Identifying Dominant Recombination Mechanisms in Perovskite Solar Cells by Measuring the Transient Ideality Factor

The light ideality factor determined by measuring the open-circuit voltage (V) as a function of light intensity is often used to identify the dominant recombination mechanism in solar cells. Applying this “Suns-V” technique to perovskite cells is problematic since the V evolves with time in a way that depends on the previously applied bias (V), bias light intensity, device architecture and processing route. Here, we show that the dominant recombination mechanism in two structurally similar CH3NH3PbI3 devices containing either mesoporous Al2O3 or TiO2 layers can be identified from the signature of the transient ideality factor following application of a forward bias, V, to the device in the dark. The transient ideality factor is measured by monitoring the evolution of V as a function of time at different light intensities. The initial values of ideality found using this technique are consistent with estimates of the ideality factor obtained from measurements of photoluminescence vs light intensity and electroluminescence vs current density. Time-dependent simulations of the measurement on modeled devices, which include the effects of mobile ionic charge, reveal that this initial value can be correlated to an existing zero-dimensional model while steady-state values must be analyzed taking into account the homogeneity of carrier populations throughout the absorber layer. The analysis shows that Shockley-Read-Hall (SRH) recombination through deep traps at the charge-collection interfaces is dominant in both architectures of measured device. Using transient photovoltage measurements directly following illumination on bifacial devices, we further show that the perovskite–electron-transport-layer interface extends throughout the mesoporous TiO2 layer, consistent with a transient ideality signature corresponding to SRH recombination in the bulk of the film. This method will be useful for identifying performance bottlenecks in alternative variants of perovskite and other mixed ionic-electronic conducting absorber-based solar cells

The Third International Meeting on Genetic Disorders in the RAS/MAPK Pathway: Toward a Therapeutic Approach

The Third International Meeting on Genetic Disorders in the RAS/MAPK Pathway: Towards a Therapeutic Approach was held at the Renaissance Orlando at SeaWorld Hotel (August 2-4, 2013). Seventy-one physicians and scientists attended the meeting, and parallel meetings were held by patient advocacy groups (CFC International, Costello Syndrome Family Network, NF Network and Noonan Syndrome Foundation). Parent and patient advocates opened the meeting with a panel discussion to set the stage regarding their hopes and expectations for therapeutic advances. In keeping with the theme on therapeutic development, the sessions followed a progression from description of the phenotype and definition of therapeutic endpoints, to definition of genomic changes, to identification of therapeutic targets in the RAS/MAPK pathway, to preclinical drug development and testing, to clinical trials. These proceedings will review the major points of discussion

Evaluation of a group based cognitive behavioural therapy programme for menstrual pain management in young women with intellectual disabilities: protocol for a mixed methods controlled clinical trial

BACKGROUND: Menstrual pain which is severe enough to impact on daily activities is very common amongst menstruating females. Research suggests that menstrual pain which impacts on daily functioning may be even more prevalent amongst those with intellectual disabilities. Despite this, little research attention has focused on pain management programmes for those with intellectual disabilities. The aims of this pilot study were to develop and evaluate a theory-based cognitive behavioural therapy (CBT) programme for menstrual pain management in young women with intellectual disabilities. METHODS/DESIGN: The study utilised a mixed methods controlled clinical trial to evaluate elements from a CBT programme called Feeling Better (McGuire & McManus, 2010). The Feeling Better programme is a modular, manualised intervention designed for people with an intellectual disability and their carers. The programme was delivered to 36 young women aged 12 – 30 years who have a Mild - Moderate Intellectual Disability, split between two conditions. The treatment group received the Feeling Better intervention and the control group received treatment as usual. To evaluate the effectiveness of the programme, measures were taken of key pain variables including impact, knowledge, self-efficacy and coping. Process evaluation was conducted to examine which elements of the programme were most successful in promoting change. DISCUSSION: Participants in the intervention group were expected to report the use of a greater number of coping strategies and have greater knowledge of pain management strategies following participation in the intervention and at three month follow-up, when compared to control group participants. A significant advantage of the study was the use of mixed methods and inclusion of process evaluation to determine which elements of a cognitive behavioural therapy programme work best for individuals with intellectual disabilities. TRIAL REGISTRATION: Current Controlled Trials ISRCTN7556775

25th annual computational neuroscience meeting: CNS-2016

The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong

Constrained discretion: New Labour's third way for economic and social policy?

Purpose – This article attempts to unravel the ways in which New Labour's economic and social policies differ from those of previous Conservative and Labour administrations. Design/methodology/approach – The article analyses Treasury documents, which outline the philosophy underpinning the Government's measures. Findings – Gordon Brown has adopted a third-way strategy between Monetarism and Keynesianism, which seeks to maintain stability whilst adapting to shocks. It is based neither upon fixed rules nor complete flexibility, but upon constrained discretion, i.e. the belief that long-term stability requires a comprehensive framework, which constrains policy to achieve sustainable goals, but provides discretion to respond to shocks. If policy-makers possess a sufficiently credible commitment to overall stability, they can exercise discretion in response to shocks without damaging long-run expectations. Originality/value – Founded upon the concept of ‘constrained discretion, the paper argues that New Labour is neither abolishing nor extending the welfare state, but rather is changing its character. Further empirical research in particular sectors is indicated.Economic policy, Polices, Social policy, United Kingdom

Spinning Europe: pro-European union propaganda campaigns in Britain, 1962-1975.

Aimed at an academic as well as a more general readership, this article explores the impact of the concerted propaganda campaigns that were deployed by pro-EU forces at critical junctures in the evolving relationship between Britain and the EU, specifically in 1962 (the first entry attempt), in 1972 (Britain’s accession), and in 1975 (the referendum on continued membership). This is a co-authored piece with Dr Brian Burkitt at the University of Bradford who supervised the PhD from which this arises; approximately 95 per cent of the content is Mullen’s work; and the article is a revised version of an invited paper given at the Political Studies Association Conference at the University of Leeds in April 2005

European integration and the battle for British hearts and minds: New Labour and the Euro

Pro-Europeans have organised three concerted propaganda campaigns to date: in 1962-63 to secure public support following Britain’s first application to join the European Union, in 1970-1 to prepare the public for accession, and in 1974-5 to ensure continued EU membership in the 1975 referendum. This article looks at New Labour’s preparations and strategy for what is likely to be Britain’s fourth concerted pro-European propaganda campaign to ensure a ‘Yes’ vote in a referendum on British membership of the European single currency. The central arguments of this paper are six fold. Firstly, that the state of public opinion on euro membership currently represents an obstacle to the government’s policy of staging and winning a referendum , and joining the single currency. Second, that New Labour’s actual policy on the euro is one of ‘prepare and persuade’ rather than ‘wait and see’. Third, that the central components of the government’s euro referendum strategy can already be identified. Fourth, that – in contrast to the situation before the 1975 referendum – the press is divided on the issue of the euro, supporting both the ‘Yes’ and ‘No’ campaigns. Fifth, that there is an imbalance of forces between the ‘Yes’ and ‘No’ campaigns in favour of the former, but to a lesser extent than during the 1975 referendum. Sixth, that, given the current balance of forces, the government’s success in any euro referendum is by no means assured. The article is divided into seven parts. The first outlines the government’s policy on euro membership. The second considers the first contention – that public opinion on euro membership is currently an obstacle to the government policy – by looking at the state of public opinion polls on the issue. The third presents evidence to support the second contention – that New Labour’s actual policy is one of ‘prepare and persuade’ – by revealing the institutional and legislative preparations for entry that have been made, the two ‘low intensity’ pro-euro propaganda campaigns, and the intervention by external actors to augment those campaigns. The fourth looks at the emerging components of the government’s euro strategy and the possible problems of winning a referendum. The fifth discusses the likely role of the media in a euro referendum propaganda campaign. The sixth looks at the present balance of forces on euro membership. The seventh part concludes