Can the last glacial maximum constrain climate sensitivity?

We investigate the relationship between the Last Glacial Maximum (LGM) and climate sensitivity across the PMIP2 multi-model ensemble of GCMs, and find a correlation between tropical temperature and climate sensitivity which is statistically significant and physically plausible. We use this relationship, together with the LGM temperature reconstruction of Annan and Hargreaves [2012], to generate estimates for the equilibrium climate sensitivity. We estimate the equilibrium climate sensitivity to be about 2.5C with a high probability of being under 4C, though these results are subject to several important caveats. The forthcoming PMIP3/CMIP5 models were not considered in this analysis, as very few LGM simulations are currently available from these models. We propose that these models will provide a useful validation of the correlation presented here

Preferences, preference formation and position taking in a Eurozone out: Lessons from the United Kingdom

In the literature on member state position-taking in the eurozone crisis, the debate has mainly centred on whether national preferences are shaped exclusively within the domestic setting or influenced by shared EU-level norms or interaction within EU institutions. This article goes beyond this discussion. Drawing on original data collected by the authors, it uses the UK’s experience to test the claims both of society-centred approaches, including liberal intergovernmentalism, and perspectives that emphasise the importance of shared EU norms or interaction. It argues that while the first overlook the role of institutions as both actors and mediating variables in preference formation, the second have so far focused on the experience of eurozone members, thereby raising the possibility of selection bias. Treating eurozone form as a series of processes rather than a single event, it contests the claim that preference formation is always driven by societal interests, highlights instances where government acts in the absence of or contrary to expressed societal interests, and reveals limitations of the shared norms critique of liberal intergovernmentalism. It shows that the UK government was driven by a scholars concern to protect the UK economy from financial contagion rather than solidarity with its European partners

The developments of minimum wage legislation in the United Kingdom

This thesis presents an examination of the legal developments made in wage regulations within the United Kingdom. The period that has been chosen for examination spans from the 18th to the 21st century. This period was chosen for examination due to the huge social, political, economic and legal changes that took place within the United Kingdom during these years. These changes saw major developments made within the field of employment law and worker’s rights in general. This period also saw the enactment of the first piece of legislation that regulated wages in the industrial world – the Trade Boards Act of 1909. This thesis examines the journey that the United Kingdom took since the enactment of the 1909 Act that lead to the current system of wage regulation – The National Minimum Wage Act 1998. This thesis has also touched on various campaigns that have called for a Living Wage and has assessed what impact these have had on Government policy. It looks at the National Living Wage, that was introduced in 2016, and examines whether this is a living wage in the sense of the word

Strengthening nonrandomized studies of health communication strategies for HIV prevention.

BACKGROUND: There is growing interest in impact evaluations of health communication (HC) interventions for HIV prevention. Although cluster randomized trials may be optimal in terms of internal validity, they are often unfeasible for political, practical, or ethical reasons. However, a common alternative, the observational study of individuals who do and do not self-report HC intervention exposure, is prone to bias by confounding. Cluster-level quasi-experimental study designs offer promising alternatives to these extremes. METHODS: We identified common rollout strategies for HC initiatives. We mapped these scenarios against established quasi-experimental evaluation designs. We identified key issues for implementers and evaluators if these designs are to be more frequently adopted in HC intervention evaluations with high internal validity. RESULTS: Stronger evaluations will document the planned intervention components in advance of delivery and will implement interventions in clusters according to a predefined systematic allocation plan. We identify 4 types of allocation plan and their associated designs. Where some places get the HC intervention, whereas others do not, a nonrandomized controlled study may be feasible. Where HC is introduced everywhere at a defined point in time, an interrupted time series may be appropriate. Where the HC intervention is introduced in phases, a nonrandomized phased implementation or stepped-wedge design may be used. Finally, where there is variation in strength of implementation of HC, a nonrandomized, dose-response study can be planned. DISCUSSION: Our framework will assist teams planning such evaluations by identifying critical decisions for the implementers and for the evaluators of HC interventions

Timely evaluation in international development

Impact and process evaluations are increasingly used in international development; however they are generally retrospective in outlook. A more timely approach to evaluation aims to identify necessary, feasible and effective changes during a programme or intervention’s lifetime. This paper aims to identify, categorise, describe and critically appraise methods to support more timely evaluation in international development. Potential methods were identified through scoping seminar, public symposium, targeted review of the literature, and the authors’ own experiences and opinions. Findings from the different data sources were reviewed collectively by the author group and triangulated to develop an analytical framework. We identified four purposes of timely evaluation for international development, and critiqued the use of approaches against four dimensions of timeliness and flexibility. Whilst we found significant interest in more timely approaches to evaluation in international development, there was a dearth of published empirical evidence upon which to base strong recommendations. There is significant potential for timely evaluation to improve international development outcomes. New approaches to mixing and adapting existing methods, together with new technologies offer increased potential. Research is needed to provide an empirical evidence base upon which to further develop the application, across sectors and contexts, of timely evaluation in international development

Wave Propagation in Stratified Plasmas.

In this Thesis the theoretical aspects of MHD wave propagation in stratified magnetic flux tubes are studied. In particular the focus is directed firstly to the study of wave propagation in flux tubes with the presence of a background flow and secondly to wave propagation in non-ideal, i.e. viscous, media. Recent observational evidence from the Hinode satellite shows clearly that plasma flows are ubiquitous in the solar atmosphere. Longitudinal and transverse tube waves in flux tubes with a background flow are studied, with the governing equations being derived and solved for a number of footpoint drivers. Applications to the Sun are made and some interesting and important effects on wave propagation are found. The solar atmosphere is widely recognised as a dissipative medium, although most previous studies of wave propagation in stratified atmospheres have assumed an ideal medium. In the second half of the Thesis the effect of viscosity on wave propagation is investigated for both longitudinal and transverse tube waves in a stratified flux tube. The governing equations are derived and solved for both temporal and spatial boundary conditions

Experimental and finite element dynamic analysis of incrementally loaded reinforced concrete structures

This work investigates influence of damage in reinforced concrete (RC) structures on their dynamic properties through modal testing and non-linear finite element (FE) analysis. Five RC beams were designed with the fundamental flexural mode frequencies in the range of 6.5–18.0 Hz for the uncracked state. Mechanical properties of concrete, such as static and dynamic elastic moduli were determined from standard tests and ultra-sonic pulse velocity readings. The beams were incrementally loaded until the span/250 deflection limit was reached and their natural frequencies were measured from the free decay vibrations. The progressive damage reduced fundamental frequencies of tested beams by up to 25%. The non-linear FE analysis was carried out for RC beams and one two-span slab and the calculated reduced frequencies of the 1st and 2nd vibration modes were in excellent agreement with measurements. This led to the conclusion that, given that the non-linear analysis can capture degradation of dynamic stiffness due to cracking, the future dynamic performance and damage identification on the RC structure can be reliably determined from the same FE model. The results reveal potential of the combined modal testing and FE analysis to improve inspection and assessment of the in-service RC structures

The optimal design of stepped wedge trials with equal allocation to sequences and a comparison to other trial designs.

Background/Aims We sought to optimise the design of stepped wedge trials with an equal allocation of clusters to sequences and explored sample size comparisons with alternative trial designs. Methods We developed a new expression for the design effect for a stepped wedge trial, assuming that observations are equally correlated within clusters and an equal number of observations in each period between sequences switching to the intervention. We minimised the design effect with respect to (1) the fraction of observations before the first and after the final sequence switches (the periods with all clusters in the control or intervention condition, respectively) and (2) the number of sequences. We compared the design effect of this optimised stepped wedge trial to the design effects of a parallel cluster-randomised trial, a cluster-randomised trial with baseline observations, and a hybrid trial design (a mixture of cluster-randomised trial and stepped wedge trial) with the same total cluster size for all designs. Results We found that a stepped wedge trial with an equal allocation to sequences is optimised by obtaining all observations after the first sequence switches and before the final sequence switches to the intervention; this means that the first sequence remains in the control condition and the last sequence remains in the intervention condition for the duration of the trial. With this design, the optimal number of sequences is [Formula: see text], where [Formula: see text] is the cluster-mean correlation, [Formula: see text] is the intracluster correlation coefficient, and m is the total cluster size. The optimal number of sequences is small when the intracluster correlation coefficient and cluster size are small and large when the intracluster correlation coefficient or cluster size is large. A cluster-randomised trial remains more efficient than the optimised stepped wedge trial when the intracluster correlation coefficient or cluster size is small. A cluster-randomised trial with baseline observations always requires a larger sample size than the optimised stepped wedge trial. The hybrid design can always give an equally or more efficient design, but will be at most 5% more efficient. We provide a strategy for selecting a design if the optimal number of sequences is unfeasible. For a non-optimal number of sequences, the sample size may be reduced by allowing a proportion of observations before the first or after the final sequence has switched. Conclusion The standard stepped wedge trial is inefficient. To reduce sample sizes when a hybrid design is unfeasible, stepped wedge trial designs should have no observations before the first sequence switches or after the final sequence switches

Iron ochre: a pre-catalyst for the cracking of methane

Background: Iron ochres are gelatinous sludges which can cause problems in terms of water management. In this manuscript, the application of iron ochre obtained from a river has been applied to catalytically crack methane – another potential waste product - into two useful products, hydrogen and a magnetic carbon containing composite.<p></p> Results: The powder XRD pattern of the iron ochre was found to be consistent with the expected 2-line ferrihydrite and EDX analysis showed Fe to be a major component although some Si was present. The sample was observed to contain a fraction with a tubular morphology consistent with the presence of extra-cellular biogenic iron oxide formed by leptothrix. Upon exposure to methane at elevated temperatures, the material was found to transform into an active catalyst for hydrogen production yielding a magnetic carbon containing composite material comprising filamentous carbon and encapsulating graphite.<p></p> Conclusion: The application of two waste products – iron ochre and methane – to generate two useful products – hydrogen and a magnetic carbon containing composite- has been demonstrated. Furthermore, the ochre has been shown to comprise tubular morphology extra-cellular biogenic iron oxide which may be of interest in terms of other applications.<p></p&gt