27,652 research outputs found

    Information Apprenticeship: Integrating Faith and Learning in the Library

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    Librarianship is built on information. As we proceed further into the 21st century, librarians need to understand the concept of “information” as it cannot be easily defined. This paper presents a brief overview of information theory and reviews several concepts proposed by non-librarians. Also, these ideas, when viewed from a Christian perspective can help our understanding of “information.” A review of related scriptures is also included

    Expanded Parameters in the Self-Organized Critical Forest Fire Model

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    The forest fire model has frequently been used as a way to test the theory of Self-Organized Criticality, which is a model of complexity. The model analyzes commonalities in randomly generated forest fires using a computer simulation. In previous models, only the nearest neighbors to a tree on fire catch on fire, and it has been assumed that if further neighboring trees also catch on fire, then it will still exhibit self-organized criticality. Testing this assumption aids to the exploration of the applicability of self-organized criticality because the model is the most useful when it applies to a large range of systems, as closely related to nature as possible

    Group algebras and enveloping algebras with nonmatrix and semigroup identities

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    Let K be a field of positive characteristic p, let R be either a group algebra K[G] or a restricted enveloping algebra u(L), and let I be the augmentation ideal of R. We first characterize those R for which I satisfies a polynomial identity not satisfied by the algebra of all 2-by-2 matrices over K. Then we examine those R for which I satisfies a semigroup identity (that is, a polynomial identity which can be written as the difference of two monomials).Comment: 11 pages. Written in LaTeX2

    Activation of human NK cells by Plasmodium-infected red blood cells.

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    This chapter describes a protocol to assess activation of human NK cells following in vitro stimulation with malaria-infected red blood cells. Activation is assessed by flow cytometry, staining for cell surface expression of CD69 and accumulation of intracellular IFN-Îł. Procedures are described for in vitro propagation and purification of Plasmodium falciparum parasites, separation of peripheral blood mononuclear cells from heparinized blood by density centrifugation, in vitro culture of PBMC and for staining and analysis of PBMC by flow cytometry. Some examples of typical FACS plots are shown

    Extrinsic versus intrinsic diameter for Riemannian filling-discs and van Kampen diagrams

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    The diameter of a disc filling a loop in the universal covering of a Riemannian manifold may be measured extrinsically using the distance function on the ambient space or intrinsically using the induced length metric on the disc. Correspondingly, the diameter of a van Kampen diagram filling a word that represents the identity in a finitely presented group can either be measured intrinsically its 1-skeleton or extrinsically in the Cayley graph of the group. We construct the first examples of closed manifolds and finitely presented groups for which this choice -- intrinsic versus extrinsic -- gives rise to qualitatively different min-diameter filling functions.Comment: 44 pages, 12 figures, to appear in the Journal of Differential Geometr

    Long-term evolution of highly alkaline steel slag drainage waters

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    © 2015, Springer International Publishing Switzerland. The disposal of slag generated by the steel industry can have negative consequences upon the surrounding aquatic environment by the generation of high pH waters, leaching of potentially problematic trace metals, and rapid rates of calcite precipitation which smother benthic habitats. A 36-year dataset was collated from the long-term ambient monitoring of physicochemical parameters and elemental concentrations of samples from two steel slag leachate-affected watercourses in northern England. Waters were typified by elevated pH ( > 10), high alkalinity, and were rich in dissolved metals (e.g. calcium (Ca), aluminium (Al), and zinc (Zn)). Long-term trend analysis was performed upon pH, alkalinity, and Ca concentration which, in addition to Ca flux calculations, were used to highlight the longevity of pollution arising as a result of the dumping and subsequent leaching of steel slags. Declines in calcium and alkalinity have been modest over the monitoring period and not accompanied by significant declines in water pH. If the monotonic trends of decline in alkalinity and calcium continue in the largest of the receiving streams, it will be in the region of 50–80 years before calcite precipitation would be expected to be close to baseline levels, where ecological impacts would be negligible

    The Potential for Public-Private Partnerships: Philanthropic Leaders Considering Housing as a Platform

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    Explores foundation leaders' approaches to housing as a platform for layering programs and services to improve quality of life, views on funding partnerships with the federal government, and suggestions for targeted collaborations. Includes case studies

    Comparison of spectrum occupancy measurements using software defined radio RTL-SDR with a conventional spectrum analyzer approach

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    In the present day Cognitive Radio has become a realistic option for solution of the spectrum scarcity problem in wireless communication. Recently, the TV band has attracted attention due to the considerable potential for exploitation of available TV white space which is not utilized based on time and location. In this paper, we investigate spectrum occupancy of the UHF TV band in the frequency range from 470 to 862MHz by using two different devices, the low cost device RTL-SDR and high cost spectrum analyzer. The spectrum occupancy measurements provide evidence of the utility of using the inexpensive RTL SDR and illustrate its effectiveness for detection of the percentage of spectrum utilization compared with results from the conventional high cost Agilent spectrum analyzer, both systems employing various antennas
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