Analysis of Digital Media: Supporting University-Wide Online Learning via Moodle

This report aims to provide an overview of a project which explores teaching and learning within a blended mode of study. Specifically, it looks to analyse the production of digital media and online social networking with a view to enhancing the learning experience. It was the overall aim of the project to contribute to the University’s Learning and Teaching Strategy by developing media content; exploring the production process, analyse digital participation and explore the challenges and opportunities locally within schools. The project has placed emphasis on the production principles which enhance our online courses whilst providing a consistent quality of experience – recognising that our students often access course material produced by staff from across schools and colleges

Analysis of Digital Media: Supporting University-Wide Online Learning via Moodle

This report aims to provide an overview of a project which explores teaching and learning within a blended mode of study. Specifically, it looks to analyse the production of digital media and online social networking with a view to enhancing the learning experience. It was the overall aim of the project to contribute to the University’s Learning and Teaching Strategy by developing media content; exploring the production process, analyse digital participation and explore the challenges and opportunities locally within schools. The project has placed emphasis on the production principles which enhance our online courses whilst providing a consistent quality of experience – recognising that our students often access course material produced by staff from across schools and colleges

Photophysics and Dihedral Freedom of the Chromophore in Yellow, Blue, and Green Fluorescent Protein

Green fluorescent protein (GFP) and GFP-like fluorescent proteins owe their photophysical properties to an autocatalytically formed intrinsic chromophore. According to quantum mechanical calculations, the excited state of chromophore model systems has significant dihedral freedom, which may lead to fluorescence quenching intersystem crossing. Molecular dynamics simulations with freely rotating chromophoric dihedrals were performed on green, yellow, and blue fluorescent proteins in order to model the dihedral freedom available to the chromophore in the excited state. Most current theories suggest that a restriction in the rotational freedom of the fluorescent protein chromophore will lead to an increase in fluorescence brightness and/or quantum yield. According to our calculations, the dihedral freedom of the systems studied (BFP > A5 > YFP > GFP) increases in the inverse order to the quantum yield. In all simulations, the chromophore undergoes a negatively correlated hula twist (also known as a bottom hula twist mechanism)

The Role of the Tight-Turn, Broken Hydrogen Bonding, Glu222 and Arg96 in the Post-translational Green Fluorescent Protein Chromophore Formation

Green fluorescent proteins (GFP) and GFP-like proteins all undergo an autocatalytic post-translational modification to form a centrally located chromophore. Structural analyses of all the GFP and GFP-like proteins in the protein databank were undertaken to determine the role of the tight-turn, broken hydrogen bonding, Gly67, Glu222 and Arg96 in the biosynthesis of the imidazolone group from 65SYG67. The analysis was supplemented by computational generation of the conformation adopted by uncyclized wild-type GFP. The data analysis suggests that Arg96 interacts with the Tyr66 carbonyl, stabilizing the reduced enolate intermediate that is required for cyclization; the carboxylate of Glu222 acts as a base facilitating, through a network of two waters, the abstraction of a hydrogen from the α-carbon of Tyr66; a tight-turn conformation is required for autocatalytic cyclization. This conformation is responsible for a partial reduction in the hydrogen bonding network around the chromophore-forming region of the immature protein

Evidence for weathering and volcanism during the PETM from Arctic Ocean and Peri-Tethys osmium isotope records

Sudden global warming during the Paleocene–Eocene Thermal Maximum (PETM, 55.9 Ma) occurred because of the rapid release of several thousand gigatonnes of isotopically light carbon into the oceans and atmosphere; however, the cause of this release is not well understood. Some studies have linked carbon injection to volcanic activity associated with the North Atlantic Igneous Province (NAIP), while others have emphasised carbon cycle feedbacks associated with orbital forcing. This study presents the osmium isotope compositions of mudrocks that were deposited during the PETM at four locations (one from the Arctic Ocean, and three from the Peri-Tethys). The Os-isotope records all exhibit a shift of similar magnitude towards relatively radiogenic values across the PETM. This observation confirms that there was a transient, global increase in the flux of radiogenic Os from the weathering of continental rocks in response to elevated temperatures at that time. The tectonic effects of NAIP volcanic emplacement near the onset of the PETM is recorded by anomalously radiogenic Os-isotope compositions of PETM-age Arctic Ocean samples, which indicate an interval of hydrographic restriction that can be linked tectonic uplift due to hotspot volcanism in the North Atlantic seaway. The Peri-Tethys data also document a transient, higher flux of unradiogenic osmium into the ocean near the beginning of the PETM, most likely from the weathering of young mafic rocks associated with the NAIP. These observations support the hypothesis that volcanism played a major role in triggering the cascade of environmental changes during the PETM, and highlight the influence of paleogeography on the Os isotope characteristics of marine water masses

A Graph Aided Strategy to Produce Good Recursive Towers over Finite Fields

International audienceWe propose a systematic method to produce potentially good recursive towers over finite fields. The graph point of view, so as some magma and sage computations are used in this process.We also establish some theoretical functional criterion ensuring the existence of many rational points on a recursive tower. Both points are illustrated by an example, from the production process, to the theoretical study

Isotopic constraints on ocean redox at the end of the Eocene

A multi-million-year decrease in global temperatures during the Eocene was accompanied by large reorganisations to ocean circulation, ocean chemistry and biological productivity. These changes culminated in the rapid growth of grounded ice on Antarctica during the Eocene–Oligocene climate transition (EOT), ∼34 million years ago. However, while it is likely that environmental perturbations of this magnitude altered the oceanic oxygen inventory, the sign and magnitude of the response is poorly constrained. We show that euxinic, hydrographically restricted conditions developed in the Austrian Molasse Basin during the EOT. The isotopic compositions of molybdenum and uranium captured by sediments accumulating in the Molasse Basin at this time reveal that the global extent of sulfidic conditions during the EOT was not appreciably different to that of the Early Eocene greenhouse world. Our results suggest that the early Cenozoic oceans were buffered against extreme long-term changes in oxygenation