Wing shape is an important factor affecting the aerodynamic performance of wings of monocopters and flapping-wing micro air vehicles. Here, an evolutionary structural optimisation method is adapted to optimise wing shape to enhance the lift force due to aerodynamic pressure on the wing surfaces. The pressure distribution is observed to vary with the span-based Reynolds number over a range covering most insects and samaras. Accordingly, the optimised wing shapes derived using this evolutionary approach are shown to adjust with Reynolds number. Moreover, these optimised shapes exhibit significantly higher lift coefficients ( ${\sim}50\,\%$ ) than the initial rectangular wing forebear. Interestingly, the optimised shapes are found to have a large area outboard, broadly in line with the features of high-lift forewings of multi-winged insects. According to specific aerodynamic performance requirements, this novel method could be employed in the optimisation of improved wing shapes for micro air vehicles.

A two-year (2015 and 2016) grazing study was established to compare ewe and lamb performance when grazed on a perennial ryegrass only sward compared to more diverse sward types. In that study four sward types were investigated: a perennial ryegrass (Lolium perenne) only sward receiving 163 kg nitrogen per hectare per year (N/ha/yr) (PRG); a perennial ryegrass and white clover (Trifolium repens) sward receiving 90 kg N/ha/yr (PRGWC); a six species sward (two grasses (perennial ryegrass and timothy (Phleum pratense)), two legumes (white and red clover (Trifolium pratense)) and two herbs (ribwort plantain (Plantago lanceolata) and chicory (Cichorium intybus)) receiving 90 kg N/ha/yr (6S); and a nine species sward containing cocksfoot (Dactylis glomerata), greater birdsfoot trefoil (Lotus pedunculatus) and yarrow (Achillea millefolium) in addition to the six species listed above, receiving 90 kg N/ha/yr (9S). Each sward type was managed as a separate farmlet and stocked with 30 twin-rearing ewes at a stocking rate of 12.5 ewes/ha under rotational grazing management from turnout post-lambing until housing. Lamb live weight was recorded fortnightly and lambs were drafted for slaughter at 45 kg. Ewe live weight and body condition score (BCS) were recorded on five occasions annually. Lamb faecal egg count (FEC) was recorded fortnightly and lambs were treated with anthelmintics when mean lamb FEC per sward type was above 400 eggs per gram. Ewes grazing the 6S and 9S swards had heavier (P < 0.01) live weights and BCS throughout the study than the ewes grazing the PRG sward. Lambs grazing the 6S sward were heavier than lambs grazing all other sward types of 14 weeks old (P < 0.05). Lambs grazing the PRG sward required more days to reach slaughter weight than lambs grazing all other sward types (P < 0.001). Lambs grazing the 6S and 9S swards required fewer anthelmintic treatments than lambs grazing the PRG or PRGWC swards. In conclusion, grazing multispecies swards improved ewe and lamb performance and reduced the requirement for chemical anthelmintics.

The individual and combined influences of aspect ratio ( $A$ ), Reynolds number ( $Re$ ) and Rossby number ( $Ro$ ) on the leading-edge vortex (LEV) of a rotating wing of insect-like planform are investigated numerically. A previous study from our group has determined the wingspan to be an appropriate length scale governing the large-scale LEV structure. In this study, the $A$ range considered is further extended, to show that this scaling works well as $A$ is varied by a factor of 4 ( $1.8\leqslant A\leqslant 7.28$ ) and over a $Re$ range of two orders of magnitude. The present study also extends this scaling for wings with an offset from the rotation axis, which is typically the case for actual insects and often for experiments. Remarkably, the optimum range of $A$ based on the lift coefficients at different $Re$ coincides with that observed in nature. The scaling based on the wingspan is extended to the acceleration terms of the Navier–Stokes equations, suggesting a modified scaling of $Ro$ , which decouples the effects of $A$ . A detailed investigation of the flow structures, by increasing $Ro$ in a wide range, reveals the weakening of the LEV due to the reduced spanwise flow, resulting in a reduced lift. Overall, the use of span-based scaling of $Re$ and $Ro$ , together with $A$ , may help reconcile apparent conflicting trends between observed variations in aerodynamic performance in different sets of experiments and simulations.

Childhood adversity is associated with increased risk for psychopathology. Neurodevelopmental pathways underlying this risk remain poorly understood. A recent conceptual model posits that childhood adversity can be deconstructed into at least two underlying dimensions, deprivation and threat, that are associated with distinct neurocognitive consequences. This model argues that deprivation (i.e., a lack of cognitive stimulation and learning opportunities) is associated with poor executive function (EF), whereas threat is not. We examine this hypothesis in two studies measuring EF at multiple levels: performance on EF tasks, neural recruitment during EF, and problems with EF in daily life. In Study 1, deprivation (low parental education and child neglect) was associated with greater parent-reported problems with EF in adolescents (N = 169; 13–17 years) after adjustment for levels of threat (community violence and abuse), which were unrelated to EF. In Study 2, low parental education was associated with poor working memory (WM) performance and inefficient neural recruitment in the parietal and prefrontal cortex during high WM load among adolescents (N = 51, 13–20 years) after adjusting for abuse, which was unrelated to WM task performance and neural recruitment during WM. These findings constitute strong preliminary evidence for a novel model of the neurodevelopmental consequences of childhood adversity.

A numerical study of the flow-induced vibration of two elastically mounted cylinders in tandem and staggered arrangements at Reynolds number $Re=200$ is presented. The cylinder centres are set at a streamwise distance of 1.5 cylinder diameters, placing the rear cylinder in the near-wake region of the front cylinder for the tandem arrangement. The cross-stream or lateral offset is varied between 0 and 5 cylinder diameters. The two cylinders are identical, with the same elastic mounting, and constrained to oscillate only in the cross-flow direction. The variation of flow behaviours is examined for static cylinders and for elastic mountings of a range of spring stiffnesses, or reduced velocity. At least seven major modes of flow response are identified, delineated by whether the oscillation is effectively symmetric, and the strength of the influence of the flow through the gap between the two cylinders. Submodes of these are also identified based on whether or not the flow remains periodic. More subtle temporal behaviours, such as period doubling, quasi-periodicity and chaos, are also identified and mapped. Across all of these regimes, the amplitudes of vibration and the magnitude of the fluid forces are quantified. The modes identified span the parameter space between two important limiting cases: two static bodies at varying lateral offset; and two elastically mounted bodies in a tandem configuration at varying spring stiffnesses. Some similarity in the response of extremely stiff or static bodies and extremely slack bodies is shown. This is explained by the fact that the slack bodies are free to move to an equilibrium position and stop, effectively becoming a static system. However, the most complex behaviour appears between these limits, when the bodies are in reasonably close proximity, and the natural structural frequency is close to the vortex shedding frequency of a single cylinder. This appears to be driven by the interplay between a series of time scales, including the vortex formation time, the advection time across the gap between the cylinders and the oscillation period of both bodies. This points out an important difference between this multi-body system and the classic single-cylinder vortex-induced vibration: two bodies in close proximity will not oscillate in a synchronised, periodic manner when their natural structural frequencies are close to the nominal vortex shedding frequency of a single cylinder.

Our study aimed to evaluate changes in the epidemiology of pathogens causing surgical site infections (SSIs) in England between 2000 and 2013 in the context of intensified national interventions to reduce healthcare-associated infections introduced since 2006. National prospective surveillance data on target surgical procedures were used for this study. Data on causative organism were available for 72% of inpatient-detected SSIs meeting the standard case definitions for superficial, deep and organ-space infections (9767/13 531) which were analysed for trends. A multivariable logistic linear mixed model with hospital random effects was fitted to evaluate trends by pathogen. Staphylococcus aureus was the predominant cause of SSI between 2000 (41%) and 2009 (24%), decreasing from 2006 onwards reaching 16% in 2013. Data for 2005–2013 showed that the odds of SSI caused by S. aureus decreased significantly by 14% per year [adjusted odds ratio (aOR) 0·86, 95% confidence interval (CI) 0·83–0·89] driven by significant decreases in methicillin-resistant S. aureus (MRSA) (aOR 0·71, 95% CI 0·68–0·75). However a small significant increase in methicillin-sensitive S. aureus was identified (aOR 1·06, 95% CI 1·02–1·10). Enterobacteriaceae were stable during 2000–2007 (12% of cases overall), increasing from 2008 (18%) onwards, being present in 25% of cases in 2013; the model supported these increasing trends during 2007–2013 (aOR 1·12, 95% CI 1·07–1·18). The decreasing trends in S. aureus SSIs from 2006 and the increases in Enterobacteriaceae SSIs from 2008 may be related to intensified national efforts targeted at reducing MRSA bacteraemia combined with changes in antibiotic use aimed at controlling C. difficile infections.

(Astrophys. Letters). The measured amount of band-splitting, Δf, in the spectra of nine harmonic type II bursts is illustrated in Figure 1. Here, as in previous, smaller samples (Roberts, 1959; Maxwell and Thompson, 1962; Weiss, 1965) Δf is found to increase with frequency, f.

Ground-based observations of Type III bursts made with spectrographs and spectro-polarimeters, at frequencies above the ionospheric cut-off, reveal that most bursts (excluding storm Type IIIs) have fundamental (F) and harmonic (H) structure (Wild et al. 1959; Dulk and Suzuki 1980). An example of F-H bursts is given by Sheridan (1978). Such bursts are produced by streams of electrons travelling along open magnetic field lines and exciting plasma oscillations which are converted to electro-magnetic waves at both the F and H frequencies of the local plasma frequency in the corona.

Sources of the Type I storms are thought to lie on closed magnetic loop systems above bipolar sunspots. Usually one sunspot is stronger than the other in the bipolar magnetic structure, and accordingly only one radio source associated with the stronger sunspot is usually observed. Occasionally however a double radio source is observed in conjunction with the bipolar sunspots. In such a case the double radio source should be intrinsically bipolar, viz. the two components should emit opposite senses of circular polarization (in this paper we use the word polarity for simplicity).

We report on the positional and polarization characteristics of Type III bursts in the range 24–220 MHz as measured by the Culgoora radioheliograph, spectrograph and spectropolarimeter. Our study includes 997 bursts which are of two classes: fundamental-harmonic (F-H) pairs and “structureless” bursts with no visible F-H structure. In a paper published elsewhere (Dulk and Suzuki, 1979) we give a detailed description and include observations of source sizes, heights and brightness temperatures. Here we concentrate on the polarization of the bursts and the variation of polarization from centre to limb. The observed centre-to-limb decrease in polarization approximately follows a cosine law. This decrease is not as predicted by simple theory but is consistent with other observations which imply that open field lines from an active region diverge strongly. The observed o-mode polarization of harmonic radiation implies that the wave vectors of Langmuir waves are always parallel, within about 20°, to the magnetic field, while the constancy of H polarization with frequency implies that the ratio fB/fP, the Alfvén speed vA and the plasma beta are constant with height on the open field lines above an active region. Finally, we infer that some factor, in addition to the magnetic field strength, controls the polarization of F radiation.

Data-constrained modeling is a method that enables three-dimensional distribution of mineral phases and porosity in a sample to be modeled based on micro-computed tomography scans acquired at different X-ray energies. Here we describe an alternative method for measuring porosity, synchrotron K-edge subtraction using xenon gas as a contrast agent. Results from both methods applied to the same Darai limestone sample are compared. Reasonable agreement between the two methods and with other porosity measurements is obtained. The possibility of a combination of data-constrained modeling and K-edge subtraction methods for more accurate sample characterization is discussed.

Recent experimental research on rotating cylinder wakes has found that a previously numerically predicted subharmonic instability mode, mode C, occurs for considerably lower rotation rates than predicted through stability analysis, yet other mode transitions occur closer to the predicted onset. One difference between the theoretical and experimental set-ups is the use of a small-diameter hydrogen bubble visualisation wire placed upstream of the rotating cylinder. The current paper tests the hypothesis that a wire, of only $1/100$ th of the cylinder diameter, placed five diameters upstream of the cylinder, sufficiently perturbs the flow to substantially affect certain wake transitions, including the onset of mode C. This is achieved using stability analysis of a flow that includes the upstream wire. The results indeed show that the wire of a tiny diameter induces a non-negligible asymmetry in the flow, triggering the subharmonic mode at substantially lower rotation rates. Furthermore, at higher rotation rates, the onset of two other three-dimensional modes are delayed to higher Reynolds numbers. These results make the point that even seemingly minute perturbations caused by minimally intrusive methods may result in substantially altered experimental flow behaviour.

This study investigates the free transverse flow-induced vibration (FIV) of an elastically mounted low-mass-ratio square cylinder in a free stream, at three different incidence angles: ${{\alpha }}=0^\circ $ , $20^\circ $  and $45^\circ $ . This geometric setup presents a body with an angle of attack, sharp corners and some afterbody, and therefore is a generic body that can be used to investigate a wide range of FIV phenomena. A recent study by Nemes et al. (J. Fluid Mech., vol. 710, 2012, pp. 102–130) provided a broad overview of the flow regimes present as a function of both the angle of attack ${{\alpha }}$  and reduced flow velocity  ${U^{*}}$ . Here, the focus is on the three aforementioned representative angles of attack: ${{\alpha }}=0^\circ $ , where the FIV is dominated by transverse galloping; ${{\alpha }}=45^\circ $ , where the FIV is dominated by vortex-induced vibration (VIV); and an intermediate value of ${{\alpha }}=20^\circ $ , where the underlying FIV phenomenon has previously been difficult to determine. For the ${{\alpha }}=0^\circ $ case, the amplitude of oscillation increases linearly with the flow speed except for a series of regimes that occur when the vortex shedding frequency is in the vicinity of an odd-integer multiple of the galloping oscillation frequency, and the vortex shedding synchronizes to this multiple of the oscillation frequency. It is shown that only odd-integer multiple synchronizations should occur. These synchronizations explain the ‘kinks’ in the galloping amplitude response for light bodies first observed by Bearman et al. (J. Fluids Struct., vol. 1, 1987, pp. 19–34). For the ${{\alpha }}=45^\circ $ case, the VIV response consists of a number of subtle, but distinctly different regimes, with five regimes of high-amplitude oscillations, compared to two found in the classic VIV studies of a circular cylinder. For the intermediate ${{\alpha }}=20^\circ $ case, a typical VIV ‘upper branch’ occurs followed by a ‘higher branch’ of very large-amplitude response. The higher branch is caused by a subharmonic synchronization between the vortex shedding and the body oscillation frequency, where two cycles of vortex shedding occur over one cycle of oscillation. It appears that this subharmonic synchronization is a direct result of the asymmetric body. Overall, the FIV of the square cylinder is shown to be very rich, with a number of distinct regimes, controlled by both ${{\alpha }}$ and ${U^{*}}$ . Importantly, ${{\alpha }}$ controls the underlying FIV phenomenon, as well as controlling the types of possible synchronization between the oscillation and vortex shedding.

The excavations of the cemetery groups at Balneaves, Loanleven and Park of Tongland facilitate an examination of many aspects of Bronze Age burial practices in Scotland. They are notable as much for the differences in burial ritual they imply as for the very narrow chronological period in which they were used. The three sites produced a total of seventeen 14C dates, two of which are aberrant, with means of the remaining fifteen falling within a period of 250 years (3370–3610 bp in radiocarbon years). The excavations were sponsored by Historic Scotland (formerly Historic Buildings and Monuments, Scotland).

At Balneaves, a penannular ditch enclosed sixteen features, including a group of seven pits with cremation burials, four of which were associated with a distinctive assemblage of collared urns. The cremated bone was well preserved. At least one large standing stone had been erected on the site, and this was buried in the medieval period.

At Loanleven, only a segment of the enclosing ring-ditch survived, within which were four cists, two containing inhumations and two cremations, one of the latter (Cist 2) associated with a fragment of a food vessel. A decorated slab, in so-called ‘Passage Grave Style’, was recovered from Cist 1, and the same cist produced palynological evidence for grave furnishings in the form of a mat of plant material which probably underlay the body. 14C dates give a terminus ante quem of 3620±50 bp (GU–2543) for the re-use of the decorated slab, and a terminus post quem of 3410±50 bp (GU–2542) for the food vessel grave.

Park of Tongland, regarded as a Four-Poster stone circle, was excavated after the fall of a standing stone. It was shown to be of multi-period construction, consisting of a cairn which overlay seven pits containing fragmentary cremation burials, two associated with collared urns. The standing stones may not all have been erect at the same time. A series of 14C dates fell within the range of 1480–1530 bc.

A foodborne outbreak with 49 cases (22 culture positive for Campylobacter sp.) following a wedding party in the East of England was investigated. A retrospective cohort study identified an association between consumption of chicken liver pâté and infection with Campylobacter jejuni/coli. There was a statistically significant association between dose (amount of chicken liver pâté eaten) and the risk of disease [‘tasted’: odds ratio (OR) 1·5, 95% confidence interval (CI) 0·04–∞; ‘partly eaten’: OR 8·4, 95% CI 1·4–87·5; ‘most or all eaten’: OR 36·1, 95% CI 3·3–2119). The local authority found evidence that the preparation of chicken livers breached Food Standards Agency's guidelines. This epidemiological investigation established a clear dose–response relationship between consumption of chicken liver pâté and the risk of infection with Campylobacter. The continuing need to raise public awareness of the risk to human health posed by undercooked chicken liver is evident.

Silicon Carbide (SiC) is an emerging semiconductor material which has been widely predicted to be superior to both Si and GaAs in the area of power electronic switching devices [1]. This paper presents an overview of SiC power devices and concludes that MOS Turn-Off Thyristor (MTOTM) is one of the most promising near term SiC switching device given its high power potential, ease of turn-off, 500°C operation and resulting reduction in cooling requirements. It is further concluded that in order to take advantage of SiC power devices, high temperature packages and components with double sided attachment need to be developed along with the SiC power devices.

Chemical analysis on a microscopic scale was performed on a TiN particle sample on silicon and on two patterned samples using a synchrotron source scanning photoemission microscope. For all the experiments, we exploit the ability, developed in our experimental system, to reach specific locations on the wafer and analyze the local chemical state.