275 research outputs found

    COMPOSE: Compacted object sample extraction a framework for semi-supervised learning in nonstationary environments

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    An increasing number of real-world applications are associated with streaming data drawn from drifting and nonstationary distributions. These applications demand new algorithms that can learn and adapt to such changes, also known as concept drift. Proper characterization of such data with existing approaches typically requires substantial amount of labeled instances, which may be difficult, expensive, or even impractical to obtain. In this thesis, compacted object sample extraction (COMPOSE) is introduced - a computational geometry-based framework to learn from nonstationary streaming data - where labels are unavailable (or presented very sporadically) after initialization. The feasibility and performance of the algorithm are evaluated on several synthetic and real-world data sets, which present various different scenarios of initially labeled streaming environments. On carefully designed synthetic data sets, we also compare the performance of COMPOSE against the optimal Bayes classifier, as well as the arbitrary subpopulation tracker algorithm, which addresses a similar environment referred to as extreme verification latency. Furthermore, using the real-world National Oceanic and Atmospheric Administration weather data set, we demonstrate that COMPOSE is competitive even with a well-established and fully supervised nonstationary learning algorithm that receives labeled data in every batch

    Nucleotide Sequence Variation within the PI3K p85 Alpha Gene Associates with Alcohol Risk Drinking Behaviour in Adolescents

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    While the phosphatidylinositol 3-kinase (PI3K)-dependent signaling pathway is typically known to regulate cell growth and survival, emerging evidence suggest a role for this pathway in regulating the behavioural responses to addictive drugs.To investigate whether PI3K contributes to patterns of risky alcohol drinking in human, we investigated genetic variations in PIK3R1, encoding the 85 kD regulatory subunit of PIK, in 145 family trios consisting of 15-16 year old adolescents and their parents. Screening for mutations in exons, exon-intron boundaries and regulatory sequences, we identified 14 single nucleotide polymorphisms (SNPs) in the PIK3R1 gene region from exon 1 to the beginning of the 3' untranslated region (UTR). These SNPs defined haplotypes for the respective PIK3R1 region. Four haplotype tagging (ht)SNPs (rs706713, rs2302975, rs171649 and rs1043526), discriminating all haplotypes with a frequency >or=4.5% were identified. These htSNPs were used to genotype adolescents from the "Mannheim Study of Risk Children" (MARC). Transmission disequilibrium tests in these adolescents and their parents demonstrated sex-specific association of two SNPs, rs2302975 and rs1043526, with patterns of risky alcohol consumption in male adolescents, including lifetime prevalence of drunkenness (p = 0.0019 and 0.0379, respectively) and elevated maximum amount of drinking (p = 0.0020 and 0.0494, respectively), as a measure for binge drinking pattern.Our findings highlight a previously unknown relevance of PIK3R1 genotypes for alcohol use disorders and might help discriminate individuals at risk for alcoholism

    Nazi Punks Folk Off: Leisure, Nationalism, Cultural Identity and the Consumption of Metal and Folk Music

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    Far-right activists have attempted to infiltrate and use popular music scenes to propagate their racialised ideologies. This paper explores attempts by the far right to co-opt two particular music scenes: black metal and English folk. Discourse tracing is used to explore online debates about boundaries, belonging and exclusion in the two scenes, and to compare such online debates with ethnographic work and previous research. It is argued that both scenes have differently resisted the far right through the policing of boundaries and communicative choices, but both scenes are compromised by their relationship to myths of whiteness and the instrumentality of the pop music industry

    Whiteness, Blackness and Settlement: Leisure and the Integration of New Migrants

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    At times of economic uncertainty the position of new migrants is subject to ever closer scrutiny. While the main focus of attention tends to be on the world of employment the research on which this paper is based started from the proposition that leisure and sport spaces can support processes of social inclusion yet may also serve to exclude certain groups. As such, these spaces may be seen as contested and racialised places that shape behaviour. The paper draws on interviews with White migrants from Poland and Black migrants from Africa to examine the normalising of whiteness. We use this paper not just to explore how leisure and sport spaces are encoded by new migrants, but how struggles over those spaces and the use of social and cultural capital are racialised

    Managing and monitoring equality and diversity in UK sport: An evaluation of the sporting equals Racial Equality Standard and its impact on organizational change

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    Despite greater attention to racial equality in sport in recent years, the progress of national sports organizations toward creating equality of outcomes has been limited in the United Kingdom. The collaboration of the national sports agencies, equity organizations and national sports organizations (including national governing bodies of sport) has focused on Equality Standards. The authors revisit an earlier impact study of the Racial Equality Standard in sport and supplement it with another round of interview material to assess changing strategies to manage diversity in British sport. In particular, it tracks the impact on organizational commitment to diversity through the period of the establishment of the Racial Equality Standard and its replacement by an Equality Standard that deals with other diversity issues alongside race and ethnicity. As a result, the authors question whether the new, generic Equality Standard is capable of addressing racial diversity and promoting equality of outcomes. © 2006 Sage Publications

    Visual ecology of aphids – a critical review on the role of colours in host finding

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    We review the rich literature on behavioural responses of aphids (Hemiptera: Aphididae) to stimuli of different colours. Only in one species there are adequate physiological data on spectral sensitivity to explain behaviour crisply in mechanistic terms. Because of the great interest in aphid responses to coloured targets from an evolutionary, ecological and applied perspective, there is a substantial need to expand these studies to more species of aphids, and to quantify spectral properties of stimuli rigorously. We show that aphid responses to colours, at least for some species, are likely based on a specific colour opponency mechanism, with positive input from the green domain of the spectrum and negative input from the blue and/or UV region. We further demonstrate that the usual yellow preference of aphids encountered in field experiments is not a true colour preference but involves additional brightness effects. We discuss the implications for agriculture and sensory ecology, with special respect to the recent debate on autumn leaf colouration. We illustrate that recent evolutionary theories concerning aphid–tree interactions imply far-reaching assumptions on aphid responses to colours that are not likely to hold. Finally we also discuss the implications for developing and optimising strategies of aphid control and monitoring

    A Real Time Metridia Luciferase Based Non-Invasive Reporter Assay of Mammalian Cell Viability and Cytotoxicity via the β-actin Promoter and Enhancer

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    Secreted reporter molecules offer a means to evaluate biological processes in real time without the need to sacrifice samples at pre-determined endpoints. Here we have adapted the secreted bioluminescent reporter gene, Metridia luciferase, for use in a real-time viability assay for mammalian cells. The coding region of the marine copepod gene has been codon optimized for expression in human cells (hMLuc) and placed under the control of the human β-actin promoter and enhancer. Metridia luciferase activity of stably transfected cell models corresponded linearly with cell number over a 4-log dynamic range, detecting as few as 40 cells. When compared to standard endpoint viability assays, which measure the mitochondrial dehydrogenase reduction of tetrazolium salts, the hMLuc viability assay had a broader linear range of detection, was applicable to large tissue culture vessels, and allowed the same sample to be repeatedly measured over several days. Additional studies confirmed that MLuc activity was inhibited by serum, but demonstrated that assay activity remained linear and was measurable in the serum of mice bearing subcutaneous hMLuc-expressing tumors. In summary, these comparative studies demonstrate the value of humanized Metridia luciferase as an inexpensive and non-invasive method for analyzing viable cell number, growth, tumor volume, and therapeutic response in real time

    Renouncing the Single Image: Photography and the Realism of Abstraction

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    This essay addresses the issue of the relationship between abstraction and realism that it argues is at stake in the rejection of any primacy accorded to the single image, in favour of a sequencing of photographs according to certain, often novelistic and epic ideas of narrative form. Setting out from the opening text of Allan Sekula’s Fish Story, the article explores the competing tendencies towards what Georg Lukács termed ‘narration’ and ‘description’ as these are traced throughout Sekula's project (in part through a comparison with the contrasting works of Andreas Gursky). The essay concludes by suggesting the ways in which it is the irreducible actuality of abstraction within the concrete everydayness of capitalism's social world that means that all photographic ‘realism’ is intrinsically ‘haunted’ by a certain spectre of that ‘self-moving substance in the ‘shape of money’, as Marx calls it, or of the abstract form of capital itself
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