Efficient modelling of thin conducting sheets within the TLM method

The paper describes the use of recursive filters to efficiently model the transmission through thin conducting layers in the Transmission Line Matrix (TLM) method of numerical electromagnetic modelling. The technique is applicable where the layer may be many skin-depths thick but thin compared with the mesh size. The technique is validated against an analytical solution, and improved efficiency over other methods is demonstrated. The technique is also applicable to composite layers with complex structures which are not amenable to analytical solution

Social and gender analysis report: Barotse Floodplain, Western Province,Zambia

There is increasing awareness that integrating gender into development frameworks is critical for effective implementation of development strategies. In working to alleviate rural poverty, the CGIAR Research Program on Aquatic Agricultural Systems (AAS) recognizes that “business as usual” gender integration approaches will not deliver lasting and widespread improvements in agricultural productivity, poverty reduction and food security. In response, AAS operationalized a gender transformative approach. The approach is informed by conceptual frameworks that explicitly recognize the potent influence of social relations on creating and perpetuating gender inequalities. In this way, AAS aims to address the underlying causes of rural poverty and gender inequality in Zambia’s Barotse Floodplain, where people rely extensively on riverine and wetland ecosystems for food and livelihood security. A central question guiding the research program is “How do social norms and gendered power relations influence agricultural development outcomes?” The findings presented in this report provide insights that help answer this question. The report presents a review of literature relevant to livelihoods, ecosystem services, and gender and social relations in Zambia, with a specific focus on Western Province, where AAS is currently implemented. It also presents a synthesis of findings of a social and gender analysis conducted in 2013 in 10 focal communities situated in and around the Barotse Floodplain

Surface water flood forecasting for urban communities

Key findings and recommendations: • This research has addressed the challenge of surface water flood forecasting by producing the UK’s first operational surface water flood risk forecast with a 24-hour lead time. This was successfully used in Glasgow at the Commonwealth Games in 2014. • The methodology of the Glasgow Pilot has been developed to use nationally available datasets and a transferrable approach which will help urban areas in Scotland improve their resilience to and preparedness for future flooding. • It also delivered a novel method for forecasting the impacts of flooding in real-time and increased knowledge on communicating uncertainties in flood risk. • A real-time forecasting system for surface water flooding from intense rainfall needs to use models that represent surface runoff production, surface water inundation and movement, and how water travels via surface and sub-surface pathways, including urban sewerage and drainage networks. Ensemble rainfall prediction models are key to quantifying uncertainty in forecasting the rainfall that causes surface water flooding. • Detailed surface water flood inundation models exist and are widely used in design and research activities, but none were found to be ready for real-time use. The Grid-to-Grid (G2G) distributed hydrological model was chosen for used in the Glasgow Pilot as it can provide ensemble forecasts of surface water flooding, and takes account of the intensity and pattern of rainfall, land cover and slope, and antecedent conditions. • The research developed a novel methodology for impact assessment that links surface runoff to the severity of flooding impacts on people, property and transport. Use is made of a library of information based on SEPA’s Regional Pluvial (rainfall-related) Flood Hazard maps. • For the Glasgow Pilot, G2G was operated over a 10km by 10km area encompassing Glasgow’s East End and the main areas of activity for the 2014 Commonwealth Games. The research team developed an operational application, called FEWS Glasgow, to support running the model in real-time and reporting on the likely impacts of surface water flooding. A new Daily Glasgow Daily Surface Water Flood Forecast was designed and produced based on operational requirements and emergency responder feedback

CEH-GEAR: 1 km resolution daily and monthly areal rainfall estimates for the UK for hydrological and other applications

The Centre for Ecology & Hydrology – Gridded Estimates of Areal Rainfall (CEH-GEAR) data set was developed to provide reliable 1 km gridded estimates of daily and monthly rainfall for Great Britain (GB) and Northern Ireland (NI) (together with approximately 3500 km2 of catchment in the Republic of Ireland) from 1890 onwards. The data set was primarily required to support hydrological modelling. The rainfall estimates are derived from the Met Office collated historical weather observations for the UK which include a national database of rain gauge observations. The natural neighbour interpolation methodology, including a normalisation step based on average annual rainfall (AAR), was used to generate the daily and monthly rainfall grids. To derive the monthly estimates, rainfall totals from monthly and daily (when complete month available) rain gauges were used in order to obtain maximum information from the rain gauge network. The daily grids were adjusted so that the monthly grids are fully consistent with the daily grids. The CEH-GEAR data set was developed according to the guidance provided by the British Standards Institution. The CEH-GEAR data set contains 1 km grids of daily and monthly rainfall estimates for GB and NI for the period 1890–2012. For each day and month, CEH-GEAR includes a secondary grid of distance to the nearest operational rain gauge. This may be used as an indicator of the quality of the estimates. When this distance is greater than 100 km, the estimates are not calculated due to high uncertainty

Regulation, sensory domains and roles of two Desulfovibrio desulfuricans ATCC27774 Crp family transcription factors, HcpR1 and HcpR2, in response to nitrosative stress

In silico analyses identified a Crp/Fnr family transcription factor (HcpR) in sulfate-reducing bacteria that controls expression of the hcp gene, which encodes the hybrid cluster protein and contributes to nitrosative stress responses. There is only one hcpR gene in the model sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough, but two copies in D. desulfuricans 27774, which can use nitrate as an alternative electron acceptor to sulfate. Structures of the D. desulfuricans hcpR1, hcpR2 and hcp operons are reported. We present evidence that hcp expression is regulated by HcpR2, not by HcpR1, and that these two regulators differ in both their DNA-binding site specificity and their sensory domains. HcpR1 is predicted to be a b-type cytochrome. HcpR1 binds upstream of the hcpR1 operon and its synthesis is regulated coordinately with hcp in response to NO. In contrast, hcpR2 expression was not induced by nitrate, nitrite or NO. HcpR2 is an iron-sulfur protein that reacts with NO and O2 . We propose that HcpR1 and HcpR2 use different sensory mechanisms to regulate subsets of genes required for defense against NO-induced nitrosative stress, and that diversification of signal perception and DNA recognition by these two proteins is a product of D. desulfuricans adaptation to its particular environmental niche. This article is protected by copyright. All rights reserved

Galactic cannibalism in the galaxy cluster C0337-2522 at z=0.59

According to the galactic cannibalism model, cD galaxies are formed in the center of galaxy clusters by merging of massive galaxies and accretion of smaller stellar systems: however, observational examples of the initial phases of this process are lacking. We have identified a strong candidate for this early stage of cD galaxy formation: a group of five elliptical galaxies in the core of the X-ray cluster C0337-2522 at redshift z=0.59. With the aid of numerical simulations, in which the galaxies are represented by N-body systems, we study their dynamical evolution up to z=0; the cluster dark matter distribution is also described as a N-body system. We find that a multiple merging event in the considered group of galaxies will take place before z=0 and that the merger remnant preserves the Fundamental Plane and the Faber-Jackson relations, while its behavior with respect to the Mbh-sigma relation is quite sensitive to the details of black hole merging [abridged].Comment: 30 pages, 7 figures, MNRAS (accepted

Does early intervention improve outcomes in the physiotherapy management of lumbar radicular syndrome? Results of the POLAR pilot randomised controlled trial

OBJECTIVE: To investigate the feasibility of undertaking a definitive randomised controlled trial (RCT). SETTING: This was a pilot, pragmatic superiority RCT with a qualitative element, recruiting from 14 general practitioner (GP) practices in England. PARTICIPANTS: Patients over 18 years of age presenting to their GP with unilateral lumbar radicular syndrome (LRS), defined as radicular pain and/or neurological symptoms originating from lumbar nerve roots, were eligible to participate in the study, those who did not have a clear understanding of the English language or had comorbidities preventing rehabilitation were ineligible. INTERVENTIONS: Participants were randomised into early intervention physiotherapy or usual care with the former receiving their treatment within 2 weeks after randomisation and the latter 6 weeks postrandomisation. Both groups received a patient-centred, goal-orientated physiotherapy programme specific to their needs. Participants received up to six treatment sessions over an 8-week period. OUTCOME MEASURES: Process outcomes to determine the feasibility of the study and an exploratory analysis of patient-reported outcomes, including self-rated disability, pain and general health, these were collected at baseline, 6, 12 and 26 weeks postrandomisation. RESULTS: 80 participants were recruited in 10 GP practices over 34 weeks and randomised to (early intervention physiotherapy n=42, usual care n=38). Follow-up rates at 26 weeks were 32 (84%) in the usual care and 36 (86%) in the early intervention physiotherapy group. The mean area under the curve (larger values indicating more disability) for the Oswestry Disability Index over the 26 weeks was 16.6 (SD 11.4) in the usual care group and 16.0 (SD 14.0) in the intervention group. A difference of -0.6 (95% CI -0.68 to 5.6) in favour of the intervention group. CONCLUSIONS: The results of the study suggest a full RCT is feasible and will provide evidence as to the optimal timing of physiotherapy for patients with LRS. TRIAL REGISTRATION NUMBER: NCT02618278, ISRCTN25018352

The role of macrophages in Staphylococcus aureus infection

Staphylococcus aureus is a member of the human commensal microflora that exists, apparently benignly, at multiple sites on the host. However, as an opportunist pathogen it can also cause a range of serious diseases. This requires an ability to circumvent the innate immune system to establish an infection. Professional phagocytes, primarily macrophages and neutrophils, are key innate immune cells which interact with S. aureus, acting as gatekeepers to contain and resolve infection. Recent studies have highlighted the important roles of macrophages during S. aureus infections, using a wide array of killing mechanisms. In defense, S. aureus has evolved multiple strategies to survive within, manipulate and escape from macrophages, allowing them to not only subvert but also exploit this key element of our immune system. Macrophage-S. aureus interactions are multifaceted and have direct roles in infection outcome. In depth understanding of these host-pathogen interactions may be useful for future therapeutic developments. This review examines macrophage interactions with S. aureus throughout all stages of infection, with special emphasis on mechanisms that determine infection outcome

Evaluating G2G for use in Rapid Response Catchments: Final Report

Flood impacts can be severe for rapid response catchments (RRCs). Providing targeted flood warnings is challenging using existing methodologies and on account of the typical absence of river flow gauging. The Pitt Review of the Summer 2007 floods recognised the need for new alert procedures for RRCs able to exploit the new distributed flood forecasting capability being progressed from research into operations. Work on the G2G (Grid-to-Grid) distributed hydrological model was accelerated into operational practice to support 5-day countrywide flood outlooks, a major recommendation of the Pitt Review. The present study aims to explore the potential of G2G to support more frequent and detailed alerts relevant to flood warning in RRCs. Integral to this study is the use of emerging rainfall forecast products, in deterministic and ensemble form, which allow the lead-time of G2G flow forecasts to be extended and given an uncertainty context. This Report sets down the overall scope of the project, provides an introduction to G2G by way of background and then reports on the outcomes of the R&D study. This includes extensive preparatory work on collating historical datasets to support G2G model assessment, both relating to hydrometry and new rainfall forecast products. A framework is developed for assessing G2G in both simulation-mode and forecast-mode (as a function of lead-time) targeted at the RRC requirement. Relevant to the requirement is the RRC Register of points and areas of interest compiled by the Environment Agency, and the characteristics of RRCs (occurring in isolation or in combination): small catchment area, urban/sub-urban land-cover and steep slopes. The assessment framework is first applied assuming perfect knowledge of rainfall observations for past and future times, so as not to confound the analysis with errors from rainfall forecasts. Variability of performance measures across groups of sites is summarised through box and whisker plots, groups being differentiated on size of catchment area and nature of G2G run (simulation, and with the addition of state updating and flow insertion in turn). Skill scores judge how well the model performs in detecting a flood event exceeding a flow threshold, taken as the median annual flood (as an indicator of bankfull flow exceedance for natural channels) and fractional multipliers of it. The skill scores include POD (Probability of Detection) and FAR (False Alarm Ratio). Performance maps of R2 Efficiency, indicating the variability in the observations accounted for by the model, are used to portray the spatial variability of G2G accuracy across the country. G2G performance in small catchments, relevant to the RRC requirement, is best over South West, North East and North West regions; also median performance appears robust from one year to the next. Larger catchments benefit most in forecast-mode from flow insertion, whilst smaller headwater catchments gain particularly from ARMA (AutoRegressive Moving Average) error-prediction. An assessment is made of using deterministic rainfall forecasts from NWP UKV - the Numerical Weather Prediction UK Variable Resolution form of the Met Office Unified Model - in a full emulation of G2G in real-time, and using foreknowledge of rainfall observations as a reference baseline. Forecast quality can deteriorate strongly beyond 12 hours, especially for smaller catchments, whilst for some locations good performance is maintained even for long lead-times. Diagnostic analysis reveals that the UKV rainfall forecasts have patterns of overestimation in some lowland areas (e.g. over London) and leeward of high elevation areas (e.g. north and south Pennines). Overall performance is better in Scotland although there is evidence of UKV overestimating rainfall near the coast at Edinburgh and Elgin in the north. The assessment framework is extended to include rainfall forecast ensembles and probabilistic flood forecasting, using a combination of case-study and longer-term analyses. Blended Ensemble rainfall forecasts are assessed in two forms: forecasts out to 24 hours updated 4 times a day, and nowcasts out to 7 hours updated every 15 minutes. The 24 hour forecasts generally perform well as input to G2G in the case studies, the G2G flow forecasts typically signalling a flood peak 12 to 18 hours in advance and ahead of any observed response for small catchments. New regional summary map displays of the probability of flow threshold exceedances over a forecast horizon, and for increasing levels of severity, are developed to highlight evolving hotspots of flood risk over time. The first ever continuous assessment of G2G probability flow forecasts is reported using national maps of probabilistic skill scores - Relative Operating Characteristic (ROC) Skill Score and Brier Skill Score (BSS) - to spatially assess their performance. It is noted that the short periods available for assessment - a 7½ month period over England & Wales and 4 ½ months over Scotland - limit the analyses to low return period flow thresholds. Half the median (2-year) flood is used although a regional pooled analysis allows some assessment up to 5-year. The G2G probability forecast assessed is the probability of the chosen flow threshold being exceeded at any time over the forecast horizon (taken to be 24 hours). Comparison of these scores when applied to deterministic and probabilistic forecasts from G2G provides strong evidence of the value of G2G ensemble forecasts as an indicator of flood risk over Britain. Noticeably poorer performance indicated by the BSS across Scotland is in part attributed to the short, summer-dominated assessment period. Operational tools available to FFC and the SFFS for using G2G flow ensembles are reviewed and options for improvement identified drawing on the experience and findings of the study. This leads to identifying some work of an operational nature for consideration in Phase 3 of the project. The report closes with a summary of project achievements grouped thematically, a set of recommendations both of a general nature and specific to FFC and SFFS needs, and finally some proposals for consideration under Phase 3 of the G2G for Rapid Response Catchments project. Some key benefits arising from the project are summarised below. • Evidence has been produced that shows G2G has good skill in providing strategic forecasts for RRCs. The evidence is stratified by catchment type (area, urbanisation, headwater), form of forecast (simulation or forecast mode) and nature of rainfall input (raingauge, deterministic forecast, ensemble forecast). • Strong evidence has been presented on the advantage of using an ensemble rainfall forecast as input to G2G to obtain a probabilistic flood forecast for an RRC, relative to an approach where only a single deterministic rainfall and flood forecast is obtained. This indicates better guidance can be given on forecast flood risk for RRCs, improving the level of service provision for such catchments which are currently not well served. • An improved G2G model configuration, exploiting gauged flows from 912 sites and including new locally calibrated parameters, has been delivered and made operational for the FFC with England & Wales coverage. The benefit is improved operational flood forecast accuracy. For Scotland, an enhanced configuration will be delivered to SFFS in Spring 2014. • Detailed recommendations on how the visual presentation of G2G ensemble results could be improved are set down in this report. When further developed and implemented, these will prove of benefit to the preparation of Flood Guidance Statements issued by FFC and the SFFS across Britain