Colour, copies and confinement

In this paper we construct a wide class of Gribov copies in Coulomb gauge SU(2) gauge theory. Infinitesimal copies are studied in some detail and their non-perturbative nature is made manifest. As an application it is shown that the copies prevent a non-perturbative definition of colour charge.Comment: 25 pages, 10 figures. Minor changes, two references added. Published versio

Laser-Derived, Particle Size Data from CRP-2/2A: Implications for Sequence and Seismic Stratigraphy

Gravel-free, high-resolution (1-metre spacing, 32 channel) particle size data from the CRP-2/2A drill core indicate that many of the diamictites were likely deposited from floating ice. Textural dislocations occur at most sequence boundaries and provide independent corroboration of the sequence stratigraphic interpretation. Likewise the data largely support the correlation drawn (Fielding et al., this volume) between the sequence stratigraphic cycles and the regional seismic stratigraphy (an alternative correlation to Reflector ‘f’ is also suggested). The gravel-free data appear to be reflecting predominantly regional (global?) forcing with some possible local effects, and long-term trends persisting through gravelly textural dislocations

Gauge invariance of dimension two condensate in Yang-Mills theory

Gauge independence of dimension two condensate in Yang-Mills theory is demonstrated by using a noncommutative theory technique.Comment: 7 page

The ice-limit of Coulomb gauge Yang-Mills theory

In this paper we describe gauge invariant multi-quark states generalising the path integral framework developed by Parrinello, Jona-Lasinio and Zwanziger to amend the Faddeev-Popov approach. This allows us to produce states such that, in a limit which we call the ice-limit, fermions are dressed with glue exclusively from the fundamental modular region associated with Coulomb gauge. The limit can be taken analytically without difficulties, avoiding the Gribov problem. This is llustrated by an unambiguous construction of gauge invariant mesonic states for which we simulate the static quark--antiquark potential.Comment: 25 pages, 4 figure

Intermediate Fidelity Closed Brayton Cycle Power Conversion Model

This paper describes the implementation of an intermediate fidelity model of a closed Brayton Cycle power conversion system (Closed Cycle System Simulation). The simulation is developed within the Numerical Propulsion Simulation System architecture using component elements from earlier models. Of particular interest, and power, is the ability of this new simulation system to initiate a more detailed analysis of compressor and turbine components automatically and to incorporate the overall results into the general system simulation

Student interprofessional mental health simulation (SIMHS): evaluating the impact on medical and nursing students, and clinical psychology trainees

Purpose: Mental health simulation is the educational practice of recreating clinical situations in safe environments using actors, followed by structured debriefing, to foster professional development and improve care. Although evidence outlines the benefits of simulation, few studies have examined the impact of interprofessional mental health simulation on healthcare trainees, which is more reflective of clinical care. The purpose of this paper is to evaluate the impact of mental health simulation training on students’ confidence, attitudes, knowledge and perceived professional development and anticipated clinical practice. Design/methodology/approach: Participants (n=56) were medical (41 per cent) and mental health nursing students (41 per cent), and clinical psychology trainees (18 per cent). Six simulated scenarios, involving one to three trainees, were followed by structured debriefs with trained facilitators. Scenarios, using actors, reflected patient journeys through emergency, medical and psychiatric settings. Participants’ confidence, knowledge and attitudes were measured quantitatively using pre- and post-course self-report questionnaires. Perceptions of impact on professional development and clinical practice were assessed using thematic analysis of post-course questionnaire responses. Findings: Knowledge, confidence and attitudes scores showed statistically significant increases, with large effect sizes. Thematic analyses highlighted themes of: interprofessionalism, communication skills, reflective practice, personal resilience, clinical skills and confidence. Research limitations/implications: Further research should clarify the impact of interprofessional simulation training on mental health practice in the context of other training received. Practical implications: Simulation training may begin to influence participants’ professional development and future clinical practice and subsequently care delivered, supporting its increased use in mental health. Originality/value: This study adds to nascent understandings of the use and potential of interprofessional mental health simulation, outlining innovative training, its positive outcomes and implications

Pretreatment health measures and complications after surgical management of elderly women with breast cancer

Elderly patients with breast cancer are less likely to be offered surgery, partly owing to co-morbidities and reduced functional ability. However, there is little consensus on how best to assess surgical risk in this patient group.The ability of pretreatment health measures to predict complications was investigated in a prospective cohort study of a consecutive series of women aged at least 70 years undergoing surgery for operable (stage I-IIIa) breast cancer at 22 English breast units between 2010 and 2013. Data on treatment, surgical complications, health measures and tumour characteristics were collected by case-note review and/or patient interview. Outcome measures were all complications and serious complications within 30 days of surgery.The study included 664 women. One or more complications were experienced by 41·0 per cent of the patients, predominantly seroma or primary/minor infections. Complications were serious in 6·5 per cent. More extensive surgery predicted a higher number of complications, but not serious complications. Older age did not predict complications. Several health measures were associated with complications in univariable analysis, and were included in multivariable analyses, adjusting for type/extent of surgery and tumour characteristics. In the final models, pain predicted a higher count of complications (incidence rate ratio 1·01, 95 per cent c.i. 1·00 to 1·01; P = 0·004). Fatigue (odds ratio (OR) 1·02, 95 per cent c.i. 1·01 to 1·03; P = 0·004), low platelet count (OR 4·19, 1·03 to 17·12: P = 0·046) and pulse rate (OR 0·96, 0·93 to 0·99; P = 0·010) predicted serious complications.The risk of serious complications from breast surgery is low for older patients. Surgical decisions should be based on patient fitness rather than age. Health measures that predict surgical risk were identified in multivariable models, but the effects were weak, with 95 per cent c.i. close to unity.This paper presents independent research funded by theBreast Cancer Campaign (2008NOVPR35), a NationalInstitute for Health Research (NIHR) Programme Grantfor Applied Research (RP-PG-0608-10168) and researcharising from a Post Doctoral Fellowship supported by theNIHR (PDF/01/2008/027). The views expressed in thispublication are those of the authors and not necessarilythose of the NHS, the NIHR or the Department of Health

Numerical Comparison of NASA's Dual Brayton Power Generation System Performance Using CO2 or N2 as the Working Fluid

A Dual Brayton Power Conversion System (DBPCS) has been tested at the NASA Glenn Research Center using Nitrogen (N2) as the working fluid. This system uses two closed Brayton cycle systems that share a common heat source and working fluid but are otherwise independent. This system has been modeled using the Numerical Propulsion System Simulation (NPSS) environment. This paper presents the results of a numerical study that investigated system performance changes resulting when the working fluid is changed from gaseous (N2) to gaseous carbon dioxide (CO2)

Using the NPSS Environment to Model an Altitude Test Facility

An altitude test facility was modeled using Numerical Propulsion System Simulation (NPSS). This altitude test facility model represents the most detailed facility model developed in the NPSS architecture. The current paper demonstrates the use of the NPSS system to define the required operating range of a component for the facility. A significant number of additional component models were easily developed to complete the model. Discussed in this paper are the additional components developed and what was done in the development of these components

Is the ground state of Yang-Mills theory Coulombic?

We study trial states modelling the heavy quark-antiquark ground state in SU(2) Yang-Mills theory. A state describing the flux tube between quarks as a thin string of glue is found to be a poor description of the continuum ground state; the infinitesimal thickness of the string leads to UV artifacts which suppress the overlap with the ground state. Contrastingly, a state which surrounds the quarks with non-abelian Coulomb fields is found to have a good overlap with the ground state for all charge separations. In fact, the overlap increases as the lattice regulator is removed. This opens up the possibility that the Coulomb state is the true ground state in the continuum limit.Comment: 10 pages, 9 .eps figure