20,813 research outputs found

    Evaluating the Historical Accuracy of Blackwork Embroidery with Fractal Analysis

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    The intricate monochromatic embroidery that graced the collars and cuffs of Renaissance nobility and domestic materials from that era has been little studied beyond the historical costuming and crafting communities. This style, known as blackwork, for it was traditionally done in black silk on white linen, exemplifies how complex and visually-appealing designs can arise from repetition of simple forms, often demonstrating the fractal property of self-similarity. Though most blackwork patterns are not true fractals, fractal analysis offers a means of objectively quantifying their complexity and new lens through which to examine this embroidery technique. The purpose of this study was to look for trends that could be used to evaluate the historical accuracy of blackwork patterns. Images of historical patterns from the Renaissance period, historically-inspired, and modern patterns were gathered from eight published books on blackwork. The fractal dimensions of these patterns were calculated using FracLac, a fractal analysis plugin for the ImageJ software. Subsequent statistical analyses revealed several significant differences between the fractal dimensions of patterns for fillings, borders, and complete projects. Though there was some variation, a trend noted was that Renaissance-era patterns had a fractal dimension around 1.75

    Constitutively Active Galpha q and Galpha 13 Trigger Apoptosis through Different Pathways

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    We investigated the effect of expression of constitutively active Galpha mutants on cell survival. Transfection of constitutively active Galphaq and Galpha13 in two different cell lines caused condensation of genomic DNA and nuclear fragmentation. Endonuclease cleavage of genomic DNA was followed by labeling the DNA fragments and subsequent flow cytometric analysis. The observed cellular phenotype was identical to the phenotype displayed by cells undergoing apoptosis. To distinguish between the apoptosis-inducing ability of the two Galpha-subunits, the signaling pathways involved in this cellular function were investigated. Whereas Galpha q induced apoptosis via a protein kinaseC-dependent pathway, Galpha13 caused programmed cell death through a pathway involving the activation of the small G-protein Rho. Both of the pathways leading to apoptosis were blocked by overexpression of bcl-2. In contrast to other apoptosis-inducing systems, expression of constitutively active Galphaq and Galpha13 triggered apoptosis in high serum as well as in defined medium

    Constraint-based Sequential Pattern Mining with Decision Diagrams

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    Constrained sequential pattern mining aims at identifying frequent patterns on a sequential database of items while observing constraints defined over the item attributes. We introduce novel techniques for constraint-based sequential pattern mining that rely on a multi-valued decision diagram representation of the database. Specifically, our representation can accommodate multiple item attributes and various constraint types, including a number of non-monotone constraints. To evaluate the applicability of our approach, we develop an MDD-based prefix-projection algorithm and compare its performance against a typical generate-and-check variant, as well as a state-of-the-art constraint-based sequential pattern mining algorithm. Results show that our approach is competitive with or superior to these other methods in terms of scalability and efficiency.Comment: AAAI201

    A responsabilidade tributária do administrador judicial

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    Sumário: I. Introdução; II. Responsabilidade tributária; III. Normas jurídicas; IV. O CIRE; V. O estatuto do administrador judicial; VI. A posição da Autoridade Tributária; VII. Jurisprudência; VIII. A reforma do CIRE em 2012; IX. Conclusão

    Mining Companies and CSR in Guinea: Use the U.N. Global Compact Model to Improve Lives

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    Mining Companies tend to exploit natural resources in developing countries such as Guinea, to the detriment of the local population (Amaeshi, Adi, Ogbechie,& Amao,2007); (Kefee, 2013); (Hamann, 2003). Government officials in such countries often do not work in the better interests of the citizens due to corruption and other factors (Ayoade, 2011); (Kefee, 2013); (Susson, 2012). In this study the writer presents library-research material on the social, economic, and environmental impact of selective mining companies in Guinea, and the complexities introduced by the actions of local government officials. The writer presents recommendations for improving the interests of the natives of Guinea based on the Corporate Social Responsibility (CSR) model of the United Nations Global Compact (UNGC)

    The status of environmental education in elementary and middle public schools of East Tennessee : a teacher perspective

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    Worldwide efforts are being made to improve the quality of human life and the quality of the environment. In order to achieve these ends, educators must prepare individuals to become environmentally literate citizens and well-informed decision-makers in a fast changing technological world. This descriptive study used surveys to determine the status of environmental education in East Tennessee school systems as perceived by elementary and middle school teachers. Through this study, information was provided about what is being done and what needs to be done to improve environmental education in the State of Tennessee. A valid and reliable instrument, developed and used in Wisconsin, was mailed to 958 elementary and middle school teachers who were randomly selected from 316 schools in 33 East Tennessee public school systems. Out of the 958 surveys mailed, 432 were returned. The research findings suggest that teachers believe that it is important to take time to integrate environmental concepts and issues into subjects and at all grade levels of elementary and middle schools. Teachers indicated that a lack of resources/funding was the primary reason they do not infuse education about the environment into their curriculum. Over two-thirds of the respondents never received either pre- or in-service training in environmental education. In addition, this study also revealed that teachers would infuse environmental education into their curriculum if they had better access to resources/aids for teaching environmental concepts. In light of the results of this study, most teacher education programs in East Tennessee are not providing environmental education courses to pre- and in-service teachers who, in general, have positive attitudes toward teaching environmental education concepts in elementary and middle schools. Moreover, teachers in East Tennessee generally are not equipped with the knowledge and skills needed to successfully integrate environmental education into their curricula

    Transcriptionally inactive oocyte-type 5S RNA genes of Xenopus laevis are complexed with TFIIIA in vitro

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    An extract from whole oocytes of Xenopus laevis was shown to transcribe somatic-type 5S RNA genes approximately 100-fold more efficiently than oocyte-type 5S RNA genes. This preference was at least 10-fold greater than the preference seen upon microinjection of 5S RNA genes into oocyte nuclei or upon in vitro transcription in an oocyte nuclear extract. The approximately 100-fold transcriptional bias in favor of the somatic-type 5S RNA genes observed in vitro in the whole oocyte extract was similar to the transcriptional bias observed in developing Xenopus embryos. We also showed that in the whole oocyte extract, a promoter-binding protein required for 5S RNA gene transcription, TFIIIA, was bound both to the actively transcribed somatic-type 5S RNA gene and to the largely inactive oocyte-type 5S RNA genes. These findings suggest that the mechanism for the differential expression of 5S RNA genes during Xenopus development does not involve differential binding of TFIIIA to 5S RNA genes
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