72 research outputs found

    Optical and structural properties of dislocations in InGaN

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    Threading dislocations in thick layers of InxGa1−xN (5% < x < 15%) have been investigated by means of cathodoluminescence, time-resolved cathodoluminescence, and molecular dynamics. We show that indium atoms segregate near dislocations in all the samples. This promotes the formation of In-N-In chains and atomic condensates, which localize carriers and hinder nonradiative recombination at dislocations. We note, however, that the dark halo surrounding the dislocations in the cathodoluminescence image becomes increasingly pronounced as the indium fraction of the sample increases. Using transmission electron microscopy, we attribute the dark halo to a region of lower indium content formed below the facet of the V-shaped pit that terminates the dislocation in low composition samples (x < 12%). For x > 12%, the facets of the V-defect featured dislocation bundles instead of the low indium fraction region. In this sample, the origin of the dark halo may relate to a compound effect of the dislocation bundles, of a variation of surface potential, and perhaps, of an increase in carrier diffusion length.ER-C Lindemann Trust Fellowshi

    The sound of street corner society: UK grime music as ethnography

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    This article explores the ways in which popular music can be linked to ethnography. While there is a tradition of connecting popular music with sociology, this article posits a further resonance that is not so much theoretical as methodological. The article suggests that forms of contemporary popular music parallel key facets of ethnography, not simply in terms of sociological analysis, but with regard to popular music as an ethnographic resource, as ‘data’, and as the reflexive expression of Paul Willis’ conception of the ‘ethnographic imagination’; and the article argues that contemporary British hip-hop in the form of ‘grime’ is a potent exemplar. This is due to the resolutely cultural, spatial nature of grime music: a factor that marks out grime as a distinctive musical genre and a distinctive ethnographic form, as it is an experientially rooted music about urban locations, made from within those urban locations

    Language learning and integration of adult Bhutanese refugees : an ethnographic study

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    This study sought a holistic and in-depth investigation of English language learning and integration experiences of a group of adult Bhutanese refugees in Australia. The Bhutanese refugees have settled since 2007 as new residents of their host country after two decades of expatriate life in the refugee camps of Nepal. The impetus for this exploratory study stemmed from my personal experience as a cultural orientation trainer to such refugees and awareness of their expectations, attitudes, and dispositions related to learning and life trajectory. This study is interdisciplinary in its approach that takes account of the complex interplay of language learning and integration. Using an ethnographic methodology as an approach to investigation, this study sought to examine three social spaces of refugees: the family and ethnic community, the host society and the migrant English classroom. The attention was focussed on the resources and constraints the refugees encountered in each of the social spaces. Moreover, various social, contextual, cultural factors, and pre-migration influences embedded in these spaces were explored for their impact on learning and integration. This study was important mainly for three reasons. Through critical examination of the role of refugees’ family and ethnic community networks, it aimed to provide insights into to what extent the resources embedded in these networks can be significant to refugees and also contribute to the existing literature of social capital (Putnam, 2000). Drawing on the investigation of how cultural issues, pre-migration experiences and perceptions of teaching impact on classroom language learning, this study sought to offer insights into how the English language should be taught to the adult students from refugee backgrounds. Moreover, this study sought to extend the scope of the existing refugee integration literature by investigating the integration as a process of ongoing negotiation between ethnocultural retention and host society participation, and how various social, cultural, contextual factors, and pre-migration experiences influenced the way integration is structured in everyday practice. This study employed an ethnographic approach as a methodological framework, involving observations, interviews, and a reflective journal study as the main tools for data collection. The field work was carried out in a regional area of the State of Tasmania. The observations were conducted in the migrant English classrooms, in a multi-ethnic Australian church and in the refugee community; and then the retrospective interviews were carried out with the Bhutanese refugees, their teachers and other service providers. The data were analyzed using ethnographic macro and micro level analysis techniques (Duff, 2002). The findings generated from observation data were supported and triangulated, where possible, by the use of data derived from interviews. This study was informed mainly by the interpretive paradigm. Given how extensive and messy the literature on migrant language learning and integration is, this study utilized a wide range of relevant theories to analyze and interpret the findings derived from the ethnographic fieldwork. One important contribution of this study is the finding that the social capital derived from refugees’ family and ethnic community networks not only enables, but it also inhibits integration. This bonding social capital can function as a coping resource for refugees against the effects of culture shock, language shock, and racism, and can facilitate access to a range of instrumental support and information necessary for successful transition to the host society. However, this study also suggests that an extreme level of embeddedness within the cultural and social frames of ethnic space has the potential to jeopardize individual mobility, host society language learning and sustainable integration. This study shows that the cultural dispositions the adult refugee students bring to the classroom provide the primary basis for the way they approach their English learning, and thus influence their agency and identity as learners. The findings also suggest that the students are likely to engage in the desired learning tasks if their perceptions of teaching quality cohere with the actual teaching they are exposed to. Teachers are therefore suggested to adopt a hybridity of teaching approaches and methods in ways that bridge the gap between their own and their students’ perceptions and expectations. The implications drawn from the empirical results additionally suggest that if the aim of the migrant English program is to facilitate the integration of refugees into their multicultural society, then the pedagogy it embodied should incorporate a hybridity of simulation scenarios (native, non-native and coethnic), enabling them to critically examine the impact of different types of identity they portray and negotiate their identities according to social constraints. This study suggests that in order to understand refugee integration more fully, it is not sufficient to account only for the pre-determined set of objective measures (such as employment and educational outcomes) without considering the way in which integration is actualized in everyday experience. For refugees in this study, what it means to be integrated into the Australian society was complex, ambivalent and context dependent. It was an ongoing process of contestation and negotiation between different values, identities and practices embedded in ethnic and mainstream Australia community. Based on my empirical study, I suggest that the everyday practices of refugee integration resembles with Bhabha’s (1990) notion of “Third Space” and incorporates the hybridity of cultural identifications and experiences

    Allergic Rhinitis and its Associated Co-Morbidities at Bugando Medical Centre in Northwestern Tanzania; A Prospective Review of 190 Cases.

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    Allergic rhinitis is one of the commonest atopic diseases which contribute to significant morbidity world wide while its epidemiology in Tanzania remains sparse. There was paucity of information regarding allergic rhinitis in our setting; therefore it was important to conduct this study to describe our experience on allergic rhinitis, associated co-morbidities and treatment outcome in patients attending Bugando Medical Centre. This was descriptive cross-sectional study involving all patients with a clinical diagnosis of allergic rhinitis at Bugando Medical Centre over a three-month period between June 2011 and August 2011. Data was collected using a pre-tested coded questionnaire and analyzed using SPSS statistical computer software version 17.0. A total of 190 patients were studied giving the prevalence of allergic rhinitis 14.7%. The median age of the patients was 8.5 years. The male to female ratio was 1:1. Adenoid hypertrophy, tonsillitis, hypertrophy of inferior turbinate, nasal polyps, otitis media and sinusitis were the most common co-morbidities affecting 92.6% of cases and were the major reason for attending hospital services. Sleep disturbance was common in children with adenoids hypertrophy (χ2 = 28.691, P = 0.000). Allergic conjunctivitis was found in 51.9%. The most common identified triggers were dust, strong perfume odors and cold weather (P < 0.05). Strong perfume odors affect female than males (χ2 = 4.583, P = 0.032). In this study family history of allergic rhinitis was not a significant risk factor (P =0.423). The majority of patients (68.8%) were treated surgically for allergic rhinitis co morbidities. Post operative complication and mortality rates were 2.9% and 1.6% respectively. The overall median duration of hospital stay of in-patients was 3 days (2 - 28 days). Most patients (98.4%) had satisfactory results at discharge. The study shows that allergic rhinitis is common in our settings representing 14.7% of all otorhinolaryngology and commonly affecting children and adolescent. Sufferers seek medical services due to co-morbidities of which combination of surgical and medical treatment was needed. High index of suspicions in diagnosing allergic rhinitis and early treatment is recommended

    The Role of the Proteinase Inhibitor Ovorubin in Apple Snail Eggs Resembles Plant Embryo Defense against Predation

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    BACKGROUND: Fieldwork has thoroughly established that most eggs are intensely predated. Among the few exceptions are the aerial egg clutches from the aquatic snail Pomacea canaliculata which have virtually no predators. Its defenses are advertised by the pigmented ovorubin perivitellin providing a conspicuous reddish coloration. The nature of the defense however, was not clear, except for a screening for defenses that identified a neurotoxic perivitellin with lethal effect on rodents. Ovorubin is a proteinase inhibitor (PI) whose role to protect against pathogens was taken for granted, according to the prevailing assumption. Through biochemical, biophysical and feeding experiments we studied the proteinase inhibitor function of ovorubin in egg defenses. METHODOLOGY/PRINCIPAL FINDINGS: Mass spectrometry sequencing indicated ovorubin belongs to the Kunitz-type serine proteinase inhibitor family. It specifically binds trypsin as determined by small angle X-ray scattering (SAXS) and cross-linking studies but, in contrast to the classical assumption, it does not prevent bacterial growth. Ovorubin was found extremely resistant to in vitro gastrointestinal proteolysis. Moreover feeding studies showed that ovorubin ingestion diminishes growth rate in rats indicating that this highly stable PI is capable of surviving passage through the gastrointestinal tract in a biologically active form. CONCLUSIONS: To our knowledge, this is the first direct evidence of the interaction of an egg PI with a digestive protease of potential predators, limiting predator's ability to digest egg nutrients. This role has not been reported in the animal kingdom but it is similar to plant defenses against herbivory. Further, this would be the only defense model with no trade-offs between conspicuousness and noxiousness by encoding into the same molecule both the aposematic warning signal and an antinutritive/antidigestive defense. These defenses, combined with a neurotoxin and probably unpalatable factors would explain the near absence of predators, opening new perspectives in the study of the evolution and ecology of egg defensive strategies

    Protocol for the adolescent hayfever trial: cluster randomised controlled trial of an educational intervention for healthcare professionals for the management of school-age children with hayfever

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    <p>Abstract</p> <p>Background</p> <p>Seasonal allergic rhinitis (hayfever) is common and can contribute to a considerable reduction in the quality of life of adolescents. This study aims to examine the effectiveness of standardised allergy training for healthcare professionals in improving disease-specific quality of life in adolescents with hayfever.</p> <p>Methods/Design</p> <p>Adolescents with a history of hayfever registered in general practices in Scotland and England were invited to participate in a cluster randomised controlled trial. The unit of randomisation is general practices.</p> <p>The educational intervention for healthcare professionals consists of a short standardised educational course, which focuses on the management of allergic rhinitis. Patients in the intervention arm of this cluster randomised controlled trial will have a clinic appointment with their healthcare professional who has attended the training course. Patients in the control arm will have a clinic appointment with their healthcare professional and will receive usual care.</p> <p>The primary outcome measure is the change in the Rhinoconjunctivitis Quality of Life Questionnaire with Standardised Activities (RQLQ(S)) score between baseline and six weeks post-intervention in the patient intervention and control groups.</p> <p>Secondary outcome measures relate to healthcare professionals' understanding and confidence in managing allergic rhinitis, changes in clinical practice, numbers of consultations for hayfever and adolescent exam performance.</p> <p>A minimum of 11 practices in each arm of the trial (10 patients per cluster) will provide at least 80% power to demonstrate a minimal clinically important difference of 0.5 in RQLQ(S) score at a significance level of 5% based on an Intraclass Correlation Coefficient (ICC) of 0.02.</p> <p>Discussion</p> <p>At the time of submission, 24 general practices have been recruited (12 in each arm of the trial) and the interventions have been delivered. Follow-up data collection is complete. 230 children consented to take part in the trial; however complete primary outcome data are only available for 160. Further recruitment of general practices and patients will therefore take place in the summer of 2010.</p> <p>Trial Registration</p> <p>Current Controlled Trials ISRCTN95538067</p

    Integration of robotic surgery into routine practice and impacts on communication, collaboration, and decision making: A realist process evaluation protocol

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    Background: Robotic surgery offers many potential benefits for patients. While an increasing number of healthcare providers are purchasing surgical robots, there are reports that the technology is failing to be introduced into routine practice. Additionally, in robotic surgery, the surgeon is physically separated from the patient and the rest of the team, with the potential to negatively impact teamwork in the operating theatre. The aim of this study is to ascertain: how and under what circumstances robotic surgery is effectively introduced into routine practice; and how and under what circumstances robotic surgery impacts teamwork, communication and decision making, and subsequent patient outcomes. Methods and design: We will undertake a process evaluation alongside a randomised controlled trial comparing laparoscopic and robotic surgery for the curative treatment of rectal cancer. Realist evaluation provides an overall framework for the study. The study will be in three phases. In Phase I, grey literature will be reviewed to identify stakeholders' theories concerning how robotic surgery becomes embedded into surgical practice and its impacts. These theories will be refined and added to through interviews conducted across English hospitals that are using robotic surgery for rectal cancer resection with staff at different levels of the organisation, along with a review of documentation associated with the introduction of robotic surgery. In Phase II, a multi-site case study will be conducted across four English hospitals to test and refine the candidate theories. Data will be collected using multiple methods: the structured observation tool OTAS (Observational Teamwork Assessment for Surgery); video recordings of operations; ethnographic observation; and interviews. In Phase III, interviews will be conducted at the four case sites with staff representing a range of surgical disciplines, to assess the extent to which the results of Phase II are generalisable and to refine the resulting theories to reflect the experience of a broader range of surgical disciplines. The study will provide (i) guidance to healthcare organisations on factors likely to facilitate successful implementation and integration of robotic surgery, and (ii) guidance on how to ensure effective communication and teamwork when undertaking robotic surgery

    Conclusion: Reflecting on Studying Evidence Use from a Public Policy Perspective

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    This final chapter reflects on the insights provided by the case studies that constitute this volume, focussing on the key questions which informed the broader research programme from which the cases arise: what does it mean to use evidence effectively to inform health policymaking?; and how do political and institutional factors shape the specific forms of evidence use that arise in different contexts? It discusses the circumstances in which instrumental or strategic uses of evidence were seen; as well as synthesising insights about the ways in which political contestation, the framing and construction of policy problems and their solutions, and different institutional arrangements for policy delivery shape evidence use in different policy contexts. The chapter concludes by considering future areas of research in this field to provide further insights into the use of evidence for health policymaking from a public policy perspective

    ‘Getting the seat of your pants dirty’: space and place in ethnographic educational research

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    In this paper I consider the importance of space and place in ethnographic educational research. The paper draws on research that took place at Educational Video Center (EVC), a non-profit media education centre in New York City (NYC). In this paper I articulate EVC as a place imbued with meaning from the pedagogical practices that take place within and regarding it and argue for a consideration of spatiality in ethnographic educational research. I consider the role of the city landscape in order to identify how knowledge is emplaced and represented through digital, visual technology and conclude by outlining the criticality of spatialising our ethnographic practices
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