Southern North Sea storm surge event of 5 December 2013: Water levels, waves and coastal impacts

The storm surge event that affected the coastal margins of the southern North Sea on 5–6 December 2013 produced the highest still water levels on record at several tide gauges on the UK east coast. On east-facing coasts south of the Humber estuary and north-facing Norfolk, water levels were higher than in the twentieth century benchmark surge event of 31 January–1 February 1953. Maximum significant wave heights were highest off the North Norfolk coast (peak Hs = 3.8 m offshore, 2.9 m inshore) and lowest off the Suffolk coast (Hs = 1.5–1.8 m inshore); comparable offshore wave heights in 1953 were 7–8 m and ca. 3 m. The lower wave heights, and their short duration, in 2013 explain both localised breaching, overtopping, and back-barrier flooding associated with gravel ridges and relatively low earthen banks as well as the lack of failure in more highly-engineered coastal defences. On barrier coasts and within estuaries, the signal of maximum runup was highly variable, reflecting the modification of the tide–surge–wave signal by inshore bathymetry and the presence of a range of coastal ecosystems. The landscape impacts of the December 2013 surge included the notching of soft rock cliffs and cliffline retreat; erosion of coastal dunes; and the augmentation or re-activation of barrier island washover deposits. Whilst surge event-related cliff retreat on the rapidly eroding cliffs of the Suffolk coast lay within the natural variability in inter-annual rates of retreat, the impact of the surge on upper beach/sand dune margins produced a pulse of shoreline translation landwards equivalent to about 10 years of ‘normal’ shoreline retreat. The study of east coast surges over the last 60 years, and the identification of significant phases of landscape change — such as periods of rapid soft rock cliff retreat and the formation of new gravel washovers on barrier islands — points to the importance of high water levels being accompanied by high wave activity. Future developments in early warning systems and evacuation planning require information on the variable impacts of such extreme events.This paper is a contribution to NERC BESS Consortium grant A hierarchical approach to the examination of the relationship between biodiversity and ecosystem service flows across coastal margins (grant reference NE/J015423/1). Table 5 incorporates information gathered as part of an EU FP7 Collaborative Project Resilience-Increasing Strategies for Coasts — toolkit (RISC_KIT).This is the final published version. It first appeared at http://www.sciencedirect.com/science/article/pii/S0012825215000628#

The impact of pre-restoration land-use and disturbance on sediment structure, hydrology and the sediment geochemical environment in restored saltmarshes

Saltmarshes are being lost or degraded as a result of human activity resulting in loss of critical ecosystem services including the provision of wild species diversity, water quality regulation and flood regulation. To compensate, saltmarshes are being restored or re-created, usually driven by legislative requirements for increased habitat diversity, flood regulation and sustainable coastal defense. Yet, there is increasing evidence that restoration may not deliver anticipated ecosystem services; this is frequently attributed to poor drainage and sediment anoxia. However, physical sediment characteristics, hydrology and the sediment geochemical environment are rarely examined in restoration schemes, despite such factors being critical for plant succession. This study presents the novel integration of 3D-computed X-ray microtomography to quantify sediment structure and porosity, with water level and geochemical data to understand the impact of pre-restoration land use and disturbance on the structure and functioning of restored saltmarshes. The study combines a broad-scale investigation of physical sediment characteristics in nine de-embanked saltmarshes across SE England, with an intensive study at one site examining water levels, sediment structure and the sediment geochemical environment. De-embankment does not restore the hydrological regime, or the physical/chemical framework in the saltmarshes and evidence of disturbance includes a reduction in microporosity, pore connectivity and water storage capacity, a lack of connectivity between the sub-surface environment and overlying floodwaters, and impeded sub-surface water flow and drainage. This has significant consequences for the sediment geochemical environment. This disturbance is evident for at least two decades following restoration and is likely to be irreversible. It has important implications for plant establishment in particular, ecosystem services including flood regulation, nutrient cycling and wild species diversity and for future restoration design

Expression and Distribution of Ectonucleotidases in Mouse Urinary Bladder

Background: Normal urinary bladder function requires bidirectional molecular communication between urothelium, detrusor smooth muscle and sensory neurons and one of the key mediators involved in this intercellular signaling is ATP. Ectonucleotidases dephosphorylate nucleotides and thus regulate ligand exposure to P2X and P2Y purinergic receptors. Little is known about the role of these enzymes in mammalian bladder despite substantial literature linking bladder diseases to aberrant purinergic signaling. We therefore examined the expression and distribution of ectonucleotidases in the mouse bladder since mice offer the advantage of straightforward genetic modification for future studies. Principal Findings: RT-PCR demonstrated that eight members of the ectonucleoside triphosphate diphosphohydrolase (NTPD) family, as well as 5'-nucleotidase (NT5E) are expressed in mouse bladder. NTPD1, NTPD2, NTPD3, NTPD8 and NT5E all catalyze extracellular nucleotide dephosphorylation and in concert achieve stepwise conversion of extracellular ATP to adenosine. Immunofluorescent localization with confocal microscopy revealed NTPD1 in endothelium of blood vessels in the lamina propria and in detrusor smooth muscle cells, while NTPD2 was expressed in cells localized to a region of the lamina propria adjacent to detrusor and surrounding muscle bundles in the detrusor. NTPD3 was urothelial-specific, occurring on membranes of intermediate and basal epithelial cells but did not appear to be present in umbrella cells. Immunoblotting confirmed NTPD8 protein in bladder and immunofluorescence suggested a primary localization to the urothelium. NT5E was present exclusively in detrusor smooth muscle in a pattern complementary with that of NTPD1 suggesting a mechanism for providing adenosine to P1 receptors on the surface of myocytes. Conclusions: Ectonucleotidases exhibit highly cell-specific expression patterns in bladder and therefore likely act in a coordinated manner to regulate ligand availability to purinergic receptors. This is the first study to determine the expression and location of ectonucleotidases within the mammalian urinary bladder

Mechanism of Disruption of the Amt-GlnK Complex by PII-Mediated Sensing of 2-Oxoglutarate

GlnK proteins regulate the active uptake of ammonium by Amt transport proteins by inserting their regulatory T-loops into the transport channels of the Amt trimer and physically blocking substrate passage. They sense the cellular nitrogen status through 2-oxoglutarate, and the energy level of the cell by binding both ATP and ADP with different affinities. The hyperthermophilic euryarchaeon Archaeoglobus fulgidus possesses three Amt proteins, each encoded in an operon with a GlnK ortholog. One of these proteins, GlnK2 was recently found to be incapable of binding 2-OG, and in order to understand the implications of this finding we conducted a detailed structural and functional analysis of a second GlnK protein from A. fulgidus, GlnK3. Contrary to Af-GlnK2 this protein was able to bind both ATP/2-OG and ADP to yield inactive and functional states, respectively. Due to the thermostable nature of the protein we could observe the exact positioning of the notoriously flexible T-loops and explain the binding behavior of GlnK proteins to their interaction partner, the Amt proteins. A thermodynamic analysis of these binding events using microcalorimetry evaluated by microstate modeling revealed significant differences in binding cooperativity compared to other characterized PII proteins, underlining the diversity and adaptability of this class of regulatory signaling proteins

There is no such thing as ‘undisturbed’ soil and sediment sampling: sampler-induced deformation of salt marsh sediments revealed by 3D X-ray computed tomography

Purpose: Within most environmental contexts, the collection of 'undisturbed' samples is widely relied-upon in studies of soil and sediment properties and structure. However, the impact of sampler-induced disturbance is rarely acknowledged, despite the potential significance of modification to sediment structure for the robustness of data interpretation. In this study, 3D-computed X-ray microtomography (μCT) is used to evaluate and compare the disturbance imparted by four commonly-used sediment sampling methods within a coastal salt-marsh. Materials and methods: Paired sediment core samples from a restored salt-marsh at Orplands Farm, Essex, UK were collected using four common sampling methods (push, cut, hammer and gouge methods). Sampling using two different area-ratio cores resulted in a total of 16 cores that were scanned using 3D X-Ray computed tomography, to identify and evaluate sediment structural properties of samples that can be attributed to sampling method. Results and discussion: 3D qualitative analysis identifies a suite of sampling-disturbance structures including gross-scale changes to sediment integrity and substantial modification of pore-space, structure and distribution, independent of sediment strength and stiffness. Quantitative assessment of changes to pore-space and sediment density arising from the four sampling methods offer a means of direct comparison between the impact of depth-sampling methods. Considerable disturbance to samples result from use of push, hammer and auguring samplers, whilst least disturbance is found in samples recovered by cutting and advanced trimming approaches. Conclusions: It is evident that with the small-bore tubes and samplers commonly used in environmental studies, all techniques result in disturbance to sediment structure to a far greater extent than previously reported, revealed by μCT. This work identifies and evaluates for the first time the full nature, extent and significance of internal sediment disturbance arising from common sampling methods

Theory for the FCC-ee : Report on the 11th FCC-ee Workshop

The Future Circular Collider (FCC) at CERN, a proposed 100-km circular facility with several colliders in succession, culminates with a 100 TeV proton-proton collider. It offers a vast new domain of exploration in particle physics, with orders of magnitude advances in terms of Precision, Sensitivity and Energy. The implementation plan foresees, as a first step, an Electroweak Factory electron-positron collider. This high luminosity facility, operating between 90 and 365 GeV centre-of-mass energy, will study the heavy particles of the Standard Model, Z, W, Higgs, and top with unprecedented accuracy. The Electroweak Factory $e^+e^-$ collider constitutes a real challenge to the theory and to precision calculations, triggering the need for the development of new mathematical methods and software tools. A first workshop in 2018 had focused on the first FCC-ee stage, the Tera-Z, and confronted the theoretical status of precision Standard Model calculations on the Z-boson resonance to the experimental demands. The second workshop in January 2019, which is reported here, extended the scope to the next stages, with the production of W-bosons (FCC-ee-W), the Higgs boson (FCC-ee-H) and top quarks (FCC-ee-tt). In particular, the theoretical precision in the determination of the crucial input parameters, alpha_QED, alpha_QCD, M_W, m_t at the level of FCC-ee requirements is thoroughly discussed. The requirements on Standard Model theory calculations were spelled out, so as to meet the demanding accuracy of the FCC-ee experimental potential. The discussion of innovative methods and tools for multi-loop calculations was deepened. Furthermore, phenomenological analyses beyond the Standard Model were discussed, in particular the effective theory approaches. The reports of 2018 and 2019 serve as white papers of the workshop results and subsequent developments