Applications of nonlinear viscous-inviscid interactions in liquid layer flows and transonic boundary layer transition

The thesis is divided into two parts. The first is concerned with the fully developed, two-dimensional, free surface flow of a viscous, incompressible fluid over a horizontal surface and down a slope at high Reynolds number. Re. In both cases we concentrate on mechanisms for upstream influence through branching from the relevant basic flow. In the horizontal case it is found that branching can occur and, if the Froude number is sufficiently large, the solution resembles a hydraulic jump. The branching is studied computationally and analytically and the theory is used in a comparison with experiments. For the half-Poiseuille flow on a slope we consider free interactions for a range of gradients, identify when separation can occur and, in the limit of small gradient, find analytic solutions for the flow forced by simple geometries. The flow on larger slopes is addressed computationally. The second part deals with some aspects of boundary layer transition beneath a transonic free stream (Mach number, M, close to unity). Again the emphasis is on high Reynolds number theory and we concentrate on lower branch, Tollmien-Schlichting disturbances. Two unsteady interactions appropriate to transonic flow are studied. The first has M 2-1 ~ 0(Re-1/9) and is an extension of the triple deck structure when the free stream reacts unsteadily. This regime links previously studied subsonic and supersonic cases. Two-dimensional disturbances are little altered but there are new, weakly nonlinear, three-dimensional effects including enhanced growth for slightly oblique disturbances and novel triad interactions. The second has M 2-1 ~ 0(Re-1/9) and links an unsteady, nonlinear free stream, capable of containing shocks, and a quasi-steady boundary layer. The possibility of a resonance linkage between shock buffetting and boundary layer thickening is addressed, being a candidate for a bypass transition mechanism in transonic flows

Europe's future exploration of Main Belt Comets

We discuss possible European missions to explore the recently identified population of "main belt comets", which are small bodies with some asteroid-like properties and some comet-like ones. Various options have been proposed to ESA in recent years, and we will present these, and discuss future possibilities

The Environmental Impacts of International Finance Corporation Lending and Proposals for Reform: A Case Study of Conservation and Oil Development in the Guatemalan Petén

This Article presents a case study of lending by the International Finance Corporation (IFC), the private-sector lending arm of the World Bank Group, in the oil and gas sector in Guatemala. The case study emphasizes the need for additional environmental reform at IFC. With two separate loans in 1994 and 1996, IFC supported the activities of a small international oil company that was operating within a national park in the northern Guatemalan Petdn, an area of rich tropical forests and globally important wetlands. The company\u27s operations had been grandfathered in to the park upon its creation in 1990. Funding from IFC was used to construct a pipeline from the oil field in the park to a refinery outside of the park. The crux of the authors\u27 findings is that the pipeline should have been constructed to follow the path of an existing road, rather than along the chosen route that crosses significant stretches of primary tropical forest and that opened a new right-of-way into a park already facing continued pressure from colonization. The authors conclude that a stronger set of IFC lending policies, combined with a better environmental impact assessment and more extensive public consultation, would have led to a less environmentally damaging outcome. Although the authors acknowledge the complex questions about the role of governments, development agencies, the private sector, conservation organizations, and local communities raised by this issue, they focus on the narrow subject of IFC\u27s role in this matter, stressing the need for a reform agenda at that institution

Public health job advertisements in Australia and New Zealand: a changing landscape

Objective: To describe available public health jobs in Australia and New Zealand by comparing recent job advertisements. Methods: We screened vacancies from 14 online job boards for public health jobs in late 2018. Data collected included information on job titles, sector, contract tenure, location and salary. We compared our findings with those of a job advertisements study from 2005. Results: We found 333 public health job advertisements in Australia and New Zealand. Common roles included project officers, researchers and managers. Nearly 40% of jobs asked for a ‘tertiary’ degree, with an additional 20% requiring a PhD degree. A qualification in public health was considered essential in 13% of job advertisements. Median annual salary range was $95,000–$111,365. Conclusions: There is not one specific public health job. Instead, such jobs are diverse in role, sector, qualification level required and the salary they confer. Implications for public health: There is a demand for skilled workers to perform increasingly complex public health functions, but this may eventually be outpaced by graduate supply. Furthermore, while salaries are considerable, long-term positions are not, and this has implications for the sustainability of the public health workforce

Indicators of pulmonary exacerbation in cystic fibrosis: A Delphi survey of patients and health professionals

Background: There is uncertainty about the most important indicators of pulmonary exacerbations in CF. Methods: Two parallel Delphi surveys in 13 CF centres (UK and Ireland). Delphi 1: 31 adults with CF, ≥ one exacerbation over 12 months. Delphi 2: 38 CF health professionals. Rounds 1 and 2 participants rated their level of agreement with statements relating to indicators of exacerbation; Round 3 participants rated the importance of statements which were subsequently placed in rank order. Results: Objective measurements were of higher importance to health professionals. Feelings of increased debility were rated most important by adults with CF. Conclusions: There were clear differences in perspectives between the two groups as to the most important indicators of an exacerbation. This highlights that CF health professionals should take more cognisance of specific signs and symptoms reported by adults with CF, especially since these may be a precursor to an exacerbation

Intergenerational social mobility and mid-life status attainment: influences of childhood intelligence, childhood social factors, and education

We examined the influences of childhood social background, childhood cognitive ability, and education on intergenerational social mobility and social status attainment at midlife. The subjects were men born in 1921 and who participated in the Scottish Mental Survey of 1932 and thereafter in the Midspan Collaborative study in Scotland between 1970 and 1973. In logistic regression analyses, childhood cognitive ability and height were associated with upward and downward change from father's social class to participant's social class at mid-life. Education significantly influenced upward social mobility. Number of siblings had no significant effect on social mobility. These effects were also examined after adjusting for the other variables. In structural equation modelling analyses, father's social class and childhood cognitive ability influenced social status attainment at midlife, with education and occupational status in young adulthood as partially mediating factors. It was noteworthy that childhood cognitive ability related more strongly to occupation in midlife than to first occupation. These data add to the relatively few studies that track the process of status attainment in adulthood, they provide information from a new geographical setting, and they contain information from a greater proportion of the lifecourse than do most existing studies

Emerging communities of child-healthcare practice in the management of long-term conditions such as chronic kidney disease: Qualitative study of parents' accounts

Background: Parents of children and young people with long-term conditions who need to deliver clinical care to their child at home with remote support from hospital-based professionals, often search the internet for care-giving information. However, there is little evidence that the information available online was developed and evaluated with parents or that it acknowledges the communities of practice that exist as parents and healthcare professionals share responsibility for condition management. Methods. The data reported here are part of a wider study that developed and tested a condition-specific, online parent information and support application with children and young people with chronic-kidney disease, parents and professionals. Semi-structured interviews were conducted with 19 fathers and 24 mothers who had recently tested the novel application. Data were analysed using Framework Analysis and the Communities of Practice concept. Results: Evolving communities of child-healthcare practice were identified comprising three components and several sub components: (1) Experiencing (parents making sense of clinical tasks) through Normalising care, Normalising illness, Acceptance & action, Gaining strength from the affected child and Building relationships to formalise a routine; (2) Doing (Parents executing tasks according to their individual skills) illustrated by Developing coping strategies, Importance of parents' efficacy of care and Fear of the child's health failing; and (3) Belonging/Becoming (Parents defining task and group members' worth and creating a personal identity within the community) consisting of Information sharing, Negotiation with health professionals and Achieving expertise in care. Parents also recalled factors affecting the development of their respective communities of healthcare practice; these included Service transition, Poor parent social life, Psycho-social affects, Family chronic illness, Difficulty in learning new procedures, Shielding and avoidance, and Language and cultural barriers. Health care professionals will benefit from using the communities of child-healthcare practice model when they support parents of children with chronic kidney disease. Conclusions: Understanding some of the factors that may influence the development of communities of child-healthcare practice will help professionals to tailor information and support for parents learning to manage their child's healthcare. Our results are potentially transferrable to professionals managing the care of children and young people with other long-term conditions. © 2014 Carolan et al.; licensee BioMed Central Ltd

Expression of a glycosylphosphatidylinositol-anchored ligand, growth hormone, blocks receptor signalling

We have investigated the interaction between GH (growth hormone) and GHR (GH receptor). We previously demonstrated that a truncated GHR that possesses a transmembrane domain but no cytoplasmic domain blocks receptor signalling. Based on this observation we investigated the impact of tethering the receptor's extracellular domain to the cell surface using a native lipid GPI (glycosylphosphatidylinositol) anchor. We also investigated the effect of tethering GH, the ligand itself, to the cell surface and demonstrated that tethering either the ecGHR (extracellular domain of GHR) or the ligand itself to the cell membrane via a GPI anchor greatly attenuates signalling. To elucidate the mechanism for this antagonist activity, we used confocal microscopy to examine the fluorescently modified ligand and receptor. GH–GPI was expressed on the cell surface and formed inactive receptor complexes that failed to internalize and blocked receptor activation. In conclusion, contrary to expectation, tethering an agonist to the cell surface can generate an inactive hormone receptor complex that fails to internalize