Effects in polarimetry of interference within wave plates

Multiple-beam interference within wave plates is investigated in terms of the detrimental effects it produces in the data of stellar spectropolarimetry. It is noted that spectral fringe structures occur in the phase delay, the polarizance and, for Pancharatnam designs, the reference axis of the wave plate. The natures of the problems are exposed by considering typical wave plates and experimental procedures used in linear and circular spectropolarimetry. It is demonstrated that the chief bane of accurate measurements is the presence of polarizance fringes, but which can be alleviated by the choice of experimental procedure. For spectral circular polarization studies, problems of cross-talk from any linear polarization present in the source are especially severe. In principle the effects of fringing can be removed in data reductions by calibration measurements of a set of linear polarization standard stars displaying different vibration azimuths and, for circular polarization measurements, knowledge of the linear polarization characteristics of the investigated star must also be known

Experiments with a novel CCD stellar polarimeter

Experiments and observations have been undertaken with "bread-board" equipment to explore the potential of a "ring" stellar polarimeter with a CCD camera, rather than photographic plates used in Treanor's (1968) original instrument. By spreading the polarimetric signal over a large number of pixels on the detector, design prediction suggests that the polarimetric accuracy could be ~Δρ±0.00001 or ±0.001% per frame or even better. Although the photon accumulations suggest that this was achieved, instabilities in the employed crude modulator system provided frame to frame measurements with a greater than expected scatter. Software was developed to reduce the data in a simple way. With a design using more professional components and perhaps with more sophisticated reduction procedures, the full potential of the method should be achievable with the prospect of high precision polarimetry of the brighter stars. As an experimental bonus, the employed CCD chip was found to be free from any measurable polarizational sensitivity

Sediment-macrophyte relationships in lowland English rivers: using macrophytes for biological assessment

PhDA study of the relationship between submerged-rooted aquatic macrophytes and the chemical and physical characteristics of sediments in lowland British rivers is described. The focus of the research is the spatial variability of nutrient concentrations in river sediments and the preferences of particular macrophyte species for different sediment types. This information is required to further develop the use of macrophytes in the biological assessment of rivers. Sediment samples were collected from beneath macrophyte stands and unvegetated areas of the riverbed in 17 rivers. The sediment samples were analysed for total and inorganic phosphorus, total nitrogen, organic carbon, organic matter and silt-clay content. Data on water chemistry flow regimes, channel geometry and macrophyte habitat were also collected. Sediments were found to exhibit a high degree of variability both within 100m sites and between the different rivers, particularly with respect to phosphorus concentrations. There were relationships between sediment concentrations of total and inorganic phosphorus and between concentrations of total nitrogen, organic carbon and organic matter. No clear relationships between mean values for sediment parameters and either water column nutrient concentrations or flow regime were apparent. The significance of the sediment variables as a control on macrophyte community structure was investigated through the use of canonical ordination and discriminant analysis. Macrophyte species showed broad tolerances to all sediment variables and it was not possible to separate the influence of sediment nutrients from other sediment parameters or differences between rivers. Comparisons of water sediment and plant tissue nutrient concentrations at sites upstream and downstream of waste water treatment work outfalls on two rivers indicated that the discharges affected both the water and sediment concentrations but not plant tissue levels. The research suggests that the relationships between macrophytes and sediments in lowland rivers are complex and confounded by the effect of the plants themselves upon flow and sediment dynamics

Government Performance and Life Satisfaction in Contemporary Britain

This paper investigates relationships between public policy outcomes and life satisfaction in contemporary Britain. Monthly national surveys gathered between April 2004 and December 2008 are used to analyze the impact of policy delivery both at the micro and macro levels, the former relating to citizens personal experiences, and the latter to cognitive evaluations of and affective reactions to the effectiveness of policies across the country as a whole. The impact of salient political events and changes in economic context involving the onset of a major financial crisis also are considered. Analyses reveal that policy outcomes, especially microlevel ones, significantly influence life satisfaction. The effects of both micro- and macrolevel outcomes involve both affective reactions to policy delivery and cognitive judgments about government performance. Controlling for these and other factors, the broader economic context in which policy judgments are made also influences life satisfaction. © 2010 Southern Political Science Association

Given its likely adverse political effects, the problem of social care funding is unlikely to be solved any time soon

Paul Whiteley, Harold Clarke, and Marianne Stewart write that a large increase in funding for social care would mean a significant hike in taxation, largely paid for by the young and the middle-aged with the elderly being the beneficiaries. This would create political problems for all parties

Vulnerable Americans rally around a president in a crisis. but polarization means this hasn’t happened during the Covid-19 pandemic.

Historically in times of crisis, presidents experience a polling boost as Americans ‘rally around the flag’, but this has not been the case during President Trump’s handling of the COVID-19 pandemic. In new analysis, Harold Clarke, Marianne Stewart and Paul Whiteley find that the massive partisan and ideological differences in the electorate meant that the expected spike in Trump’s support did not occur – especially among the most vulnerable, who would ordinarily be more likely to rally around the president

How the Conservatives’ austerity rhetoric won them GE2015, and almost cost them GE2017

Paul Whiteley, Harold D. Clarke, and Marianne Stewart explain why austerity is no longer an election winner – neither economically nor politically. They argue that David Cameron’s government reaped political rewards through its austerity rhetoric, but the strategy backfired in the next election, when many voters believed a Conservative government would impose more hardship on them

In Canada’s snap election, Justin Trudeau and the Liberals were both victims and beneficiaries of the COVID-19 crisis

Last month, Canada held its second election in less than two years as Liberal Prime Minister, Justin Trudeau sought a new mandate during the COVID-19 pandemic. But Trudeau’s gamble that Canadians would reward his party for its handling of the pandemic did not pay off, and he now still leads a minority government. Using new survey data, Harold Clarke, Thomas J. Scotto and Marianne C. Stewart find that while Canadian voters did approve of the government’s pandemic response, concerns about its handling of the economy and inflation deprived the Liberal party of an election majority

The Economic and Electoral Consequences of Austerity Policies in Britain

The aim of this paper is to examine the relationship between electoral support and the economy over the period 2004 to 2014, paying particular attention to the impact of the economic strategy pursued by the Coalition government in Britain since the general election in May 2010. This involves modelling the relationship between voting intentions, perceptions of economic performance, and a variety of other variables using survey data collected each month from 2004. The evidence shows that when Labour was in office, support for the party was strongly influenced by the state of the economy, as was support for the opposition parties. However, since the Coalition came to power, the relationship between the economy and political support has changed, with neither the Conservatives nor the Liberal Democrats gaining from a fairly rapid growth in economic optimism which has taken place since early 2013. The paper explains this change in terms of a growing perception among the public that none of the major parties can effectively manage Britain?s economic problems. It is also the case that optimism about the national economy has not significantly percolated down to the level of the individual voter. So individuals may be more optimistic about the future of the national economy but they are still being badly affected by the recession