28,612 research outputs found

    Generalised Umbral Moonshine

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    Umbral moonshine describes an unexpected relation between 23 finite groups arising from lattice symmetries and special mock modular forms. It includes the Mathieu moonshine as a special case and can itself be viewed as an example of the more general moonshine phenomenon which connects finite groups and distinguished modular objects. In this paper we introduce the notion of generalised umbral moonshine, which includes the generalised Mathieu moonshine [Gaberdiel M.R., Persson D., Ronellenfitsch H., Volpato R., Commun. Number Theory Phys. 7 (2013), 145-223] as a special case, and provide supporting data for it. A central role is played by the deformed Drinfel'd (or quantum) double of each umbral finite group GG, specified by a cohomology class in H3(G,U(1))H^3(G,U(1)). We conjecture that in each of the 23 cases there exists a rule to assign an infinite-dimensional module for the deformed Drinfel'd double of the umbral finite group underlying the mock modular forms of umbral moonshine and generalised umbral moonshine. We also discuss the possible origin of the generalised umbral moonshine

    Researching to make a difference: Possibilities for social science research in the age of AIDS

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    HIV and AIDS is recognized as one of the most devastating pandemics of sub-Saharan Africa, and South Africa in particular, with adverse effect on individuals, families, schools, communities and society at large. Research is therefore required to provide a deeper understanding of the complexities of HIV and AIDS in order to mitigate the effect of the pandemic. Much of the excellent research that has been done has been undertaken within a positivist paradigm and has focused on the biomedical aspects of HIV and AIDS, as well as the social aspects of the pandemic. This theoretical position paper draws on various projects in the field of HIV and AIDS education in rural KwaZulu-Natal to argue that more social science research should be framed within a participatory research paradigm, foregrounding participant engagement and process, and which simultaneously has a ‘research-as-intervention’ focus. Such research adheres to the requirement of knowledge production, but also engages the participants as knowledge producers who, through the research process, are enabled to shift towards taking up their own agency. Reflecting on the findings from the various projects suggests that visual participatory methodologies are particularly useful when working with marginalized persons whose voices are seldom heard especially when exploring topics which are difficult to discuss. Furthermore, it brings issues to the fore and opens up debate, while at the same time democratizing research and allowing universities to take up their social responsibility and to contribute towards making a difference in the communities they serve.Keywords: HIV and AIDS, participatory research, visual methodologies, democratizing research, social change, research as interventio

    The swiss army knife of job submission tools: grid-control

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    Grid-control is a lightweight and highly portable open source submission tool that supports virtually all workflows in high energy physics (HEP). Since 2007 it has been used by a sizeable number of HEP analyses to process tasks that sometimes consist of up 100k jobs. grid-control is built around a powerful plugin and configuration system, that allows users to easily specify all aspects of the desired workflow. Job submission to a wide range of local or remote batch systems or grid middleware is supported. Tasks can be conveniently specified through the parameter space that will be processed, which can consist of any number of variables and data sources with complex dependencies on each other. Dataset information is processed through a configurable pipeline of dataset filters, partition plugins and partition filters. The partition plugins can take the number of files, size of the work units, metadata or combinations thereof into account. All changes to the input datasets or variables are propagated through the processing pipeline and can transparently trigger adjustments to the parameter space and the job submission. While the core functionality is completely experiment independent, integration with the CMS computing environment is provided by a small set of plugins.Comment: 8 pages, 7 figures, Proceedings for the 22nd International Conference on Computing in High Energy and Nuclear Physic

    OntoMathPROOntoMath^{PRO} Ontology: A Linked Data Hub for Mathematics

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    In this paper, we present an ontology of mathematical knowledge concepts that covers a wide range of the fields of mathematics and introduces a balanced representation between comprehensive and sensible models. We demonstrate the applications of this representation in information extraction, semantic search, and education. We argue that the ontology can be a core of future integration of math-aware data sets in the Web of Data and, therefore, provide mappings onto relevant datasets, such as DBpedia and ScienceWISE.Comment: 15 pages, 6 images, 1 table, Knowledge Engineering and the Semantic Web - 5th International Conferenc

    Automated identification of Fos expression

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    The concentration of Fos, a protein encoded by the immediate-early gene c-fos, provides a measure of synaptic activity that may not parallel the electrical activity of neurons. Such a measure is important for the difficult problem of identifying dynamic properties of neuronal circuitries activated by a variety of stimuli and behaviours. We employ two-stage statistical pattern recognition to identify cellular nuclei that express Fos in two-dimensional sections of rat forebrain after administration of antipsychotic drugs. In stage one, we distinguish dark-stained candidate nuclei from image background by a thresholding algorithm and record size and shape measurements of these objects. In stage two, we compare performance of linear and quadratic discriminants, nearest-neighbour and artificial neural network classifiers that employ functions of these measurements to label candidate objects as either Fos nuclei, two touching Fos nuclei or irrelevant background material. New images of neighbouring brain tissue serve as test sets to assess generalizability of the best derived classification rule, as determined by lowest cross-validation misclassification rate. Three experts, two internal and one external, compare manual and automated results for accuracy assessment. Analyses of a subset of images on two separate occasions provide quantitative measures of inter- and intra-expert consistency. We conclude that our automated procedure yields results that compare favourably with those of the experts and thus has potential to remove much of the tedium, subjectivity and irreproducibility of current Fos identification methods in digital microscopy

    Career identities of first-year female coloured students

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    It is a well-acknowledged fact that the role of women in society has been changing worldwide over recent decades and South Africa has not been exempt from this trend. Dramatic changes — politically, socially, economically and educationally — have occurred in South Africa since its first democratic, non-racial elections in 1994, which have affected the lives of all citizens. These changes have had major implications for South African women, also regarding their identities. This necessitates a re-evaluation of the prior conceptualisation of identity among women, an issue which has moved from the periphery of academic discourse to the centre. The objective in this research was to explore and describe the career identities of a group of first-year female coloured students in post-apartheid South Africa. A qualitative, explorative, descriptive and contextual research design was implemented. Using purposive sampling, data were collected during six focus group interviews with the students. The findings of the study are presented under four central themes which emerged, namely, the participants' perspectives on career issues; self-knowledge; factors influencing career identities and career choices; and concerns regarding career development. Finally, recommendations are presented in this regard.South African Journal of Education Vol. 27 (1) 2007: pp. 117-13

    Experimental investigation of ultracold atom-molecule collisions

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    Ultracold collisions between Cs atoms and Cs2 dimers in the electronic ground state are observed in an optically trapped gas of atoms and molecules. The Cs2 molecules are formed in the triplet ground state by cw-photoassociation through the outer well of the 0g-(P3/2) excited electronic state. Inelastic atom-molecule collisions converting internal excitation into kinetic energy lead to a loss of Cs2 molecules from the dipole trap. Rate coefficients are determined for collisions involving Cs atoms in either the F=3 or F=4 hyperfine ground state and Cs2 molecules in either highly vibrationally excited states (v'=32-47) or in low vibrational states (v'=4-6) of the a ^3 Sigma_u^+ triplet ground state. The rate coefficients beta ~10^{-10} cm^3/s are found to be largely independent of the vibrational and rotational excitation indicating unitary limited cross sections.Comment: 4 pages, 3 figures, submitted for publicatio
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