect on broader classes of microturbulence, magnetic shear can mitigate some potentially harmful effects of ExB velocity shear and facilitate turbulence stabilization