Investigation of the Rasch model in its application to foreign language proficiency testing

The main theme of this study is the use of the Rasch model for dichotomously-scored items in the analysis of second/foreign language proficiency test data. Analytic procedures deriving from this model are applied to response data from English proficiency tests of two different types: (i) a cloze-type test, which embodies the notion of proficiency as being measurable by a single, global test, and (ii) the objectively-scored sections of the English Language. Testing Service (ELTS) test,, in which proficiency is. viewed as being divisible into sub-components, each measured by a separate subtest. The total numbers of testees involved are 854 and 1,503 respectively. The theoretical background relating to item response models is first explained, via "a discussion of traditional procedures for the analysis of test data. The relationship between the Rasch model and other response models of similar mathematical form is considered, and further details of its operation provided. The results of the Rasch analyses are compared with those from traditional analyses of the same data. The Rasch statistics are shown to be more informative, and therefore preferable, on several counts. Further investigations are carried out on both data sets, in order to assess the fit between model and data, to check for possible violations of specific model assumptions, and, to check for, expected model features. For, both the cloze-type data, and the ELTS, data (analysed in separate subtests), observed and expected item characteristic curves show reasonable conformity, though with some Instances of serious misfit In both cases. No evidence for departure from unidimensionality is found for the cloze data, but there is some indication that ELTS modules, when combined withGeneral components, may vary in their departure from unidimensionality

Nineteenth century synthetic textile dyes. Their history and identification on fabric

Textile dyes have been the subject of many studies from the varied perspectives of historians, conservators and scientists. Most of these have focused on natural compounds but nineteenth century synthetic dyes form the basis of this thesis. The dual areas of interest have been the social history of those dyes developed between the introduction of Mauveine in 1856 and the end of the century and the investigation of novel spectroscopic methods for their identification in situ on textiles.Although the first synthetic dye was manufactured in England, the centre of the industry soon moved to Germany and Switzerland. Education and contacts in Switzerland or Germany were important in advancement in the field as can be seen in the previously unresearched biography of J.J. Hummel who, through his Swiss step-father, was able to travel to Zurich to study and subsequently progressed from working as a cotton printer to become the first professor of textile dyeing at the Yorkshire College, later Leeds University.Evidence was found in newspapers and popular periodicals for three other factors which had an important influence on the attitude to synthetic dyes in England. One was English reluctance to invest in speculative ventures rather than the established textile industries. The second was the possession of colonial holdings and overseas trade networks which encouraged continued research into imported natural products. Thirdly the particular form of the Arts and Crafts movement in England emphasised the craft means of production in a way which the equivalent aesthetic in Germany did not. Nineteenth century dye manuals show that there was no exclusive use of either natural or synthetic dyes in the trade despite the fashion in artistic circles for ‘natural’ colours.The identification of synthetic dyes on textiles is important in textile history and conservation especially in the context supplied by the investigations described above into the usage of the dyes. It is highly desirable in the field of cultural heritage to devise analytical techniques which are non-destructive and non-sampling. Dyed wool and silk samples were prepared using 12 dye compounds. Different techniques were tested and Fourier transform Raman spectroscopy was able to provide diagnostic spectra for a variety of synthetic dyes. Clear features in the spectra could be used to identify the dye class and to distinguish between dyes of the same class. This technique allowed the detection of dyes on the textile for the first time and it was applied successfully to original samples from dye manuals. One unknown mauve sample was also analysed and a combination of infrared and Raman spectroscopy allowed a definite identification of the dye as a triphenylmethane and tentatively as Methyl violet.This study combines investigations into material culture and social history and demonstrates the use of science together with historical research to reveal new insights into the history of textile dyes

Scenarios for the development of smart grids in the UK: synthesis report

‘Smart grid’ is a catch-all term for the smart options that could transform the ways society produces, delivers and consumes energy, and potentially the way we conceive of these services. Delivering energy more intelligently will be fundamental to decarbonising the UK electricity system at least possible cost, while maintaining security and reliability of supply. Smarter energy delivery is expected to allow the integration of more low carbon technologies and to be much more cost effective than traditional methods, as well as contributing to economic growth by opening up new business and innovation opportunities. Innovating new options for energy system management could lead to cost savings of up to £10bn, even if low carbon technologies do not emerge. This saving will be much higher if UK renewable energy targets are achieved. Building on extensive expert feedback and input, this report describes four smart grid scenarios which consider how the UK’s electricity system might develop to 2050. The scenarios outline how political decisions, as well as those made in regulation, finance, technology, consumer and social behaviour, market design or response, might affect the decisions of other actors and limit or allow the availability of future options. The project aims to explore the degree of uncertainty around the current direction of the electricity system and the complex interactions of a whole host of factors that may lead to any one of a wide range of outcomes. Our addition to this discussion will help decision makers to understand the implications of possible actions and better plan for the future, whilst recognising that it may take any one of a number of forms

Agricultural and Water Harvesting Opportunities in Kenya, via a Crowd-Sourced, Citizen Science Hybrid Paradigm

This is potential joint collaborative research between the Purdue University and citizens of Kenya via the Global Engineering Program in the areas of agriculture in water harvesting. Specifically, in the rural part of Kenya, outside of Nairobi, lives can be greatly impacted. Libraries of tomorrow will have global capacity and responsibility to serve all aspects of global citizenry. Herein is one possible Kenyan example. In partnership with the Tinmore Institute, an International Food, Water, and Energy Security team of experts, such international collaboration with Purdue\u27s Global Engineering program could be quite successful within the areas of agricultural and water security sustainability. Moreover, Purdue’s expertise and reputation as a global leader in research and scholarship can be further demonstrated

Power contours : optimising sample size and precision in experimental psychology and human neuroscience

When designing experimental studies with human participants, experimenters must decide how many trials each participant will complete, as well as how many participants to test. Most discussion of statistical power (the ability of a study design to detect an effect) has focussed on sample size, and assumed sufficient trials. Here we explore the influence of both factors on statistical power, represented as a two-dimensional plot on which iso-power contours can be visualised. We demonstrate the conditions under which the number of tri- als is particularly important, i.e. when the within-participant variance is large relative to the between-participants variance. We then derive power contour plots using existing data sets for eight experimental paradigms and methodologies (including reaction times, sensory thresholds, fMRI, MEG, and EEG), and provide example code to calculate estimates of the within- and between-participant variance for each method. In all cases, the within-participant variance was larger than the between-participants variance, meaning that the number of trials has a meaningful influence on statistical power in commonly used paradigms. An online tool is pro- vided (https://shiny.york.ac.uk/powercontours/) for generating power contours, from which the optimal combination of trials and participants can be calculated when designing future studies

Transport of proteins into the various subcompartments of mitochondria

The import of proteins into mitochondria is an intricate process comprised of multiple steps. The first step involves the sorting of cytosolically synthesized precursor proteins to the mitochondrial surface. There precursor proteins are recognized by specific receptors which deliver them to the general import site present in the outer membrane. The second stage of import involves a series of complex intraorganelle sorting events which results in the delivery of the proteins to one of the four possible submitochondrial destinations, namely the outer and inner membranes, the matrix and intermembrane space. Here in this review, we discuss the current knowledge on these intramitochondrial sorting events. We especially focus on targetting of proteins to the intermembrane space. Sorting to the intermembrane space represents a particularly interesting situation, as at least three separate targetting pathways to this subcompartment are known to exist

A simple method for determination of plasma and urinary biotin

Measurement of biotin in plasma and urine has been stimulated by recent descriptions of inborn errors of biotin metabolism and by newly recognized causes of biotin deficiency. Biotin determination in physiologic fluids to document these conditions has been hindered by lack of a widely useable assay. This paper presents a method which employs tritium-labelled biotin, avidin, and nitrocellulose filters to measure urinary and plasma biotin in a rapid and simple manner.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23871/1/0000110.pd