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Iron and steel slags have a long history of both disposal and beneficial use in the coastal zone. Despite the large volumes of slag deposited, comprehensive assessments of potential risks associated with metal(loid) leaching from iron and steel by-products are rare for coastal systems. This study provides a national-scale overview of the 14 known slag deposits in the coastal environment of Great Britain (those within 100 m of the mean high-water mark), comprising geochemical characterisation and leaching test data (using both low and high ionic strength waters) to assess potential leaching risks. The seaward facing length of slag deposits totalled at least 76 km, and are predominantly composed of blast furnace (iron-making) slags from the early to mid-20th Century. Some of these form tidal barriers and formal coastal defence structures, but larger deposits are associated with historical coastal disposal in many former areas of iron and steel production, notably the Cumbrian coast of England. Slag deposits are dominated by melilite phases (e.g. gehlenite), with evidence of secondary mineral formation (e.g. gypsum, calcite) indicative of weathering. Leaching tests typically show lower element (e.g. Ba, V, Cr, Fe) release under seawater leaching scenarios compared to deionised water, largely ascribable to the pH buffering provided by the former. Only Mn and Mo showed elevated leaching concentrations in seawater treatments, though at modest levels (<3 mg/L and 0.01 mg/L, respectively). No significant leaching of potentially ecotoxic elements such as Cr and V (mean leachate concentrations <0.006 mg/L for both) were apparent in seawater, which micro-X-Ray Absorption Near Edge Structure (μXANES) analysis show are both present in slags in low valence (and low toxicity) forms. Although there may be physical hazards posed by extensive erosion of deposits in high-energy coastlines, the data suggest seawater leaching of coastal iron and steel slags in the UK is likely to pose minimal environmental risk. [ABSTRACT FROM AUTHOR]

Clumped isotope values (Δ47) of carbonates forming in high pH conditions do not correspond to mineral precipitation temperatures due to certain effects including kinetic isotope fractionation and dissolved inorganic carbon (DIC) endmember mixing. Field-based archives of these carbonate environments are needed to evaluate and quantify these effects accurately. In this study, we measure the clumped isotope values of anthropogenic carbonates for the first time. Tufa layers were analyzed from samples precipitating in a high pH (>10) stream that drains a major slag heap in north east England. Δ47 values are 0.044‰–0.183‰ higher than expected equilibrium values. Non-linear distribution of clumped isotope data is diagnostic of DIC endmember mixing, rather than partial equilibration of DIC. Episodic dilution of hydroxide-rich stream waters by equilibrated rainfall surface runoff provides the mechanism by which mixing occurs. Δ47 values are ~0.010‰–0.145‰ higher than linear clumped isotope mixing profiles, suggesting that the majority of Δ47 increase results from a combination of endmember non-linear mixing effects and an atmosphere-hydroxide sourcing of DIC. The diagnostic trends and variation in clumped isotope values present in these results demonstrates the potential of anthropogenic carbonate systems as a useful archive for studying and quantifying kinetic effects in clumped isotopes. [ABSTRACT FROM AUTHOR]

The estimated response of large-scale engineering structures to severe wind loads is prone to modelling uncertainties that can only ultimately be assessed by full-scale testing. To this end ambient vibration data from full-scale monitoring of the historic Clifton Suspension Bridge has been analysed using a combination of a frequency domain system identification method and a more elaborate stochastic identification technique. There is evidence of incipient coupling action between the first vertical and torsional modes in strong winds, providing unique full-scale data and making this an interesting case study. Flutter derivative estimation, which has rarely previously been attempted on full-scale data, was performed to provide deeper insight into the bridge aerodynamic behaviour, identifying trends towards flutter at higher wind speeds. It is shown that, as for other early suspension bridges with bluff cross-sections, single-degree-of-freedom flutter could potentially occur at wind speeds somewhat below requirements for modern designs. The analysis also demonstrates the viability of system identification techniques for extracting valuable results from full-scale data. [ABSTRACT FROM AUTHOR]

On its opening day, the London Millennium Bridge (LMB) experienced unexpected large amplitude lateral vibrations due to crowd loading. This form of pedestrian-structure interaction has since been identified on several other bridges of various structural forms. The mechanism has generally been attributed to 'pedestrian synchronous lateral excitation' or 'pedestrian lock-in'. However, some of the more recent site measurements have shown a lack of evidence of pedestrian synchronization, at least at the onset of the behaviour. This paper considers a simple model of human balance from the biomechanics field--the inverted pendulum model--for which the most effective means of lateral stabilization is by the control of the position, rather than the timing, of foot placement. The same balance strategy as for normal walking on a stationary surface is applied to walking on a laterally oscillating bridge. As a result, without altering their pacing frequency, averaged over a large number of cycles, the pedestrian effectively acts as a negative (or positive) damper to the bridge motion, which may be at a different frequency. This is in agreement with the empirical model developed by Arup from the measurements on the LMB, leading to divergent amplitude vibrations above a critical number of pedestrians. [ABSTRACT FROM AUTHOR]

Detailed vibration measurements were taken on the Clifton Suspension Bridge in Bristol, England to define its basic dynamic characteristics in normal conditions and then to assess its dynamic response to crowd loading; 27 vibration modes were identified with natural frequencies below 3 Hz. When subject to crowd loading, quite large lateral vibrations occurred in two modes, with sudden onset. This phenomenon, often termed 'synchronous lateral excitation' or 'pedestrian lock-in', is similar to the behaviour observed on the London Millennium Bridge and a number of other bridges. Data analysis showed the behaviour to be consistent with the pedestrian negative damping model proposed by Arup in developing a solution for the Millennium Bridge. This model does not, however, explain the underlying mechanism causing the excitation, and a number of observations of the behaviour of the Clifton Suspension Bridge suggest that significant synchronisation of pedestrians did not actually occur. Although synchronisation may occur for large-amplitude vibrations on some bridges, the observations challenge the commonly held view that this mechanism is responsible for the initial rapid onset of lateral vibrations due to crowd loading. [ABSTRACT FROM AUTHOR]

Introduction: Traditionally, patients are kept nil-per-os/nil-by-mouth (NPO/NBM) prior to invasive cardiac procedures, yet there exists neither evidence nor clear guidance about the benefits of this practice., Objectives: To demonstrate that percutaneous cardiac catheterisation does not require prior fasting., Methods: The data source is a retrospective analysis of data registry of consecutive patients who underwent percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) and stable angina at two district general hospitals in the UK with no on-site cardiac surgery services., Results: A total of 1916 PCI procedures were performed over a 3-year period. None of the patients were kept NPO/NBM prior to their coronary procedures. The mean age was 67±16 years. 1349 (70%) were men; 38.5% (738/1916) had chronic stable angina, while the rest had ACS. 21% (398/1916) were diabetics while 53% (1017/1916) were hypertensive. PCI was technically successful in 95% (1821/1916) patients. 88.5% (1697/1916) had transradial approach. 77% (570/738) of elective PCI patients were discharged within 6 h postprocedure. No patients required emergency endotracheal intubation and there were no occurrences of intraprocedural or postprocedural aspiration pneumonia., Conclusions: Our observational study demonstrates that patients undergoing PCI do not need to be fasted prior to their procedures.

Introduction: Medical student numbers in Britain are increasing rapidly, beyond the capacity of most teaching hospitals, with more clinical teaching taking place in district general hospitals (DGHs). Surveys show that students value the intensive clinical teaching, smaller student numbers and perceived greater friendliness in DGHs. This paper explores DGH staff attitudes to teaching--their level of initial enthusiasm, their attitudes to current teaching, its effect on the hospital and to the sustainability of DGH undergraduate teaching--as both student numbers and service workloads continue to rise., Methods: Semi-structured interviews with 6 key informants were used to generate themes for a 19-question pre-piloted anonymous postal questionnaire sent to all 68 staff involved in undergraduate medical teaching in Northampton General Hospital., Results: The total response included 85% of consultants. Responses in the 3 staff groups were similar. Most respondents felt enthusiastic at the prospect of medical students, although they realised that this would be intellectually challenging and increase time pressures. These predictions were largely fulfilled. Respondents felt that in comparison to teaching hospitals the DGH teaching was more clinically based and consultant-led, with more approachable staff. Currently 41 respondents (82%) felt that they had inadequate teaching time. A majority felt that the arrival of students had improved patient care and that their department had benefited. Thirty-seven responders (74%) felt that the planned doubling of student numbers would impose an unsustainable departmental load, and would compromise teaching quality. The change felt most necessary to support additional teaching was increased clinical medical staff. Better co-ordination between the DGH and the medical school was also felt necessary. The most popular choice for the distribution of extra teaching finance was to the teacher's directorate, i.e. speciality [33 (66%)]. Forty-four (86%) felt that increased student numbers would have a significant impact on the character of the hospital. The 108 free-text comments (2.1 per respondent) centred on hospital character and the benefits of students., Conclusions: This study shows a considerable initial enthusiasm for teaching in DGH staff, which is persisting despite increasing student numbers. However, the current teaching load is seen to be substantial. Teaching more students is likely to produce major problems, based on lack of teaching time and increasingly heavy service commitments rather than lack of patients. This is likely to be a widespread problem for DGHs. Failure to ensure adequate teaching staff and facilities as well as co-ordination could threaten the sustainability of this potentially valuable teaching initiative.

Background: Parents and professionals can both play a role in improving children's expressive language development and a number of alternative models of delivery exist that involve different levels of input by these two groups. However, these alternative treatments have not been subject to rigorous comparative analysis in terms of both cost and clinical effectiveness., Aims: To compare, from the viewpoint of the healthcare provider, parent-based intervention (PBI) for preschool children presenting with expressive language delay with current practice observed in an actual healthcare setting where parents of the child follow a professional's advice on a review basis., Methods & Procedures: Two groups of children were compared on a variety of expressive and receptive language assessment measures. One group (n=10) received standard individual general care. The comparison group (n=12) received PBI., Outcomes & Results: After the 6-month study, the results indicated that children who received PBI made significantly greater language gains that children who received current practice. In addition, a cost-effective analysis was conducted. This showed that although the language gains delivered by PBI did incur some additional costs for the healthcare provider, there was no significant increase in cost per outcome gain over general care., Conclusions: Options in the implementation of PBI are discussed that could potentially save costs for the healthcare providers and increase the value of a PBI-based approach.