An Evaluation of the Effects of Marine Oil-spills, Remediation Strategies, and Shipwrecks on Microbial Community Structure and Succession

The evaluation of how Bacteria respond to oil-contamination, and the application of dispersants and biosurfactants, in North Sea seawater microcosms is the focus of Chapter Two. Analysis revealed that dispersants and biosurfactants, which significantly reduced the interfacial tension between oil and water, significantly increased growth of obligate hydrocarbonoclastic bacteria (OHCB) in 24 hours, translating into significantly enhanced alkane-biodegradation. Early sampling of microcosms revealed how the OHCB Oleispira, hitherto considered a psychrophile, can dominate bacterial communities at the relatively high temperature of 16ºC. Bacterial response to oil-pollution is examined further in Chapter Three, where an in situ oil-slick is compared to a chemically dispersed oil-slick in the North Sea. Results suggest a lack of hydrocarbon-degrading bacteria (HCB) growth, even in samples with measurable hydrocarbons, could potentially be attributed to phosphorous limitation. Whilst the Ecological Index of Hydrocarbon Exposure, which quantifies the proportion of a bacterial community with hydrocarbon-biodegradation potential, revealed an extremely low score, highlighting a limited capacity for the environment, at the time of sampling, to naturally attenuate oil. Analysis of sediments contaminated by the Agia Zoni II oil-spill (Greece, 2017), in Chapter Four, demonstrated significant growth of HCB five-days post-oil-spill. Whilst the relative abundance of HCB declined as oil was removed, a legacy effect was observed, with the OHCB Alcanivorax and Cycloclasticus persisting for several months after the oil-spill. Finally, analysis of sediments around a North Sea shipwreck (HMS Royal Oak), in Chapter Five, revealed low levels of pyrogenic polycyclic aromatic hydrocarbons and little evidence of HCB, indicating sediments showed no long-term impact by previous oil-pollution from the shipwreck. This thesis not only advances our understanding of microbial response to oil-spills, remediation strategies, and shipwrecks, in a range of marine environments, but also highlights the importance of harnessing such knowledge and data to advance post-incident monitoring guidelines and models

Instabilities and Solitons in Minimal Strips.

We show that highly twisted minimal strips can undergo a nonsingular transition, unlike the singular transitions seen in the Möbius strip and the catenoid. If the strip is nonorientable, this transition is topologically frustrated, and the resulting surface contains a helicoidal defect. Through a controlled analytic approximation, the system can be mapped onto a scalar ϕ^{4} theory on a nonorientable line bundle over the circle, where the defect becomes a topologically protected kink soliton or domain wall, thus establishing their existence in minimal surfaces. Demonstrations with soap films confirm these results and show how the position of the defect can be controlled through boundary deformation.This work was supported in part by the UK EPSRC through Grant No. A.MACX.0002 (TM and GPA) and an EPSRC Established Career Fellowship (R. E. G. and A. I. P.). TM also supported by a University of Warwick Chancellor’s International Scholarship and by a University of Warwick IAS Early Career Fellowship.This is the final version of the article. It first appeared from the American Physical Society via http://dx.doi.org/10.1103/PhysRevLett.117.01780

Lateral stress evolution in chromium sulfide cermets with varying excess chromium

The shock response of chromium sulfide-chromium, a cermet of potential interest as a matrix material for ballistic applications, has been investigated at two molar ratios. Using a combustion synthesis technique allowed for control of the molar ratio of the material, which was investigated under near-stoichiometric (cermet) and excess chromium (interpenetrating composite) conditions, representing chromium:sulfur molar ratios of 1.15:1 and 4:1, respectively. The compacts were investigated via the plate-impact technique, which allowed the material to be loaded under a onedimensional state of strain. Embedded manganin stress gauges were employed to monitor the temporal evolution of longitudinal and lateral components of stress in both materials. Comparison of these two components has allowed assessment of the variation of material shear strength both with impact pressure/strain-rate and time for the two molar ratio conditions. The two materials exhibited identical material strength despite variations in their excess chromium content

Exploring and evaluating the two-factor model of perfectionism in sport

Perfectionism is a multidimensional personality trait with two higher-order dimensions; perfectionistic strivings and perfectionistic concerns. The purpose of the present study was to explore and evaluate the two-factor model for the first time using three instruments developed to measure perfectionism in sport. In doing so, we (i) assessed the fit of two-factor models when including and excluding various contentious subscales (other-oriented perfectionism, parental pressure, coach pressure, organisation, and negative reactions to imperfection) and (ii) compared two-factor models to alternative one-factor (or unidimensional) models. Participants were recruited from community and university sports clubs in the UK (N = 527; M age = 18.07 years, SD = 0.49) and completed the Sport-Multidimensional Perfectionism Scale-2, the Multidimensional Inventory of Perfectionism in Sport, and the Performance Perfectionism Scale-Sport. Support was found for the two-factor model, with superior fit displayed each time the aforementioned subscales were excluded and, in all cases, when compared to a unidimensional model. The findings suggest that the two-factor model is an adequate representation of the underlying structure of instruments designed to measure perfectionism in sport with better fit and conceptual clarity offered by more parsimonious models

Rushes video summarization using a collaborative approach

This paper describes the video summarization system developed by the partners of the K-Space European Network of Excellence for the TRECVID 2008 BBC rushes summarization evaluation. We propose an original method based on individual content segmentation and selection tools in a collaborative system. Our system is organized in several steps. First, we segment the video, secondly we identify relevant and redundant segments, and finally, we select a subset of segments to concatenate and build the final summary with video acceleration incorporated. We analyze the performance of our system through the TRECVID evaluation

Changes in gene expression patterns in the tumor microenvironment of head and neck squamous cell carcinoma under chemoradiotherapy depend on response

Chemoradiotherapy (CRT) is a standard treatment for advanced head and neck squamous cell carcinoma (HNSCC). Unfortunately, not all patients respond to this therapy and require further treatment, either salvage surgery or palliative therapy. The addition of immunotherapy to CRT is currently being investigated and early results describe a mixed response. Therefore, it is important to understand the impact of CRT on the tumor microenvironment (TME) to be able to interpret the results of the clinical trials. Paired biopsies from 30 HNSCC patients were collected before and three months after completion of primary CRT and interrogated for the expression of 1392 immune- and cancer-related genes. There was a relevant difference in the number of differentially expressed genes between the total cohort and patients with residual disease. Genes involved in T cell activation showed significantly reduced expression in these tumors after therapy. Furthermore, gene enrichment for several T cell subsets confirmed this observation. The analysis of tissue resident memory T cells (TRM) did not show a clear association with impaired response to therapy. CRT seems to lead to a loss of T cells in patients with incomplete response that needs to be reversed. It is not clear whether the addition of anti-PD-1 antibodies alone to CRT can prevent treatment failure, as no upregulation of the targets was measurable in the TME

Dynamics and Deposition of Sediment-Bearing Multi- Pulsed Flows and Geological Implication

Copyright © 2019, SEPM (Society for Sedimentary Geology) Previous studies on dilute, multi-pulsed, subaqueous saline flows have demonstrated that pulses will inevitably advect forwards to merge with the flow front. On the assumption that pulse merging occurs in natural-scale turbidity currents, it was suggested that multi-pulsed turbidites that display vertical cycles of coarsening and fining would transition laterally to single-pulsed, normally graded turbidites beyond the point of pulse merging. In this study, experiments of dilute, single- and multi-pulsed sediment-bearing flows (turbidity currents) are conducted to test the linkages between downstream flow evolution and associated deposit structure. Experimental data confirm that pulse merging occurs in laboratory-scale turbidity currents. However, only a weak correspondence was seen between longitudinal variations in the internal flow dynamics and the vertical structure of deposits; multi-pulsed deposits were documented, but transitioned to single-pulsed deposits before the pulse merging point. This early transition is attributed to rapid sedimentation-related depletion of the coarser-grained suspended fraction in the laboratory setting, whose absence may have prevented the distal development of multi-pulsed deposits; this factor complicates estimation of the transition point in natural-scale turbidite systems