16,310 research outputs found
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
Influencing Elections with Statistics: Targeting Voters with Logistic Regression Trees
No full textPolitical campaigning has become a multi-million dollar business. A substantial proportion of a campaign's budget is spent on voter mobilization, i.e., on identifying and
influencing as many people as possible to vote. Based on data, campaigns use statistical
tools to provide a basis for deciding who to target. While the data available is usually rich,
campaigns have traditionally relied on a rather limited selection of information, often including only previous voting behavior and one or two demographical variables. Statistical
procedures that are currently in use include logistic regression or standard classification
tree methods like CHAID, but there is a growing interest in employing modern data mining approaches. Along the lines of this development, we propose a modern framework
for voter targeting called LORET (for logistic regression trees) that employs trees (with
possibly just a single root node) containing logistic regressions (with possibly just an intercept) in every leaf. Thus, they contain logistic regression and classification trees as special
cases and allow for a synthesis of both techniques under one umbrella. We explore various
flavors of LORET models that (a) compare the effect of using the full set of available
variables against using only limited information and (b) investigate their varying effects
either as regressors in the logistic model components or as partitioning variables in the
tree components. To assess model performance and illustrate targeting, we apply LORET
to a data set of 19,634 eligible voters from the 2004 US presidential election. We find that
augmenting the standard set of variables (such as age and voting history) together with
additional predictor variables (such as the household composition in terms of party affiliation and each individual's rank in the household) clearly improves predictive accuracy.
We also find that LORET models based on tree induction outbeat the unpartitioned competitors. Additionally, LORET models using both partitioning variables and regressors
in the resulting nodes can improve the efficiency of allocating campaign resources while
still providing intelligible models.Series: Research Report Series / Department of Statistics and Mathematic
Improving interoperability in distributed and physical union catalogues through co-ordination of cataloguing and indexing policies : report for work package B of the JISC CC-interop project
No full textThis report addresses section 7.2.4 (Guidelines and Strategy for Cataloguing and Indexing Standards) of the CC-interop project plan and fulfills deliverable B3 of work
package B
jDHBenelux Author Template
No full textThis repository contains the latest official GitHub hosted versions of the LaTeX template that authors are required to use when they finalize their contribtions to the DH Benelux Journal. The repository synchronises with the corresponding easy-to-use and well-documented Overleaf Template that provides authors with a low threshold environment for writing LaTeX – but can be used with any LaTeX compiler.
About this Release: Apart from some minor changes to the .cls, v2.0 introduces a number of new files to improve open source development with git and GitHub, including a README, a CC-BY 4.0 License, and a .gitignore file. It also prepares the repository for synchronisation with Zenodo, to improve sustainability.
Full Changelog: https://github.com/DHBenelux/jDHBenelux-author-template/compare/v1.1...v2.
Tree size and herbivory determine below-canopy grass quality and species composition in savannahs
No full textLarge single-standing trees are rapidly declining in savannahs, ecosystems supporting a high diversity of large herbivorous mammals. Savannah trees are important as they support both a unique flora and fauna. The herbaceous layer in particular responds to the structural and functional properties of a tree. As shrubland expands stem thickening occurs and large trees are replaced by smaller trees. Here we examine whether small trees are as effective in providing advantages for grasses growing beneath their crowns as large trees are. The role of herbivory in this positive tree-grass interaction is also investigated. We assessed soil and grass nutrient content, structural properties, and herbaceous species composition beneath trees of three size classes and under two grazing regimes in a South African savannah. We found that grass leaf content (N and P) beneath the crowns of particularly large (ca. 3. 5 m) and very large trees (ca. 9 m) was as much as 40% greater than the same grass species not growing under a tree canopy, whereas nutrient contents of grasses did not differ beneath small trees
Scalar soliton quantization with generic moduli
No full textThis article is distributed under the terms of the Creative Commons
Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in
any medium, provided the original author(s) and source are credArticle funded by SCOAP3. CP is
a Royal Society Research Fellow and partly supported by the U.S. Department of Energy
under grants DOE-SC0010008, DOE-ARRA-SC0003883 and DOE-DE-SC0007897. ABR
is supported by the Mitchell Family Foundation. We would like to thank the Mitchell
Institute at Texas A&M and the NHETC at Rutgers University respectively for hospitality
during the course of this work. We would also like to acknowledge the Aspen Center
for Physics and NSF grant 1066293 for a stimulating research environment which led to
questions addressed in this paper
Binary trees with extremal number of maximal independent sets
No full textA binary tree (more precisely, an unrooted binary tree) is a tree in which all internal vertices (i.e., non-leaves) are exactly of degree 3. We give an upper bound and a lower bound for the number of maximal independent sets in binary trees together with a characterization of the extremal binary trees. The binary trees with second largest number of maximal independent sets are also characterized. (c) 2025 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
A Cantor-Bernstein-type theorem for spanning trees in infinite graphs
No full textWe show that if a graph admits a packing and a covering both consisting of ? many spanning trees, where ? is some infinite cardinal, then the graph also admits a decomposition into ? many spanning trees. For finite ? the analogous question remains open, however, a slightly weaker statement is proved. ? 2021 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).11Nsciescopu
Reconstructing the evolutionary history of the radiation of the land snail genus Xerocrassa on Crete based on mitochondrial sequences and AFLP markers
No full textSauer J, Hausdorf B. Reconstructing the evolutionary history of the radiation of the land snail genus Xerocrassa on Crete based on mitochondrial sequences and AFLP markers. BMC Evolutionary Biology. 2010;10(1): 299.Background: A non-adaptive radiation triggered by sexual selection resulted in ten endemic land snail species of the genus Xerocrassa on Crete. Only five of these species and a more widespread species are monophyletic in a mitochondrial gene tree. The reconstruction of the evolutionary history of such closely related species can be complicated by incomplete lineage sorting, introgression or inadequate taxonomy. To distinguish between the reasons for the nonmonophyly of several species in the mitochondrial gene tree we analysed nuclear AFLP markers. Results: Whereas six of the eleven morphologically delimited Xerocrassa species from Crete are monophyletic in the mitochondrial gene tree, nine of these species are monophyletic in the tree based on AFLP markers. Only two morphologically delimited species could not be distinguished with the multilocus data and might have diverged very recently or might represent extreme forms of a single species. The nonmonophyly of X. rhithymna with respect to X. kydonia is probably the result of incomplete lineage sorting, because there is no evidence for admixture in the AFLP data and the mitochondrial haplotype groups of these species coalesce deeply. The same is true for the main haplotype groups of X. mesostena. The nonmonophyly of X. franciscoi might be the result of mitochondrial introgression, because the coalescences of the haplotypes of this species with some X. mesostena haplotypes are shallow and there is admixture with neighbouring X. mesostena. Conclusion: The most likely causes for the nonmonophyly of species in the mitochondrial gene tree of the Xerocrassa radiation on Crete could be inferred using AFLP data by a combination of several criteria, namely the depth of the coalescences in the gene tree, the geographical distribution of shared genetic markers, and concordance with results of admixture analyses of nuclear multilocus markers. The strongly subdivided population structure increases the effective population size of land snail species and, thus, the likelihood of a long persistence of ancestral polymorphisms. Our study suggests that ancestral polymorphisms are a frequent cause for nonmonophyly of species with a strongly subdivided population structure in gene trees
Immunoglobulin variable-region gene mutational lineage tree analysis: application to autoimmune diseases
No full textLineage trees have frequently been drawn to illustrate diversification, via somatic hypermutation (SHM), of immunoglobulin variable-region (IGV) genes. In order to extract more information from IGV sequences, we developed a novel mathematical method for analyzing the graphical properties of IgV gene lineage trees, allowing quantification of the differences between the dynamics of SHM and antigen-driven selection in different lymphoid tissues, species, and disease situations. Here, we investigated trees generated from published IGV sequence data from B cell clones participating in autoimmune responses in patients with Myasthenia Gravis (MG), Rheumatoid Arthritis (RA), and Sjögren's Syndrome (SS). At present, as no standards exist for cell sampling and sequence extraction methods, data obtained by different research groups from two studies of the same disease often vary considerably. Nevertheless, based on comparisons of data groups within individual studies, we show here that lineage trees from different individual patients are often similar and can be grouped together, as can trees from two different tissues in the same patient, and even from IgG- and IgA-expressing B cell clones. Additionally, lineage trees from most studies reflect the chronic character of autoimmune diseases
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