175 research outputs found

    Long-term patterns in interpersonal behaviour amongst psychopathic patients in secure inpatient treatment: A follow-up study.

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    Psychopathy is a disorder that is partly defined by with maladaptive interpersonal behaviour and has significant effects on treatment outcomes. A previous study (Draycott et al., ) found that higher levels of psychopathy led to a specific interpersonal 'trajectory' amongst patients in a secure psychiatric treatment programme during the first 9 months of their admission. In that programme, more psychopathic patients became increasingly dominant over time, and less psychopathic patients became increasingly hostile. This study is a longer-term follow-up and extension of that study, extending the window of observation to 33 months of treatment. It was found that the more psychopathic patients' increased dominance returned to baseline levels by 33 months, as did the less psychopathic patients' increased hostility. This suggests that treatment for this group is not idiopathic but leaves unanswered the question as to what these divergent trajectories represent

    A sensitivity analysis of the prediction of the nitrogen fertilizer requirement of cauliflower crops using the HRI WELL_N computer model

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    HRI WELL_N is an easy to use computer model, which has been used by farmers and growers since 1994 to predict crop nitrogen (N) requirements for a wide range of agricultural and horticultural crops. A sensitivity analysis was carried out to investigate the model predictions of the N fertilizer requirement of cauliflower crops, and, at that rate, the yield achieved, yield response to the fertilizer applied, N uptake, NO3-N leaching below 30 and 90 cm and mineral N at harvest. The sensitivity to four input factors – soil mineral N before planting, mineralization rate of soil organic matter, expected yield and duration of growth – was assessed. Values of these were chosen to cover ranges between 40% and 160% of values typical for field crops of cauliflowers grown in East Anglia. The assessments were made for three soils – sand, sandy loam and silt – and three rainfall scenarios – an average year and years with 144% or 56% of average rainfall during the growing season. The sensitivity of each output variable to each of the input factors (and interactions between them) was assessed using a unique ‘sequential' analysis of variance approach developed as part of this research project. The most significant factors affecting N fertilizer requirement across all soil types/rainfall amounts were soil mineral N before planting and expected yield. N requirement increased with increasing yield expectation, and decreased with increasing amounts of soil mineral N before planting. The responses to soil mineral N were much greater when higher yields were expected. Retention of N in the rooting zone was predicted to be poor on light soils in the wettest conditions suggesting that to maximize N use, plants needed to grow rapidly and have reasonable yield potential. Assessment of the potential impacts of errors in the values of the input factors indicated that poor estimation of, in particular, yield expectation and soil mineral N before planting could lead to either yield loss or an increased level of potentially leachable soil mineral N at harvest. The research demonstrates the benefits of using computer simulation models to quantify the main factors for which information is needed in order to provide robust N fertilizer recommendations

    An experimental assessment of the effect of current on wave buoy measurements

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    This is the final version. Available on open access from Elsevier via the DOI in this recordWave measurement buoys provide characterisation of wave climates that forms the basis for the design of offshore systems. These buoys are commonly subjected to currents which affect the resulting wave measurements, and if not accounted for will result in errors in the estimated sea state parameters. The present work provides results and observations from experiments aimed at assessing the impact that currents have on wave buoy measurements, thereby informing processing techniques to more accurately include this effect. Through scaled testing (circa 1:15) in a combined wave–current test tank, buoy motions (diameter, D = 0.24m) are recorded in current only, waves only, and combined wave–current including oblique conditions. From these, the wave-induced motions are extracted and compared against three prediction methods based on established transfer function approaches as well as a frequency-domain hydrodynamic coefficient (HC) model based on potential flow. The scaled buoy was observed to have large, complex, irregular oscillatory vortex-induced motions (VIM) exceeding the buoy diameter. Both the magnitude and frequency of these oscillations was found to be significantly altered by the mooring stiffness and configuration whilst the addition of collinear waves was found not to affect the magnitude of VIM. Furthermore, due to the lack of VIM heave response and a large difference between the frequencies of the vortex-induced and wave induced horizontal motions, it was found that the VIM did not significantly alter the interpretation of the wave climate for the tested conditions. The HC model was found to accurately capture the observed modified hydrodynamics for opposing wave–current conditions, where larger horizontal motions than (typically) predicted are observed for all frequencies. This behaviour is concluded to result from increased excitation forces owing to the higher wavenumbers. The experiments highlight the potential effects of VIM on wave measurement performance of wave buoys, along with the complex and mooring-dependent nature of the response. Altered dynamics in the presence of currents are described which must be accounted for to avoid errors and the presented prediction methods provide a mechanism to account for these effects in wave processing methodologies which can subsequently reduce uncertainty in our understanding of the offshore environment.Engineering and Physical Sciences Research Council (EPSRC

    The SPAIR method: Isolating incident and reflected directional wave spectra in multidirectional wave basins

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    Wave tank tests aiming to reproduce realistic or site specific conditions will commonly involve using directionally spread, short-crested sea states. The measurement of these directional characteristics is required for the purposes of calibrating and validating the modelled sea state. Commonly used methods of directional spectrumreconstruction, based on directional spreading functions, have an inherent level of uncertainty associated with them. In this paper we aim to reduce the uncertainty in directional spectrum validation by introducing the SPAIR (Single-summation PTPD Approach with In-line Reflections) method, in combination with a directional wave gauge array. A variety of wave conditions were generated in the FloWave Ocean Energy Research Facility, Edinburgh, UK, to obtain a range of sea state and reflection scenarios. The presented approach is found to provide improved estimates of directional spectra over standardmethods, reducing the mean apparent directional deviation down to below 6% over the range of sea states. Additionally, the method isolates incident and reflected spectra in both the frequency and time domain, and can separate these wave systems over 360°. The accuracy of themethod is shown to be only slightly sensitive to the level of in-line reflectionpresent,but at present cannot dealwithoblique reflections. The SPAIRmethod, as presented or with slightmodification, will allow complex directional sea states to be validated more effectively, enabling multidirectional wave basins to simulate realistic wave scenarios with increased confidence

    Pregnancy outcomes following different types of bariatric surgery: A national cohort study

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    OBJECTIVE: To assess the impact of type of bariatric surgery on pregnancy outcomes. STUDY DESIGN: This is a national prospective observational study using the UK Obstetric Surveillance System (UKOSS). Data collection was undertaken in 200 consultant-led NHS maternity units between November 2011 and October 2012 (gastric banding), and April 2014 and March 2016 (gastric bypass and sleeve gastrectomy). Participants were pregnant women following gastric banding (n = 127), gastric bypass (n = 134) and sleeve gastrectomy (n = 29). Maternal and perinatal outcomes were compared using generalised linear and linear mixed models. Maternal outcomes included gestational weight gain, pre-eclampsia, gestational diabetes, anaemia, surgical complications. Perinatal outcomes included birthweight, small/large for gestational age (SGA/LGA), preterm birth, stillbirth. RESULTS: Maternal: Women pregnant after gastric banding and sleeve gastrectomy had a lower risk of anaemia compared with gastric bypass (banding (16 %) vs bypass (39 %): p = 0.002, sleeve (21 %) vs bypass: p = 0.04). Gestational diabetes risk was lower after gastric banding compared with gastric bypass (7 % vs 16 %, p = 0.03) despite women with banding having significantly greater weight at booking as well as gestational weight gain. Women pregnant after gastric banding and sleeve gastrectomy had a lower risk of surgical complications than after gastric bypass (banding (0.9 %) vs bypass (11.4 %): p = 0.03, sleeve (0.0 %) vs bypass: p = 0.06). Perinatal: Infants born to mothers after gastric banding had a higher birthweight than those born to mothers after gastric bypass (mean difference = 260 g (125-395), p < 0.001). Infants were more likely to be LGA if their mothers had gastric banding compared with gastric bypass or sleeve gastrectomy (banding (21 %) vs bypass (5 %): p = 0.006; banding vs sleeve (3 %): p = 0.03). Risk of preterm birth was higher in women with gastric banding compared with gastric bypass (13 % vs 8 %, p = 0.04). CONCLUSIONS: Women planning bariatric surgery should be counselled regarding the differing impacts of different types of procedure on any future pregnancy. Pre-existing gastric bypass is associated with higher rates of potentially serious surgical complications during pregnancy

    Experimental data of bottom pressure and free surface elevation including waves and current interaction

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    This is the final version. Available on open access from MDPI via the DOI in this recordData Availability Statement: The data presented in this study are openly available: https://doi.org/10.7488/ds/3120.Abstract: Force plates are commonly used in tank testing to measure loads acting on the foundation of a structure. These targeted measurements are overlaid by the hydrostatic and dynamic pressure acting on the force plate induced by the waves and currents. This paper presents the dataset of bottom force measurement with a six degree-of-freedom force plate (AMTI OR6-7 1000, surface area 0.464 m×0.508 m) combined with synchronised measurements of surface elevation and current velocity. The data covers a wave frequencies between 0.2 to 0.7 Hz and wave direction between 0◦ and 180◦ . These variations are provided for 0 and 0.2 m/s current speed and a variation of current in the absence of waves covering 0 to 0.45 m/s. The dataset can be utilised as a validation dataset for models predicting bottom pressure based on free surface elevation. Additionally, the dataset provides the wave and current induced load acting on the specific load cell and a fixed water depth of 2 m, which can subsequently be removed to obtain the often-desired measurement of structural loadsEngineering and Physical Sciences Research Council (EPSRC

    Wave buoys in current - experimental results and observations

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    This is the author accepted manuscript. The final version is available from EWTEC via the link in this recordWave buoys are used extensively for the characterisation of deployment locations for offshore technologies, where they are subjected to currents in addition to the ocean waves. It has been frequently observed that the measurements from wave buoys are affected by these currents, but the majority of deployed buoys cannot measure, or account for, this effect. Presented here are a series of experiments conducted at the FloWave Ocean Energy Research Facility, deploying a spherical wave buoy scale model with a simplified mooring in a series of combined wave-current sea states. The resulting openaccess dataset provides 6 degree of freedom buoy motion and force data (current only) in addition to wave gauge and acoustic doppler velocimeter measurements of the sea states. Experiments were conducted under a range of combined wave-current conditions with variables including velocity, wave period, and relative wave-current angle. It is observed that vortex induced motions (VIM) are significant and highly sensitive to the mooring configuration and current speed. Nevertheless, the wave-induced response and buoy motion amplitude is found to agree with linear wave-current theory predictions in most following wavecurrent conditions. This agreement is poorer in opposing conditions where larger surge motions than predicted are consistently observed. Wave buoy outputs in directional irregular seas were also found to closely match wave gauge outputs. If properly considered, it is suggested that the effect of the current on existing buoy technologies may be accounted for without hardware modification or additional sensing, but through updated analytical tools.Engineering and Physical Sciences Research Council (EPSRC
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