Theory of Exciton Migration and Field-Induced Dissociation in Conjugated Polymers

The interplay of migration, recombination, and dissociation of excitons in disordered media is studied theoretically in the low temperature regime. An exact expression for the photoluminescence spectrum is obtained. The theory is applied to describe the electric field-induced photoluminescence-quenching experiments by Kersting et al. [Phys. Rev. Lett. 73, 1440 (1994)] and Deussen et al. [Synth. Met. 73, 123 (1995)] on conjugated polymer systems. Good agreement with experiment is obtained using an on-chain dissociation mechanism, which implies a separation of the electron-hole pair along the polymer chain.Comment: 4 pages, RevTeX, 2 Postscript figure

Race and sex: teachers' views on who gets ahead in schools?

The research reported here was part of a large study of the impact of age, disability, race and sex on the teaching profession in England. The basic question asked in this research was how do these factors interact with career aspirations and achievements of classteachers, promoted teachers and headteachers? There were three different data sources: a large postal survey drawn from diverse geographic regions across England with over 2000 respondents; face‐to‐face individual interviews with over 100 teachers in 18 case study schools from across all of the main regions of England; discussions with special interest groups of teachers. Not surprisingly, the answer to the above question was complex. Nonetheless, the paper's conclusion highlights some of the noteworthy themes across this broad sample of teachers from primary, secondary and special schools

The characteristics of adults with upper gastrointestinal bleeding admitted to Tripoli Medical Center: a retrospective case-series analysis

Background: Acute upper gastrointestinal bleeding (UGIB) is a common reason for hospital admissions worldwide. Aetiological causes of UGIB vary according to geographic region and socioeconomic status. However, despite the implementation of early endoscopy as the standard method for the diagnosis and treatment of UGIB, data on the characteristics of patients with UGIB in Libya are still minimal. In this study, we describe patient demographics, aetiological causes for UGIB, and possible risk factors for upper gastrointestinal bleeding in patients admitted to the Gastroenterology Department at Tripoli Medical Center from January 2001 through June 2006. Method: This is a retrospective case-series analysis of all adult patients with upper gastrointestinal bleeding admitted to the Gastroenterology Department at TMC. Patients’ medical records were individually reviewed and relevant data abstracted. Results: A total of 928 cases with diagnoses of UGIB were admitted to Tripoli Medical Center during the study period. Of these cases, 60.3% were males and 39.7% females (3:2) and males were significantly younger than females (49.6 years vs. 53.9 years, p=0.001). The most common cause of UGIB was peptic ulcer (37.1%) of which duodenal ulcer was the most common (30.7% of all UGIB), especially amongst male patients (36.4%). The second most common cause was bleeding due to varices (29.8%), especially amongst females (35.1%). Additionally, smoking and NSAIDs use were reported by 18.6% and 9.7% of cases and both were significantly associated with bleeding due to peptic ulcers. Conclusion: This study has investigated the characteristics of adults with UGIB at a tertiary referral center in Libya. The high frequency of bleeding due to varices amongst females mandates further investigations into the possible underlying hepatic causes and their management, and the potential impact on patient outcome and prognosis.Keywords: bleeding; UGIB; gastroenterology; Liby

Understanding teaching assistant self-efficacy in role and in training: its susceptibility to influence

There has been a noted growth in the number of teaching assistants (TAs) in mainstream schools (DfE, 2013a). Research is inconclusive about their efficacy at changing outcomes for children (Alborz et al 2009; Blatchford et al, 2009) and has proposed more training for TAs (Russell et al, 2005). Generic training models have suggested that enhancing self-efficacy in turn improves performance. This exploratory study investigated factors that may influence TAs’ sense of self-efficacy and its susceptibility to influence in training. Following two modes of mode of school-based training by Educational Psychologists (EPs) data were collected from 14 mainstream secondary school TAs using focus groups. A thematic analysis noted themes regarding self-efficacy, aligned with Bandura’s (1977) sources of information, outcome expectations and whole school support and norms. Review of the data is likely to be able to guide potential trainers to coach consult strategies which are self-efficacy supportive and which address contextual factors including the perceived status of TAs in schools

The role of pre-school quality in promoting resilience in the cognitive development of young children

The study reported here investigates the role of pre-school education as a protective factor in the development of children who are at risk due to environmental and individual factors. This investigation builds upon earlier research by examining different kinds of 'quality' in early education and tests the hypothesis that pre-schools of high quality can moderate the impacts of risks upon cognitive development. Cognitive development was measured in 2857 English pre-schoolers at 36 and 58 months of age, together with 22 individual risks to children's development, and assessments were made of the quality of their pre-school provision. Multilevel Structural Equation Modelling revealed that: the global quality of pre-school can moderate the effects of familial risk (such as poverty); the relationships between staff and children can moderate the effects of child level risk (such as low birth weight); and the specific quality of curricular provision can moderate the effects of both. Policy makers need to take quality into account in their efforts to promote resilience in young 'at risk' children through early childhood services

Multicenter randomized controlled trial on Duration of Therapy for Thrombosis in Children and Young Adults (the Kids-DOTT trial): pilot/feasibility phase findings

BACKGROUND: Randomized controlled trials (RCTs) on pediatric venous thromboembolism (VTE) treatment have been challenged by unsubstantiated design assumptions and/or poor accrual. Pilot/feasibility (P/F) studies are critical to future RCT success. METHODS: The Kids-DOTT trial is a multicenter RCT investigating non-inferiority of a 6-week (shortened) versus 3-month (conventional) duration of anticoagulation in patients aged \u3c 21 years with provoked venous thrombosis. Primary efficacy and safety endpoints are symptomatic recurrent VTE at 1 year and anticoagulant-related, clinically relevant bleeding. In the P/F phase, 100 participants were enrolled in an open, blinded-endpoint, parallel-cohort RCT design. RESULTS: No eligibility violations or randomization errors occurred. Of the enrolled patients, 69% were randomized, 3% missed the randomization window, and 28% were followed in prespecified observational cohorts for completely occlusive thrombosis or persistent antiphospholipid antibodies. Retention at 1 year was 82%. Interobserver agreement between local and blinded central determination of venous occlusion by imaging at 6 weeks after diagnosis was strong (k-statistic = 0.75; 95% confidence interval [CI] 0.48-1.0). The primary efficacy and safety event rates were 3.3% (95% CI 0.3-11.5%) and 1.4% (95% CI 0.03-7.4%). CONCLUSIONS: The P/F phase of the Kids-DOTT trial has demonstrated the validity of vascular imaging findings of occlusion as a randomization criterion, and defined randomization, retention and endpoint rates to inform the fully powered RCT

'Just open your eyes a bit more': The methodological challenges of researching black and minority ethnic students' experiences of physical education teacher education

In this paper we discuss some of the challenges of centralising 'race' and ethnicity in Physical Education (PE) research, through reflecting on the design and implementation of a study exploring Black and minority ethnic students' experiences of their teacher education. Our aim in the paper is to contribute to ongoing theoretical and methodological debates about intersectionality, and specifically about difference and power in the research process. As McCorkel and Myers notes, the 'researchers' backstage'-the assumptions, motivations, narratives and relations-that underpin any research are not always made visible and yet are highly significant in judging the quality and substance of the resulting project. As feminists, we argue that the invisibility of 'race' and ethnicity within Physical Education Teacher Education (PETE), and PE research more widely, is untenable; however, we also show how centralising 'race' and ethnicity raised significant methodological and epistemological questions, particularly given our position as White researchers and lecturers. In this paper, we reflect on a number of aspects of our research 'journey': the theoretical and methodological challenges of operationalising concepts of 'race' and ethnicity, the practical issues and dilemmas involved in recruiting participants for the study, the difficulties of 'talking race' personally and professionally and challenges of representing the experiences of 'others'. © 2012 Copyright Taylor and Francis Group, LLC

Challenges of Early Years leadership preparation: a comparison between early and experienced Early Years practitioners in England

Leadership has been under-researched in the Early Years (EY) sector of primary schools in England, especially in leading change for professional development. The aim of this paper is to theorise what the leadership culture for EY practitioners looks like, and how Initial Teacher Training providers and schools are preparing practitioners for leadership. Using case studies of EY practitioners in different stages of their career in primary schools, we offer an insight into their preparedness for leadership in EY, the implication being that leadership training requires an understanding and embedding of the EY culture and context. Interviews with both sample groups allowed for deeper insight into the lived world. Interviews were also conducted with the head teachers to gain an overview of the leadership preparation they provided. The main findings suggest that newer EY practitioners are better prepared for leadership from their university training in comparison to more experienced EY practitioners

Young children's research: children aged 4-8 years finding solutions at home and at school

Children's research capacities have become increasingly recognised by adults, yet children remain excluded from the academy, with reports of their research participation generally located in adults' agenda. Such practice restricts children's freedom to make choices in matters affecting them, underestimates children’s capabilities and denies children particular rights. The present paper reports on one aspect of a small-scale critical ethnographic study adopting a constructivist grounded approach to conceptualise ways in which children's naturalistic behaviours may be perceived as research. The study builds on multi-disciplinary theoretical perspectives, embracing 'new' sociology, psychology, economics, philosophy and early childhood education and care (ECEC). Research questions include: 'What is the nature of ECEC research?' and 'Do children’s enquiries count as research?' Initially, data were collected from the academy: professional researchers (n=14) confirmed 'finding solutions' as a research behaviour and indicated children aged 4-8 years, their practitioners and primary carers as 'theoretical sampling'. Consequently, multi-modal case studies were constructed with children (n=138) and their practitioners (n=17) in three ‘good’ schools, with selected children and their primary carers also participating at home. This paper reports on data emerging from children aged 4-8 years at school (n=17) and at home (n=5). Outcomes indicate that participating children found diverse solutions to diverse problems, some of which they set themselves. Some solutions engaged children in high order thinking, whilst others did not; selecting resources and trialing activities engaged children in 'finding solutions'. Conversely, when children's time, provocations and activities were directed by adults, the quality of their solutions was limited, they focused on pleasing adults and their motivation to propose solutions decreased. In this study, professional researchers recognised 'finding solutions' as research behaviour and children aged 4-8 years naturalistically presented with capacities for finding solutions; however, the children's encounters with adults affected the solutions they found