2,138 research outputs found

    Fabrication and characterizations of proton-exchanged LiNbO3 waveguides fabricated by inductively coupled plasma technique

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    This Letter reports the use of an inductively coupled plasma technique for fabrication of proton-exchanged (PE) LiNbO3 (LN) waveguides. Planar and stripe waveguides have been formed in Y-cut LN which are difficult to obtain with the conventional molten acid method due to the occurrence of surface damage. Secondary ion mass spectrometry, scanning electron microscopy, and infrared absorption spectrum characterization results revealed that a uniform vertical PE profile with a single low order crystal phase has been directly obtained as a result of this unique process. X-ray photoelectron spectroscopy characterization of the treated surface revealed the existence of NbO as the cause for a sometimes darkened surface and confirms the ability to completely restore the surface to LN by oxygen plasma treatment. Atomic force microscopy measurement confirms that good surface quality has been maintained after regeneration of the surface to LN

    Staff perceptions of the success of an alternative curriculum: Skill Force

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    This paper describes staff perceptions of the implementation of an alternative curriculum, skill force, for disaffected pupils in the UK. The perceptions of skill force and school staff were compared based on data from questionnaires completed by 62 skill force and 84 school staff, and interviews with representative samples of each. While the data indicated that the programme had been successful in re-engaging the students with education, the improvement was more marked in relation to the skill force programme than the wider school context.<br/

    Don't classify ratings of affect ; rank them!

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    How should affect be appropriately annotated and how should machine learning best be employed to map manifestations of affect to affect annotations? What is the use of ratings of affect for the study of affective computing and how should we treat them? These are the key questions this paper attempts to address by investigating the impact of dissimilar representations of annotated affect on the efficacy of affect modelling. In particular, we compare several different binary-class and pairwise preference representations for automatically learning from ratings of affect. The representations are compared and tested on three datasets: one synthetic dataset (testing “in vitro”) and two affective datasets (testing “in vivo”). The synthetic dataset couples a number of attributes with generated rating values. The two affective datasets contain physiological and contextual user attributes, and speech attributes, respectively; these attributes are coupled with ratings of various affective and cognitive states. The main results of the paper suggest that ratings (when used) should be naturally transformed to ordinal (ranked) representations for obtaining more reliable and generalisable models of affect. The findings of this paper have a direct impact on affect annotation and modelling research but, most importantly, challenge the traditional state-of-practice in affective computing and psychometrics at large.peer-reviewe

    The incidence and make up of ability grouped sets in the UK primary school

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    The adoption of setting in the primary school (pupils ability grouped across classes for particular subjects) emerged during the 1990s as a means to raise standards. Recent research based on 8875 children in the Millennium Cohort Study showed that 25.8% of children in Year 2 were set for literacy and mathematics and a further 11.2% of children were set for mathematics or literacy alone. Logistic regression analysis showed that the best predictors of being in the top set for literacy or mathematics were whether the child was born in the Autumn or Winter and cognitive ability scores. Boys were significantly more likely than girls to be in the bottom literacy set. Family circumstances held less importance for setting placement compared with the child’s own characteristics, although they were more important in relation to bottom set placement. Children in bottom sets were significantly more likely to be part of a long-term single parent household, have experienced poverty, and not to have a mother with qualifications at NVQ3 or higher levels. The findings are discussed in relation to earlier research and the implications for schools are set out

    Influence of aberrations on confocal-based remote refractive index measurements

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    Confocal scanning combined with low-coherence interferometry is used to provide remote refractive index and thickness measurements of transparent materials. The influence of lens aberrations in the confocal measurement is assessed through ray-trace modeling of the axial point-spread functions generated using optical configurations comprised of paired aspherics and paired achromats. Off-axis parabolic mirrors are suggested as an alternative to lenses and are shown to exhibit much more symmetric profiles provided the system numerical aperture is not too high. The modeled results compare favorably with experimental data generated using an optical instrument comprised of a broadband source and line-scan spectrometer. Refractive index and thickness measurements are made with each configuration with most mirror pairings offering better than twice the repeatability and accuracy of either lens pairing

    Avaliar a validade da avaliação das carteiras de acreditação

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    This study examines one part of a validity argument for portfolio assessments of teaching practice used as an indicator of teaching quality to inform a licensure decision.  We investigate the relationship among portfolio assessment scores, a test of teacher knowledge (ETS’s Praxis I and II),  and changes in student achievement (on Touchstone’s Degrees of Reading Power Test [DRP]).  Key questions are the extent to which the assessment of teaching practice (a) predict gains in students’ achievement and (b) contribute unique information to this prediction beyond what is contributed by the tests of teacher knowledge.  The venue for our study is Connecticut State Department of Education’s (CSDE) support and licensure system for beginning teachers, the Beginning Educator Support and Training (BEST) program (as it was implemented at the time of our study). We investigated whether elementary teachers’ mean effects on their students’ reading achievement support the use of BEST elementary literacy portfolio scores as a measure of teaching quality for licensure, using a data set gathered from both State and two urban school district sources.  The HLM findings indicate that BEST portfolio scores do indeed distinguish among teachers who were more and less successful in enhancing their students’ achievement. An additional analysis indicated that the BEST portfolios add information that is not contained in the Praxis tests, and are more powerful predictors of teachers’ contributions to student achievement gains.Este estudio examina una parte de un argumento de validez para las evaluaciones de los cartera de la práctica docente utilizados como un indicador de la calidad docente para informar una decisión licencia. Investigamos la relación entre los resultados de la evaluación de cartera , una prueba de conocimientos del profesorado ( Praxis I del ETS y II), y los cambios en los logros del estudiante ( en grados de piedra de toque de la prueba eléctrica de la lectura [ DRP ] ) . Las cuestiones clave son la medida en que la evaluación de la práctica docente ( a) predecir las ganancias en el rendimiento de los estudiantes y ( b ) contribuir información única a esta predicción más allá de lo aportado por las pruebas de conocimiento de los maestros . El lugar elegido para nuestro estudio es el Departamento de apoyo y otorgamiento de licencias ( CSDE ) Sistema de Educación para los maestros principiantes del Estado de Connecticut , el Principio Educador , y la programa (BEST ) (como se implementó en el momento de nuestro estudio ) Adiestramiento. Hemos investigado si los "efectos medias en sus alumnos los profesores elementales logros en lectura apoyan el uso de las mejores puntuaciones de la cartera de alfabetización primaria como una medida de calidad de la enseñanza para obtener la licencia , el uso de un conjunto de datos recogidos de Estado y de dos fuentes distrito escolar urbano . Los hallazgos indican que las puntuaciones HLM mejor cartera de hecho distinguen entre los profesores que se encontraban cada vez menos éxito en la mejora de los logros de sus alumnos. Un análisis adicional indicó que los mejores carteras añadir información que no está contenida en las pruebas Praxis , y son más potentes predictores de las contribuciones de los profesores a las ganancias de rendimiento de los estudiantes .O presente estudo analisa uma parte de um argumento de validade para avaliação da carteira de prática de ensino utilizadas como um indicador da qualidade do ensino para informar a decisão de licença. Nós investigamos a relação entre os resultados do portfólio de avaliação, um teste de conhecimentos e competências ( ETS Praxis I e II) , e as mudanças no desempenho do aluno (em graus pedra de toque de teste elétrico leitura [ DRP ] ) . As questões-chave são a medida em que a avaliação da prática docente ( a) prever ganhos no desempenho dos alunos e ( b) contribuir com informações exclusivas para a predição além da evidência fornecida pelo conhecimento dos professores. O local escolhido para o nosso estudo é o suporte Departamento e licenciamento ( CSDE ) Sistema de Educação para professores iniciantes do Estado de Connecticut, o Educador Começando , eo programa (BEST ) (como implementado no momento do nosso estudo ) Treinamento. Nós investigamos se os "efeitos médios em seus professores elementares de leitura os alunos realização apoiar o uso das melhores pontuações da carteira de alfabetização primária como uma medida da qualidade da educação para o licenciamento , o uso de um conjunto de dados coletados fontes do Estado e dois distrito escolar urbano . os resultados indicam que as pontuações melhor portfolio HLM realmente distinguir entre os professores que estavam menos bem sucedido de sempre na melhoria da realização dos seus alunos. Uma análise indicou ainda que os melhores portfolios adicionar informações não contidas nos testes Praxis , e são preditores mais poderosos de contribuições dos professores para os ganhos de desempenho dos alunos

    2D spatially-resolved depth-section microfluidic flow velocimetry using dual beam OCT

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    A dual beam optical coherence tomography (OCT) instrument has been developed for flow measurement that offers advantages over microscope derived imaging techniques. It requires only a single optical access port, allows simultaneous imaging of the microfluidic channel, does not require fluorescent seed particles, and can provide a millimetre-deep depth-section velocity profile (as opposed to horizontal-section). The dual beam instrument performs rapid re-sampling of particle positions, allowing measurement of faster flows. In this paper, we develop the methods and processes necessary to make 2D quantitative measurements of the flow-velocity using dual beam OCT and present exemplar results in a microfluidic chip. A 2D reference measurement of the Poiseuille flow in a microfluidic channel is presented over a spanwise depth range of 700 μm and streamwise length of 1600 μm with a spatial resolution of 10 μm, at velocities up to 50 mm/s. A measurement of a more complex flow field is also demonstrated in a sloped microfluidic section

    Effect of oxygen minimum zone formation on communities of marine protists

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    Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in The ISME Journal 6 (2012): 1586–1601, doi:10.1038/ismej.2012.7.Changes in ocean temperature and circulation patterns compounded by human activities are leading to oxygen minimum zone expansion with concomitant alteration in nutrient and climate active trace gas cycling. Here, we report the response of microbial eukaryote populations to seasonal changes in water column oxygen-deficiency using Saanich Inlet, a seasonally anoxic fjord on the coast of Vancouver Island British Columbia, as a model ecosystem. We combine small subunit ribosomal RNA gene sequencing approaches with multivariate statistical methods to reveal shifts in operational taxonomic units during successive stages of seasonal stratification and renewal. A meta-analysis is used to identify common and unique patterns of community composition between Saanich Inlet and the anoxic/sulfidic Cariaco Basin (Venezuela) and Framvaren Fjord (Norway) to show shared and unique responses of microbial eukaryotes to oxygen and sulfide in these three environments. Our analyses also reveal temporal fluctuations in rare populations of microbial eukaryotes, particularly anaerobic ciliates, that may be of significant importance to the biogeochemical cycling of methane in oxygen minimum zones.This work was performed under the auspices of the US Department of Energy's Office of Science, Biological and Environmental Research Program, and by the University of California, Lawrence Berkeley National Laboratory, Lawrence Livermore National Laboratory under Contract No., and Los Alamos National Laboratory (Contract No. DE-AC02-05CH11231, DE-AC52-07NA27344, DE-AC02-06NA25396), the Natural Sciences and Engineering Research Council (NSERC) of Canada 328256-07 and STPSC 356988, Canada Foundation for Innovation (CFI) 17444; Canadian Institute for Advanced Research (CIFAR), NSF MCB-0348407 to VE, NSF Center for Deep Energy Biosphere Investigations, and the Center for Bioinorganic Chemistry (CEBIC).2012-09-0

    Contemporary medical television and crisis in the NHS

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    This article maps the terrain of contemporary UK medical television, paying particular attention to Call the Midwife as its centrepiece, and situating it in contextual relation to the current crisis in the NHS. It provides a historical overview of UK and US medical television, illustrating how medical television today has been shaped by noteworthy antecedents. It argues that crisis rhetoric surrounding healthcare leading up to the passing of the Health and Social Care Act 2012 has been accompanied by a renaissance in medical television. And that issues, strands and clusters have emerged in forms, registers and modes with noticeable regularity, especially around the value of affective labour, the cultural politics of nostalgia and the neoliberalisation of healthcare
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