In situ observation of stress relaxation in epitaxial graphene

Upon cooling, branched line defects develop in epitaxial graphene grown at high temperature on Pt(111) and Ir(111). Using atomically resolved scanning tunneling microscopy we demonstrate that these defects are wrinkles in the graphene layer, i.e. stripes of partially delaminated graphene. With low energy electron microscopy (LEEM) we investigate the wrinkling phenomenon in situ. Upon temperature cycling we observe hysteresis in the appearance and disappearance of the wrinkles. Simultaneously with wrinkle formation a change in bright field imaging intensity of adjacent areas and a shift in the moire spot positions for micro diffraction of such areas takes place. The stress relieved by wrinkle formation results from the mismatch in thermal expansion coefficients of graphene and the substrate. A simple one-dimensional model taking into account the energies related to strain, delamination and bending of graphene is in qualitative agreement with our observations.Comment: Supplementary information: S1: Photo electron emission microscopy and LEEM measurements of rotational domains, STM data of a delaminated bulge around a dislocation. S2: Movie with increasing brightness upon wrinkle formation as in figure 4. v2: Major revision including new experimental dat

Theology at the University of Pretoria - 100 years: (1917-2017) Past, present and future

In this scholarly book, a century’s theology presented by the Faculty of Theology at the University of Pretoria, is celebrated. All authors are academics or research associates of the University of Pretoria. A historical and futuristic overview with perspectives from the past, present and future, are examined. The past is not only portrayed by means of societal and scientific contributions and achievements, but the authors also reflect on malfunctions, ill behaviour and disappointments of church and theology, presented at the University of Pretoria within the South African context over 100 years. The book commences with a chapter in which institutional transformation is discussed, as well as the changes that demonstrate the role of the Faculty of Theology within a secular state university. It includes an explanation of the importance of research impact, research productivity and research reputation. Among various discipline indicators, the category Theology and Religion Studies plays a significant role in the measurement of world university rankings of universities. With regard to scientific and encyclopaedic content, the book focuses on the theological disciplines presented in the academic curricula: first the biblical sciences (Old and New Testament Studies), then the historical disciplines (Systematic Theology, Church History and Church Polity), and finally the practical disciplines (Practical Theology, Science of Religion and Missiology). The role of Religion Studies in a newly established Faculty of Theology and Religion not only enhances the diversity of interreligious tolerance and an atmosphere of dialogue, but it serves as platform to interconnect with the fields of Humanities, Social and Natural Sciences and other academic disciplines. In the conclusive part of the book, contributions highlight the role of the centres in the Faculty (Centre for Contextual Ministry and Centre for Sustainable Communities), as well as the continental and international footprints of the two theological journals whose title ownership is attached to the Faculty of Theology of the University of Pretoria, namely HTS Theological Studies and Verbum et Ecclesia. The methodology comprised in all the chapters amounts to a literature and contextual study. Since the book describes the histories of formal academic departments, these texts are of a descriptive, interpretative and critical character. Reference is made in some chapters to exegetical methods, like the historical critical methods. The target audience of the book is academic scholars and theologians, who specialise in the different fields of Theology, the Humanities and other Social Sciences. The book is also accessible to scholars of other academic disciplines outside these disciplines. The book comprises original research by several authors and is not plagiarised from other scientific publications of this nature

Kissing G Domains of MnmE Monitored by X-Ray Crystallography and Pulse Electron Paramagnetic Resonance Spectroscopy

The authors of this research article demonstrate the nature of the conformational changes MnmE was previously suggested to undergo during its GTPase cycle, and show the nucleotide-dependent dynamic movements of the G domains around two swivel positions relative to the rest of the protein. These movements are of crucial importance for understanding the mechanistic principles of this GAD

Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.

The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD

Dynamics of social class contempt in contemporary British television comedy

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 Taylor & Francis.British television comedy has often ridiculed the complexities and characteristics of social class structures and identities. In recent years, poor white socially marginalised groups, now popularly referred to as “chavs”, have become a prevalent comedy target. One of the most popular and controversial television “comedy chavs” is Little Britain's fictional teenage single mother, Vicky Pollard. This article examines the representation of Vicky Pollard in light of contemporary widespread abuse of the white working class. Highlighting the polysemic and ambivalent nature of Vicky Pollard's representation, the article argues that whilst Little Britain's characterisation of Vicky Pollard largely contributes to contemporary widespread demonisation of the working class, there are moments within Little Britain when a more sympathetic tone towards the poor working class may be read, and where chav identities are used to ridicule the pretensions, superficiality, and falsity of middle-class identities. The article concludes that television comedy has been, and continues to be, a significant vehicle through which serious concerns, anxieties, and questions about social class and class identities are discursively constructed and contested

Evaluation of immunological escape mechanisms in a mouse model of colorectal liver metastases

<p>Abstract</p> <p>Background</p> <p>The local and systemic activation and regulation of the immune system by malignant cells during carcinogenesis is highly complex with involvement of the innate and acquired immune system. Despite the fact that malignant cells do have antigenic properties their immunogenic effects are minor suggesting tumor induced mechanisms to circumvent cancer immunosurveillance. The aim of this study is the analysis of tumor immune escape mechanisms in a colorectal liver metastases mouse model at different points in time during tumor growth.</p> <p>Methods</p> <p>CT26.WT murine colon carcinoma cells were injected intraportally in Balb/c mice after median laparotomy using a standardized injection technique. Metastatic tumor growth in the liver was examined by standard histological procedures at defined points in time during metastatic growth. Liver tissue with metastases was additionally analyzed for cytokines, T cell markers and Fas/Fas-L expression using immunohistochemistry, immunofluorescence and RT-PCR. Comparisons were performed by analysis of variance or paired and unpaired <it>t </it>test when appropriate.</p> <p>Results</p> <p>Intraportal injection of colon carcinoma cells resulted in a gradual and time dependent metastatic growth. T cells of regulatory phenotype (CD4+CD25+Foxp3+) which might play a role in protumoral immune response were found to infiltrate peritumoral tissue increasingly during carcinogenesis. Expression of cytokines IL-10, TGF-β and TNF-α were increased during tumor growth whereas IFN-γ showed a decrease of the expression from day 10 on following an initial increase. Moreover, liver metastases of murine colon carcinoma show an up-regulation of FAS-L on tumor cell surface with a decreased expression of FAS from day 10 on. CD8+ T cells express FAS and show an increased rate of apoptosis at perimetastatic location.</p> <p>Conclusions</p> <p>This study describes cellular and macromolecular changes contributing to immunological escape mechanisms during metastatic growth in a colorectal liver metastases mouse model simulating the situation in human cancer.</p

Finding needles in haystacks:Linking scientific names, reference specimens and molecular data for Fungi

DNA phylogenetic comparisons have shown that morphology-based species recognition often underestimates fungal diversity. Therefore, the need for accurate DNA sequence data, tied to both correct taxonomic names and clearly annotated specimen data, has never been greater. Furthermore, the growing number of molecular ecology and microbiome projects using high-throughput sequencing require fast and effective methods for en masse species assignments. In this article, we focus on selecting and re-annotating a set of marker reference sequences that represent each currently accepted order of Fungi. The particular focus is on sequences from the internal transcribed spacer region in the nuclear ribosomal cistron, derived from type specimens and/or ex-type cultures. Reannotated and verified sequences were deposited in a curated public database at the National Center for Biotechnology Information (NCBI), namely the RefSeq Targeted Loci (RTL) database, and will be visible during routine sequence similarity searches with NR_prefixed accession numbers. A set of standards and protocols is proposed to improve the data quality of new sequences, and we suggest how type and other reference sequences can be used to improve identification of Fungi.The Intramural Research Programs of the National Center for Biotechnology Information, National Library of Medicine and the National Human Genome Research Institute, both at the National Institutes of Health.http://www.ncbi.nlm.nih.gov/bioproject/PRJNA177353am201