582 research outputs found

    The Effects of ARRA Funding on Broadband Availability and Adoption

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    The American Recovery and Reinvestment Act (ARRA), passed in 2009, provided funds to help the American economy recover from the 2008 economic crisis. More than $7 billion was designated to the advancement of broadband services, and critically, improvement in broadband infrastructure and adoption in underserved areas. This thesis sought to discover if there is a significant causal relationship between the amount of ARRA funding given to a U.S. state and its increase of broadband availability/adoption rates between 2010 (when all ARRA projects were announced), 2013, and 2016 (after all projects were completed). After running various regressions, I found that there is no such relationship between a state’s logarithmic level of ARRA funding and percent increases in either availability or adoption rates. In fact, only one regression displayed any significant causal relationship at all: a negative relationship between funding received and a state’s 2016 adoption rate. The results, explained below, contain lessons for policymakers going forward as society’s dependence on high-speed internet continues to increase

    “Mutual Recognition” and Cross-Border Financial Services in the European Community

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    One of the hallmarks of the European Commission\u27s single market program is the removal of Member State barriers to the provision of financial services throughout the EC. The goal is to make a broad spectrum of banking, securities and insurance services available for everyone. The application of the mutual recognition approach is discussed

    Energy Efficiency Modelling of Residential Air Source Heat Pump Water Heater

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    The heat pump water heater is one of the most energy efficient technologies for heating water for household use. The present work proposes a simplified model of coefficient of performance and examines its predictive capability. The model is based on polynomial functions where the variables are temperatures and the coefficients are derived from the Australian standard test data, using regression technics. The model enables to estimate the coefficient of performance of the same heat pump water heater under other test standards (i.e. US, Japanese, European and Korean standards). The resulting estimations over a heat-up phase and a full test cycle including a draw off pattern are in close agreement with the measured data. Thus the model allows manufacturers to avoid the need to carry out physical tests for some standards and to reduce product cost. The limitations of the methodology proposed are also discussed

    Monitoring induced gene expression of single cells in a multilayer microchip

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    We present a microfluidic system that facilitates long-term measurements of single cell response to external stimuli. The difficulty of addressing cells individually was overcome by using a two-layer microfluidic device. The top layer is designed for trapping and culturing of cells while the bottom layer is employed for supplying chemical compounds that can be transported towards the cells in defined concentrations and temporal sequences. A porous polyester membrane that supports transport and diffusion of compounds from below separates the microchannels of both layers. The performance and potential of the device are demonstrated using human embryonic kidney cells (HEK293) transfected with an inducible gene expression system. Expression of a fluorescent protein (ZsGreen1-DR) is observed while varying the concentration and exposure time of the inducer tetracycline. The study reveals the heterogeneous response of the cells as well as average responses of tens of cells that are analyzed in parallel. The microfluidic platform enables systematic studies under defined conditions and is a valuable tool for general single cell studies to obtain insights into mechanisms and kinetics that are not accessible by conventional macroscopic methods. Figure A two-layer microfluidic device is presented that facilitates measurements of single cell response to external stimul

    The green fields of the mind: Robert Johnson, folk revivalism, and disremembering the American past

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    This thesis seeks to understand the phenomenon of folk revivalism as it occurred in America during several moments in the twentieth and twenty-first centuries. More specifically, I examine how and why often marginalized southern vernacular musicians, especially Mississippi blues singer Robert Johnson, were celebrated during the folk revivals of the 1930s and 1960s as possessing something inherently American, and differentiate these periods of intense interest in the traditional music of the American South from the most recent example of revivalism early in the new millennium. In the process, I suggest the term disremembering to elucidate the ways in which the intent of some vernacular traditions, such as blues music, has often been redirected towards a different social or political purpose when communities with divergent needs in a stratified society have convened around a common interest in cultural practice

    Preparation of neuronal co-cultures with single cell precision

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    Microfluidic embodiments of the Campenot chamber have attracted great interest from the neuroscience community. These interconnected co-culture platforms can be used toinvestigate a variety of questions, spanning developmental and functional neurobiology to infection and disease propagation. However, conventional systems require significant cellular inputs (many thousands per compartment), inadequate for studying low abundance cells, such as primary dopaminergic substantia nigra, spiral ganglia and Drosophilia melanogaster neurons, and impractical for high throughput experimentation. The dense cultures are also highly locally entangled, with few outgrowths (<10%) interconnecting the two cultures. In this paper straightforward microfluidic and patterning protocols are described which address these challenges: (i) a microfluidic single neuron arraying method, and (ii) a water masking method for plasma patterning biomaterial coatings to register neurons and promote outgrowth between compartments. Minimalistic neuronal co-cultures were prepared with high-level (>85%) inter-compartment connectivity and can be used for high throughput neurobiology experiments with single cell precisio

    Investigating tools and techniques for improving software performance on multiprocessor computer systems

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    The availability of modern commodity multicore processors and multiprocessor computer systems has resulted in the widespread adoption of parallel computers in a variety of environments, ranging from the home to workstation and server environments in particular. Unfortunately, parallel programming is harder and requires more expertise than the traditional sequential programming model. The variety of tools and parallel programming models available to the programmer further complicates the issue. The primary goal of this research was to identify and describe a selection of parallel programming tools and techniques to aid novice parallel programmers in the process of developing efficient parallel C/C++ programs for the Linux platform. This was achieved by highlighting and describing the key concepts and hardware factors that affect parallel programming, providing a brief survey of commonly available software development tools and parallel programming models and libraries, and presenting structured approaches to software performance tuning and parallel programming. Finally, the performance of several parallel programming models and libraries was investigated, along with the programming effort required to implement solutions using the respective models. A quantitative research methodology was applied to the investigation of the performance and programming effort associated with the selected parallel programming models and libraries, which included automatic parallelisation by the compiler, Boost Threads, Cilk Plus, OpenMP, POSIX threads (Pthreads), and Threading Building Blocks (TBB). Additionally, the performance of the GNU C/C++ and Intel C/C++ compilers was examined. The results revealed that the choice of parallel programming model or library is dependent on the type of problem being solved and that there is no overall best choice for all classes of problem. However, the results also indicate that parallel programming models with higher levels of abstraction require less programming effort and provide similar performance compared to explicit threading models. The principle conclusion was that the problem analysis and parallel design are an important factor in the selection of the parallel programming model and tools, but that models with higher levels of abstractions, such as OpenMP and Threading Building Blocks, are favoured

    Taxonomic decomposition of the latitudinal gradient in species diversity of North American floras

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    Aim: To test the latitudinal gradient in plant species diversity for self-similarity across taxonomic scales and amongst taxa. Location: North America. Methods: We used species richness data from 245 local vascular plant floras to quantify the slope and shape of the latitudinal gradients in species diversity (LGSD) across all plant species as well as within each family and order. We calculated the contribution of each family and order to the empirical LGSD. Results: We observed the canonical LGSD when all plants were considered with floras at the lowest latitudes having, on average, 451 more species than floras at the highest latitudes. When considering slope alone, most orders and families showed the expected negative slope, but 31.7% of families and 27.7% of orders showed either no significant relationship between latitude and diversity or a reverse LGSD. Latitudinal patterns of family diversity account for at least 14% of this LGSD. Most orders and families did not show the negative slope and concave-down quadratic shape expected by the pattern for all plant species. A majority of families did not make a significant contribution in species to the LGSD with 53% of plant families contributing little to nothing to the overall gradient. Ten families accounted for more than 70% of the gradient. Two families, the Asteraceae and Fabaceae, contributed a third of the LGSD. Main Conclusions: The empirical LGSD we describe here is a consequence of a gradient in the number of families and diversification within relative few plant families. Macroecological studies typically aim to generate models that are general across taxa with the implicit assumption that the models are general within taxa. Our results strongly suggest that models of the latitudinal gradient in plant species richness that rely on environmental covariates (e.g. temperature, energy) are likely not general across plant taxa
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