Gas seepage and seismogenic structures along the North Anatolian Fault in the eastern Sea of Marmara

We carried out a combined geophysical and gas-geochemical survey on an active fault strand along the North Anatolian Fault (NAF) system in the Gulf of İzmit (eastern Sea of Marmara), providing for the first time in this area data on the distribution of methane (CH4) and other gases dissolved in the bottom seawater, as well as the CH4isotopic composition. Based on high-resolution morphobathymetric data and chirp-sonar seismic reflection profiles we selected three areas with different tectonic features associated to the NAF system, where we performed visual and instrumental seafloor inspections, including in situ measurements of dissolved CH4, and sampling of the bottom water. Starting from background values of 2–10 nM, methane concentration in the bottom seawater increases abruptly up to 20 nM over the main NAF trace. CH4 concentration peaks up to ∼120 nM were detected above mounds related probably to gas and fluids expulsion. Methane is microbial (δ13CCH4: −67.3 and −76‰ versus VPDB), and was found mainly associated with pre-Holocene deposits topped by a 10–20 m thick draping of marine mud. The correlation between tectonic structures and gas-seepages at the seafloor suggests that the NAF in the Gulf of İzmit could represent a key site for long-term combined monitoring of fluid exhalations and seismicity to assess their potential as earthquake precursors

The dynamics of language and ethnicity in Mauritius

The link between ethnicity and language has been well established in research but its contextual, perspectual and variable nature demands that this connection be re-examined in each attempt to understand a nation. This paper is about Mauritius, a postcolonial context where French and British colonisation has left salient features which continue to influence the dynamics around language and ethnicity in the country. By describing its demographic characteristics and its linguistic and political situation, I retrieve some of the key facets of this multi-ethnic and multi-lingual nation which evidence resistance by both the state and the populace against the established colonial languages. To compensate for the lack of appropriate theoretical framework in existing research on Mauritius, I use Homi Bhabha’s postcolonial theoretical framework to uncover the realities faced by both the state and the people of this country and the impacts these may have in the workplace

Endogenous antigen processing drives the primary CD4+ T cell response to influenza.

By convention, CD4+ T lymphocytes recognize foreign and self peptides derived from internalized antigens in combination with major histocompatibility complex class II molecules. Alternative pathways of epitope production have been identified, but their contributions to host defense have not been established. We show here in a mouse infection model that the CD4+ T cell response to influenza, critical for durable protection from the virus, is driven principally by unconventional processing of antigen synthesized within the infected antigen-presenting cell, not by classical processing of endocytosed virions or material from infected cells. Investigation of the cellular components involved, including the H2-M molecular chaperone, the proteasome and γ-interferon-inducible lysosomal thiol reductase revealed considerable heterogeneity in the generation of individual epitopes, an arrangement that ensures peptide diversity and broad CD4+ T cell engagement. These results could fundamentally revise strategies for rational vaccine design and may lead to key insights into the induction of autoimmune and anti-tumor responses

Reaction mechanism for the replacement of calcite by dolomite and siderite: Implications for geochemistry, microstructure and porosity evolution during hydrothermal mineralisation

Carbonate reactions are common in mineral deposits due to CO2-rich mineralising fluids. This study presents the first in-depth, integrated analysis of microstructure and microchemistry of fluid-mediated carbonate reaction textures at hydrothermal conditions. In doing so, we describe the mechanisms by which carbonate phases replace one another, and the implications for the evolution of geochemistry, rock microstructures and porosity. The sample from the 1.95 Moz Junction gold deposit, Western Australia, contains calcite derived from carbonation of a metamorphic amphibole—plagioclase assemblage that has further altered to siderite and dolomite. The calcite is porous and contains iron-rich calcite blebs interpreted to have resulted from fluid-mediated replacement of compositionally heterogeneous amphiboles. The siderite is polycrystalline but nucleates topotactically on the calcite. As a result, the boundaries between adjacent grains are low-angle boundaries (<10°), which are geometrically similar to those formed by crystal–plastic deformation and recovery. Growth zoning within individual siderite grains shows that the low-angle boundaries are growth features and not due to deformation. Low-angle boundaries develop due to the propagation of defects at grain faces and zone boundaries and by impingement of grains that nucleated with small misorientations relative to each other during grain growth.The cores of siderite grains are aligned with the twin planes in the parent calcite crystal showing that the reactant Fe entered the crystal along the twin boundaries. Dolomite grains, many of which appear to in-fill space generated by the siderite replacement, also show alignment of cores along the calcite twin planes, suggesting that they did not grow into space but replaced the calcite. Where dolomite is seen directly replacing calcite, it nucleates on the Fe-rich calcite due to the increased compatibility of the Fe-bearing calcite lattice relative to the pure calcite. Both reactions are interpreted as fluid-mediated replacement reactions which use the crystallography and elemental chemistry of the calcite. Experiments of fluid-mediated replacement reactions show that they proceed much faster than diffusion-based reactions. This is important when considering the rates of reactions relative to fluid flow in mineralising systems

Rethinking non-traditional resistance at work : the case of the Indian Diaspora in Mauritius

Resistance at work can take many forms and this is reflected in the multiple ways it has been theorised in research. In this paper, I use postcolonial theory to analyse employee resistance in Mauritius. To do this, I deploy Homi Bhabha’s concepts of mimicry, ambivalence and hybridity to explore non-traditional forms of resistance among the Indian Diaspora working in the hotel industry. Using ethnographic research, I firstly look at its ‘home’-making practices as it is within the home that visions of community emerge (Bhabha, 1994) which could later influence behaviours at work. I argue that the Diaspora maintains connections with its ancestral roots via routine religious practices and language use while concomitantly resisting assimilation in the local context. The analysis is then extended to their workplace where further forms of non-traditional resistance are found to be enacted which are strongly influenced by the same values emerging at home

HSPVdb—the Human Short Peptide Variation Database for improved mass spectrometry-based detection of polymorphic HLA-ligands

T cell epitopes derived from polymorphic proteins or from proteins encoded by alternative reading frames (ARFs) play an important role in (tumor) immunology. Identification of these peptides is successfully performed with mass spectrometry. In a mass spectrometry-based approach, the recorded tandem mass spectra are matched against hypothetical spectra generated from known protein sequence databases. Commonly used protein databases contain a minimal level of redundancy, and thus, are not suitable data sources for searching polymorphic T cell epitopes, either in normal or ARFs. At the same time, however, these databases contain much non-polymorphic sequence information, thereby complicating the matching of recorded and theoretical spectra, and increasing the potential for finding false positives. Therefore, we created a database with peptides from ARFs and peptide variation arising from single nucleotide polymorphisms (SNPs). It is based on the human mRNA sequences from the well-annotated reference sequence (RefSeq) database and associated variation information derived from the Single Nucleotide Polymorphism Database (dbSNP). In this process, we removed all non-polymorphic information. Investigation of the frequency of SNPs in the dbSNP revealed that many SNPs are non-polymorphic “SNPs”. Therefore, we removed those from our dedicated database, and this resulted in a comprehensive high quality database, which we coined the Human Short Peptide Variation Database (HSPVdb). The value of our HSPVdb is shown by identification of the majority of published polymorphic SNP- and/or ARF-derived epitopes from a mass spectrometry-based proteomics workflow, and by a large variety of polymorphic peptides identified as potential T cell epitopes in the HLA-ligandome presented by the Epstein–Barr virus cells