Quark and pion condensation in a chromomagnetic background field

The general features of quark and pion condensation in dense quark matter with flavor asymmetry have been considered at finite temperature in the presence of a chromomagnetic background field modelling the gluon condensate. In particular, pion condensation in the case of a constant abelian chromomagnetic field and zero temperature has been studied both analytically and numerically. Under the influence of the chromomagnetic background field the effective potential of the system is found to have a global minimum for a finite pion condensate even for small values of the effective quark coupling constant. In the strong field limit, an effective dimensional reduction has been found to take place.Comment: 17 pages, 6 figure

The spatial variation of weathering and soil depth across a Triassic sandstone outcrop

In this study, we used an archive of borehole logs from the British Geological Survey to collect information on the spatial structure of weathering that extends from the surface to competent bedrock across the Triassic Sherwood Sandstone Group outcrop (750 km2), in the East Midlands, UK. The borehole logs were used to estimate the thickness of the soil (n = 280) and soil and saprolite (S&S) to competent rock (n = 500). The weathering profile of the sandstone consisted of soil (median thickness ∼ 1·5 m) overlying a transition zone of compacted and weakly cemented weathered sandstone saprolite over bedrock. Topographic analysis using a NEXTMAP 5 m × 5 m digital elevation model (DEM) revealed no significant relationships between slope properties (relief, flow length, flow accumulation or slope angle) and soil or S&S thickness. A weak, but statistically significant correlation was found between the thickness of the soil and S&S (rs = 0·25, p < 0·001, n = 192). The variation in soil thickness may be related to changes in current and historic and land-use, variation in sandstone properties and the influence of glacial/peri-glacial processes. The thickness of the saprolite was more variable towards the southern part of the study area, where it increased to a maximum 40 m. We hypothesize and provide evidence that the greater weathering thickness is related to the occurrence of increased faulting in this part of the study region, allowing increased access to meteoric waters. A possible source of increased water supply is meltwater from Quaternary ice sheets; the overburden of ice may have increased sub-glacial pore water pressure, with the fractures and faults acting as a drainage system for the removal of dissolved weathering product

A Higher Order Generative Framework for Weaving Traceability Links into a Code Generator for Web Application Testing

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Factors influencing the development of evidence-based practice: a research tool

Aim. The paper reports a study to develop and test a tool for assessing a range of factors influencing the development of evidence-based practice among clinical nurses. Background. Achieving evidence-based practice is a goal in nursing frequently cited by the profession and in government health policy directives. Assessing factors influencing the achievement of this goal, however, is complex. Consideration needs to be given to a range of factors, including different types of evidence used to inform practice, barriers to achieving evidence-based practice, and the skills required by nurses to implement evidence-based care. Methods. Measurement scales currently available to investigate the use of evidence in nursing practice focus on nurses’ sources of knowledge and on barriers to the use of research evidence. A new, wider ranging Developing Evidence-Based Practice questionnaire was developed and tested for its measurement properties in two studies. In study 1, a sample of 598 nurses working at two hospitals in one strategic health authority in northern England was surveyed. In study 2, a slightly expanded version of the questionnaire was employed in a survey of 689 community nurses in 12 primary care organizations in two strategic health authorities, one in northern England and the other in southern England. Findings. The measurement characteristics of the new questionnaire were shown to be acceptable. Ten significant, and readily interpretable, factors were seen to underlie nurses’ relation to evidence-based practice. Conclusion. Strategies to promote evidence-based practice need to take account of the differing needs of nurses and focus on a range of sources of evidence. The Developing Evidence-Based Practice questionnaire can assist in assessing the specific‘evidencing’ tendencies of any given group of nurses