Flow Structure and Channel Stability at the Site of a Deep Scour Hole, Mackenzie Delta, Canada

Unusually deep scour holes in distributary channels of the Mackenzie Delta are of concern for oil and gas resource development, particularly with respect to buried pipeline crossings. Surveys of one such hole, carried out in 1985 and 1992, indicated vertical stability and slight lateral movement. The present study examines how the hole may have changed by the mid-2000s and documents the complex local velocity field and related bed material properties. Small discrepancies between isobaths of different years suggest a dynamic stability that involves short-term fluctuations in erosion and deposition. This suggestion was corroborated by detailed measurements of the highly three-dimensional velocity field, which revealed major eddy structures and flow reversals that help maintain sizeable velocity magnitudes despite low mean velocities. The composition of the bed material suggests cohesive behaviour, but the literature indicates a range of critical shear stresses that spans two orders of magnitude. The more probable lower end of this range is consistent with the observed dynamic stability of the scour hole.Des fosses d’affouillement exceptionnellement profondes se trouvant dans les effluents du delta du Mackenzie risquent de poser des problèmes en matière de mise en valeur des ressources pétrolières et gazières, surtout en ce qui a trait aux pipelines enfouis. Selon les levés d’une de ces fosses effectués en 1985 et en 1992, cette fosse serait verticalement stable et aurait un léger mouvement latéral. La présente étude se penche sur la façon dont la fosse pourrait avoir changé une fois rendu vers le milieu des années 2000 et documente le champ de vitesse local complexe de même que les propriétés des matériaux de fond connexes. De petits écarts entre les isobathes de différentes années laissent entrevoir une stabilité dynamique assortie de fluctuations à court terme sur le plan de l’érosion et de la déposition. Cette suggestion a été corroborée à l’aide de mesures détaillées du champ de vitesse hautement tridimensionnel, qui a révélé d’importantes structures à grands tourbillons et des écoulements de retour qui favorisent le maintien d’intensités de vitesse appréciables malgré des vélocités moyennes faibles. Bien que la composition des matériaux de fond suggère un comportement cohésif, la documentation indique une gamme de contraintes de cisaillement critique qui s’étend sur deux ordres de grandeur. Le bas de cette gamme plus probable est conforme à la stabilité dynamique observée à l’égard de la fosse d’affouillement

Developing an impact library for forecasting surface water flood risk

During surface water flooding events, emergency responders require detailed information on the risks posed in order to provide an appropriate and effective response. Few early warning systems quantitatively estimate the risk and impacts of surface water flooding. Improvements in computational processing capability, availability of new datasets and developments in forecasting models means that the forecasting information currently being supplied by the Flood Forecasting Centre can be improved upon through the application of a timely, impact‐based model. This article presents a novel approach to collating receptor datasets into a pre‐calculated Impact Library for use in a Hazard Impact Model (HIM) that will operate using real‐time probabilistic rainfall and surface runoff forecasts for England and Wales. The HIM provides an approach suitable for modelling flood impacts. Initial results are presented for a case study covering the 2012 floods in the North East of England. Information generated by the HIM provides additional benefits beyond current methods. Features include operator access to 1 km 15 min spatial–temporal data, analysis of individual impact criteria and modular refinement of the Impact Library to suit different situations. The HIM has been developed in partnership via the Natural Hazards Partnership

Transitions in modes of coastal adaptation: addressing blight, engagement and sustainability

Coastal defences have long provided protection from erosion and flooding to cities, towns and villages. In many parts of the world, continued defence is being questioned due to both environmental, sustainability and economic considerations. This is exemplified in England and Wales, where strategic Shoreline Management Plans envisage realignment of many protected coasts, often with low population densities, over the coming decades. The policy transition from protection to realignment is often resisted by affected communities and can have high political costs. Whilst some preparations for such transitions have been made, the communities affected are often not fully aware of the implications of policy change, and this brings the potential for blight. In this paper, we investigate the challenges of implementing transitions in coastal policy within England and Wales. The analysis is based on data obtained from three workshops held in 2019 that were attended by council members, engineers, planners, scientists and other relevant professionals. Five conditions are found to promote contention: (i) policy actors with competing priorities and different decision making time frames (immediate to decadal to a century); (ii) divergence between regulations and ad hoc political decisions (e.g. in relation to the demand for new housing); (iii) limited or non-existent funding to support policy transition; (iv) community expectation that protection is forever; and (v) a disconnection between people and ongoing coastal change. Our research indicates that transitions can be better supported through: (1) integrated multi-scalar preparedness for coastal change; (2) an accessible evidence base and future vision to nurture political confidence in adaptation; and (3) defined, time-bound and accessible diverse funding streams to achieve transitions. Critically, these generic actions need to be embedded within the local political and planning system to facilitate transition to more sustainable coasts and their communities

Antimalarial Therapy Selection for Quinolone Resistance among Escherichia coli in the Absence of Quinolone Exposure, in Tropical South America

BACKGROUND: Bacterial resistance to antibiotics is thought to develop only in the presence of antibiotic pressure. Here we show evidence to suggest that fluoroquinolone resistance in Escherichia coli has developed in the absence of fluoroquinolone use. METHODS: Over 4 years, outreach clinic attendees in one moderately remote and five very remote villages in rural Guyana were surveyed for the presence of rectal carriage of ciprofloxacin-resistant gram-negative bacilli (GNB). Drinking water was tested for the presence of resistant GNB by culture, and the presence of antibacterial agents and chloroquine by HPLC. The development of ciprofloxacin resistance in E. coli was examined after serial exposure to chloroquine. Patient and laboratory isolates of E. coli resistant to ciprofloxacin were assessed by PCR-sequencing for quinolone-resistance-determining-region (QRDR) mutations. RESULTS: In the very remote villages, 4.8% of patients carried ciprofloxacin-resistant E. coli with QRDR mutations despite no local availability of quinolones. However, there had been extensive local use of chloroquine, with higher prevalence of resistance seen in the villages shortly after a Plasmodium vivax epidemic (p<0.01). Antibacterial agents were not found in the drinking water, but chloroquine was demonstrated to be present. Chloroquine was found to inhibit the growth of E. coli in vitro. Replica plating demonstrated that 2-step QRDR mutations could be induced in E. coli in response to chloroquine. CONCLUSIONS: In these remote communities, the heavy use of chloroquine to treat malaria likely selected for ciprofloxacin resistance in E. coli. This may be an important public health problem in malarious areas

Direct Evidence for Packaging Signal-Mediated Assembly of Bacteriophage MS2

Using cross-linking coupled to matrix-assisted laser desorption/ionization mass spectrometry and CLIP-Seq sequencing, we determined the peptide and oligonucleotide sequences at the interfaces between the capsid proteins and the genomic RNA of bacteriophage MS2. The results suggest that the same coat protein (CP)-RNA and maturation protein (MP)-RNA interfaces are used in every viral particle. The portions of the viral RNA in contact with CP subunits span the genome, consistent with a large number of discrete and similar contacts within each particle. Many of these sites match previous predictions of the locations of multiple, dispersed and degenerate RNA sites with cognate CP affinity termed packaging signals (PSs). Chemical RNA footprinting was used to compare the secondary structures of protein-free genomic fragments and the RNA in the virion. Some PSs are partially present in protein-free RNA but others would need to refold from their dominant solution conformations to form the contacts identified in the virion. The RNA-binding peptides within the MP map to two sections of the N-terminal half of the protein. Comparison of MP sequences from related phages suggests a similar arrangement of RNA-binding sites, although these N-terminal regions have only limited sequence conservation. In contrast, the sequences of the C-termini are highly conserved, consistent with them encompassing pilin-binding domains required for initial contact with host cells. These results provide independent and unambiguous support for the assembly of MS2 virions via a PS-mediated mechanism involving a series of induced-fit viral protein interactions with RNA

A generalisable integrated natural capital methodology for targeting investment in coastal defence

This is the final version. Available on open access from Taylor & Francis via the DOI in this recordCoastal ecosystems, such as saltmarsh, produce a range of ecosystem services that underpin human well-being. In the UK, and globally, saltmarsh extent and quality is declining due to coastal squeeze, deteriorating water quality, and agricultural activities. Here, we develop a general framework to evaluate changes in coastal defence. Using this framework, we identify priority areas for saltmarsh re-alignment: re-creation of saltmarsh in areas that have been saltmarsh in the past – but that have been claimed for a variety of land uses, particularly agriculture. We base our re-alignment prioritisation on the ecosystem services provided by saltmarsh in the North Devon Biosphere Reserve: specifically carbon sequestration and recreational benefits, and the economic values of those services. We compare potential economic benefits with the economic costs of creating new saltmarsh areas – specifically lost agricultural output, property damages and direct re-alignment costs. We identify a number of priority areas for managed re-alignment that generate high recreational values in areas where properties would not be damaged. These findings provide a necessary and timely analysis for the managers of the North Devon Biosphere Reserve. Furthermore, we outline a comprehensive methodology to plan future management of coastal zones.This research formed part of the Valuing Nature Programme (valuing-nature.net) which is funded by the Natural Environment Research Council, the Economic and Social Research Council, the Biotechnology and Biological Sciences Research Council, the Arts and Humanities Research Council and the Department for Environment, Food and Rural Affairs

Exploring links between shyness, romantic relationship quality, and well-being

Romantic relationship quality. In the current study, we considered different components of romantic relationship quality, including specific aspects of current relationships, as well as more general romantic relationship attitudes and beliefs. For example, intimacy refers to the closeness and interdependence, affection and warmth, and the extent of self-disclosure within a romantic relationship (Perlman & Fehr, 1987). Sexual satisfaction represents the thoughts, feelings, personal/sociocultural attitudes, and biological variables that contribute to an individual\u27s positive sexual experiences (Penhollow & Young, 2008). Levels of intimacy and sexual satisfaction are both strong predictors of the success of romantic relationships, and are often used as indices of relationship quality (Burleson, Trevathan, & Todd, 2007; Penhollow & Young, 2008; Young, Denny, Luquis, & Young, 1998). Overall, romantic relationships characterized by higher quality tend to be associated with greater well-being (Birditt & Antonucci, 2007; Lanz & Tagliabue, 2007; Segrin, Powell, Givertz, & Brackin, 2003). Romantic relationship quality also appears to be influenced by individuals\u27 more general attitudes and beliefs regarding close relationships (Miller & Hoicowitz, 2004; Noftle & Shaver, 2005). For example, from an attachment perspective (Bowlby, 1973), internal working models are described as cognitive-affective representations that people form of the bond they have with their attachment figure and the expectations they have within close relationships. Variations related to attachment anxiety (i.e., anxiety about rejection, abandonment, and relational self-worth and acceptance) and attachment avoidance (avoidance of intimacy, discom- fort with closeness and interdependence) have been shown to contribute toward individual differences in feelings, thoughts, and behaviours among adults in close relationships (Bartholomew & Horowitz, 1991; [Collins] et al., 2006; Hazan & Shaver, 1987; Noftle & Shaver, 2006). As well, more positive romantic attachment beliefs also tend to promote psychological well-being (Collins et al., 2006; Noftle & Shaver, 2006). As described earlier, results from Study 1 indicated that young adults currently in romantic relationships reported lower levels of shyness than young adults not in a relationship ([Asendorpf] et al., 2008; [Leck], 2006). Our results further suggested that, even when they find romantic partners, shy individuals may be prone to experience poor relationship quality. Across both studies and across multiple indicators, shyness was robustly negatively related to a range of indices of romantic relationship quality. These results support previous research indicating that shyer individuals tend to form relationships less positive in quality (e.g., Koydemir & Demir, 2008; [Nelson] et al., 2008), and extend our knowledge by including multiple aspects of relationship quality (e.g., intimacy, sexual satisfaction, and romantic attachment beliefs). For example, because open communication and intimacy are important for sexual satisfaction (Byers & Demmons, 1999; Cupach & Comstock, 1990), and shyness is associated with difficulty communicating (especially about personal matters) and decreased responsiveness (Bradshaw, 2006; Koydemir & Demir, 2008; [Zimbardo], 1997), shyer individuals would seem more likely to report lower sexual satisfaction. Self-disclosure, warmth, and responsiveness are key components of intimacy (Kalliopuska, 2008), which may also help to account for its negative association with shyness