1,996 research outputs found
The Discovery of XY Sex Chromosomes in a \u3cem\u3eBoa\u3c/em\u3e and \u3cem\u3ePython\u3c/em\u3e
For over 50 years, biologists have accepted that all extant snakes share the same ZW sex chromosomes derived from a common ancestor [1, 2, 3], with different species exhibiting sex chromosomes at varying stages of differentiation. Accordingly, snakes have been a well-studied model for sex chromosome evolution in animals [1, 4]. A review of the literature, however, reveals no compelling support that boas and pythons possess ZW sex chromosomes [2, 5]. Furthermore, phylogenetic patterns of facultative parthenogenesis in snakes and a sex-linked color mutation in the ball python (Python regius) are best explained by boas and pythons possessing an XY sex chromosome system [6, 7]. Here we demonstrate that a boa (Boa imperator) and python (Python bivittatus) indeed possess XY sex chromosomes, based on the discovery of male-specific genetic markers in both species. We use these markers, along with transcriptomic and genomic data, to identify distinct sex chromosomes in boas and pythons, demonstrating that XY systems evolved independently in each lineage. This discovery highlights the dynamic evolution of vertebrate sex chromosomes and further enhances the value of snakes as a model for studying sex chromosome evolution
Macroinvertebrate abundance and diversity in two ten-year-old created wetlands
The University Archives has determined that this item is of continuing value to OSU's history
Legitimating space: art and the politics of place
Rock art, graffiti, and other emplaced works of art bring people together at specific places. This type of art allows for encounters between people in their absence, and thus presents a range of possibilities for making statements about specific places and those who occupy or visit. This opens the possibility for issues of legitimation to become implicitly or explicitly articulated. However, the legitimate use of space, and the legitimate employment of art, can vary drastically across different contexts. Here, the paper discusses a range of different strategies of art and legitimation in three case studies from India, California, and Spai
Blood ties: ABO is a trans-species polymorphism in primates
The ABO histo-blood group, the critical determinant of transfusion
incompatibility, was the first genetic polymorphism discovered in humans.
Remarkably, ABO antigens are also polymorphic in many other primates, with the
same two amino acid changes responsible for A and B specificity in all species
sequenced to date. Whether this recurrence of A and B antigens is the result of
an ancient polymorphism maintained across species or due to numerous, more
recent instances of convergent evolution has been debated for decades, with a
current consensus in support of convergent evolution. We show instead that
genetic variation data in humans and gibbons as well as in Old World Monkeys
are inconsistent with a model of convergent evolution and support the
hypothesis of an ancient, multi-allelic polymorphism of which some alleles are
shared by descent among species. These results demonstrate that the ABO
polymorphism is a trans-species polymorphism among distantly related species
and has remained under balancing selection for tens of millions of years, to
date, the only such example in Hominoids and Old World Monkeys outside of the
Major Histocompatibility Complex.Comment: 45 pages, 4 Figures, 4 Supplementary Figures, 5 Supplementary Table
Theoretical studies of the historical development of the accounting discipline: a review and evidence
Many existing studies of the development of accounting thought have either been atheoretical or have adopted Kuhn's model of scientific growth. The limitations of this 35-year-old model are discussed. Four different general neo-Kuhnian models of scholarly knowledge development are reviewed and compared with reference to an analytical matrix. The models are found to be mutually consistent, with each focusing on a different aspect of development. A composite model is proposed. Based on a hand-crafted database, author co-citation analysis is used to map empirically the entire literature structure of the accounting discipline during two consecutive time periods, 1972â81 and 1982â90. The changing structure of the accounting literature is interpreted using the proposed composite model of scholarly knowledge development
Postfeminist Media Cultures
This entry provides an overview of postfeminism, which has become central in the last two decades not only within feminist cultural discourse but also within neoliberal discourses and popular culture. The dominant attempts to conceptualize postfeminism often bring to the surface approaches that are complex and contradictory in nature. For instance, postfeminism is viewed as a theoretical framework, as a sensibility, as an expansion of feminist theory, or as a rejection of it. The discussion of postfeminism against the backdrop of media productions further highlights its implications for women and gender representation. A look at quintessential postfeminist texts shows, for instance, that postfeminism essentially problematizes contemporary constructions of gender as it simultaneously evokes and rejects basic feminist tenets
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Highly parallel assays of tissue-specific enhancers in whole Drosophila embryos
Transcriptional enhancers are a primary mechanism by which tissue-specific gene expression is achieved. Despite the importance of these regulatory elements in development, responses to environmental stresses, and disease, testing enhancer activity in animals remains tedious, with a minority of enhancers having been characterized. Here, we have developed âenhancer-FACS-Seqâ (eFS) technology for highly parallel identification of active, tissue-specific enhancers in Drosophila embryos. Analysis of enhancers identified by eFS to be active in mesodermal tissues revealed enriched DNA binding site motifs of known and putative, novel mesodermal transcription factors (TFs). NaĂŻve Bayes classifiers using TF binding site motifs accurately predicted mesodermal enhancer activity. Application of eFS to other cell types and organisms should accelerate the cataloging of enhancers and understanding how transcriptional regulation is encoded within them
Conservatives and the Constabulary in Great Britain: cross-dressing conundrums
Purpose This chapter is devoted to analysing the historical peculiarity of the contemporary British politics of policing. Methodology/approach Research is based on an analysis of policy statements and debates, news reports, and official statistics, in the light of historical studies of the earlier politics of policing. Findings The Conservative governmentâs police reform programme severely diminishes the resources, powers, status and independence of the police, reversing the Toryâs traditional unquestioning support of the police. The package is shown to reflect broader changes in political economy and culture under neoliberalism. Originality/value There has been no previous academic analysis bringing together the various aspects of the reform programme, contrasting it with previous historical understanding of the politics of policing, and linking it to broader contemporary change
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