Integrated Study of the Nonlinear Dynamics of Collisional Drift Wave Turbulence

An existing linear magnetized plasma device, the Controlled Shear Decorrelation experiment (CSDX) was used to study the transition from a state of coherent wave like activity to a state of turbulent activity using the magnetic field and thus magnetization of the plasma as the control parameter. The results show the onset of coherent drift waves consistent with linear stability analysis. As the magnetization is raised, at first multiple harmonics appear, consistent with wave steepening. This period is then followed by the beginning of nonlinear interactions between different wave modes, which then results in the formation of narrow frequency but distributed azimuthal wave number fluctuations that are consistent with the formation of long-lived coherent nonlinear structures within the plasmas. These structures, termed quasicoherent modes, persist as the magnetic field is raised. Measurements of turbulent momentum flux indicate that the plasma is also forming an azimuthally symmetric radially sheared fluid flow that is nonlinearly driven by smaller scaled turbulent fluctuations. Further increases in the magnetic field result in the breakup of the quasicoherent mode, and the clear formation of the sheared flow. Numerical simulations of the experiment reproduce the formation of the sheared flow via a vortex merging process, and confirm that the experiment is providing the first clear experimental evidence of the formation of sheared zonal flows from drift turbulent fluctuations in a magnetized plasma

General Hospitals, Specialty Hospitals and Financially Vulnerable Patients

Examines whether specialty hospitals draw well-insured patients away from general and safety-net hospitals, reducing their ability to cross-subsidize less profitable services and uncompensated care, in three cities. Notes challenges and implications

Coordination of Care by Primary Care Practices: Strategies, Lessons and Implications

Documents successful strategies for coordinating care within primary care settings, including family and caregivers; with specialists; with hospital settings; and with community-based services. Discusses challenges, lessons learned, and implications

Edge Shear Flows and Particle Transport near the Density Limit in the HL-2A Tokamak

Edge shear flow and its effect on regulating turbulent transport have long been suspected to play an important role in plasmas operating near the Greenwald density limit $n_G$. In this study, equilibrium profiles as well as the turbulent particle flux and Reynolds stress across the separatrix in the HL-2A tokamak are examined as $n_G$ is approached in ohmic L-mode discharges. As the normalized line-averaged density $\bar{n}_e/n_G$ is raised, the shearing rate of the mean poloidal flow $\omega_{\rm sh}$ drops, and the turbulent drive for the low-frequency zonal flow (the Reynolds power $\mathcal{P}_{Re}$) collapses. Correspondingly, the turbulent particle transport increases drastically with increasing collision rates. The geodesic acoustic modes (GAMs) gain more energy from the ambient turbulence at higher densities, but have smaller shearing rate than low-frequency zonal flows. The increased density also introduces decreased adiabaticity which not only enhances the particle transport but is also related to a reduction in the eddy-tilting and the Reynolds power. Both effects may lead to the cooling of edge plasmas and therefore the onset of MHD instabilities that limit the plasma density

Ventricular perforation as a complication of percutaneous valve replacement

Aortic stenosis (AS) is the most commonly encountered valvular disease in developed countries. Once symptomatic, this disease carries a dismal prognosis. Patients unfit for surgical valve replacement may require transcatheter aortic valve implantations (TAVI). We present a complication of this novel approach where a prosthetic valve is delivered through the femoral artery by means of a Retroflex delivery system developed by Edwards Lifesciences

USING THE SCHOOL PLAYING FIELD TO MEET THE PRACTICAL REQUIREMENTS ASSOCIATED WITH ECOLOGY SUBSTANTIVE KNOWLEDGE IN CURRENT BIOLOGY EXAMINATION SPECIFICATIONS IN ENGLAND

Examination specifications in England for General Certificate of Secondary Education (GCSE) and General Certificate of Education Advanced Special/Advanced (GCE AS/A) Level examinations changed from 2015 onwards to reflect education reforms affecting curriculum design and assessment set out in the government white paper of 2010 [1]. This prevented coursework, practical examinations, and modular examinations from contributing to external qualifications for learners leaving school at sixteen and eighteen years old. Substantive and discipline knowledge were to be tested by written end of course examinations [1]. For science subjects, practical coursework and examinations were replaced by a list of required practical activities accredited by teachers that help learners answer questions about practical and investigation skills on their final examination. These are the same for all the examination boards serving English schools, and the Assessment and Qualifications Alliance (AQA) specifications for GCSE and GCE AS/A Level Biology [2] [3] can be used as typical examples. A previous International Academy of Technology, Education and Development (IATED) conference proceedings paper [4] discussed the use of a natural ecosystem on Merseyside in the northwest of England by pre-service science teachers to teach ecology. Using the school grounds is an alternative strategy that avoids some of the challenges associated with conducting fieldwork away from the school environment. School playing fields are a surprisingly diverse ecosystem with plants adapted to differing niches and distributed according to several abiotic environmental factors that can fluctuate over short distances e.g. soil pH, trampling, mowing, light exposure, nitrate depletion, etc. GCSE and GCE AS/A level required practical activities [2] [3] linked to the ecology sections of the specifications are discussed. Examples demonstrate how random and systematic sampling using quadrats on school fields can be effective in demonstrating the distributions of species, linking this to the measurement of abiotic factors. The practical requirement for GCE AS/A Level is very similar to GCSE and using a version of Association Analysis developed on Field Studies Council [5] field trips is discussed as a strategy for progression

A critical evaluation of criteria-based assessment of subject knowledge and other competencies of teachers in training

This thesis draws together a portfolio of nine peer reviewed papers investigating the assessment of teacher competencies. Earlier papers studied the effectiveness of a particular model for delivering a subject knowledge enhancement course in creating new physical science teachers from those without chemistry or physics first degrees. This programme was attended, year-long, full-time and higher education accredited. Later papers widened the scope to include the assessment of teacher subject knowledge and other competencies in a range of school subjects in the English education system. The portfolio adopted a mixed methods approach with an emphasis on quantitative analysis. In considering the body of research, a critical realism perspective was adopted to describe and interpret the findings in terms of many demonstrable phenomena concerned with assessment as an event. An underlying mechanism is proposed to explain these in terms of the assessment behaviours of teacher practitioners who also act as teacher educator practitioners and may experience role conflict: conflicted role, professional judgement. This approach locates the portfolio’s contribution to new knowledge against pre-existing work, makes clear unifying and coherent themes and establishes the papers’ individual and combined methodological rigour. The research has great local utility in initial teacher education in England. It also demonstrated issues with criteria-based assessment of teaching described through competencies and the problems with adopting number grades to aid quality assurance and accountability. Findings have relevance and may be applicable to all similar assessment systems in any profession

Searching for an underlying mechanism governing pre-service teacher assessment in the northwest of England: an example of adopting a critical realism approach for teacher education research

Bhaskar [1] proposed and argued for critical realism in natural sciences. Other authors have extended Bhaskar’s [1] arguments to include the social sciences [2], and to attempt to translate his philosophical position into useful research methodologies that can compete with positivist, constructivist, and pragmatic research paradigms [3]. Critical realism describes both intransitive and transitive components of human knowledge. It proposes underlying structures and mechanisms in the Real Domain that exist independently of human observers and possess the potential to govern events occurring in the Actual Domain [1]. Events that can be experienced and investigated as phenomena by human observers form a subset that occupies the Empirical Domain where researchers normally operate [1]. For critical realists, this positivist stance is balanced by the constructivist element to knowledge. As research is also a social activity, it results in knowledge regarding external structures and mechanisms that is also undeniably socially constructed [1] [2]. Critical realism [1] [2] claims to provide a philosophical and research paradigm solution to conflicts in ontology, epistemology, and axiology when conducting mixed methods studies [3]. Further, some researchers have advocated adopting a critical realism approach for synthesising the contributions of quantitative and qualitative data collected in such investigations, even in hindsight [4]. This paper considers the adoption of a critical realism approach late in a research project. A mini thesis drew together nine research articles in the field of teacher training and education that were published in peer reviewed journals between 2013 and 2019. These formed part of a PhD by published works submission [5]. The application of a critical realism approach as a triangulation of mixed methods data and findings using stages described by Bygstad and Munkvold [6] was found to be useful in formulating a concluding model for a complex project. However, a major criticism of the approach is also considered: that the same conclusions would have been reached following other research paradigm methodologies