Electromagnetic field and short-range wake function in a beam pipe of elliptical cross section

Within the ultrarelativistic limit, analytical expressions are found for the high-frequency resistive-wall coupling impedance of an elliptical cross-section vacuum chamber. Subsequently, the corresponding wake functions are derived by performing inverse Fourier transformations numerically. The electromagnetic fields have been developed working out two systems of solutions, namely for the vacuum and for the resistive wall. The constants involved in these systems have been determined by matching boundary conditions at the interface vacuum wall. Several study cases have been considered concerning the aspect ratio of the elliptical cross section and the transverse position of the leading charge in order to exemplify the behavior of the longitudinal and transverse wake functions

Shock Index Values and Trends in Pediatric Sepsis: Predictors or Therapeutic Targets? A retrospective observational study

BACKGROUND: Shock index (SI) (heart rate/systolic blood pressure) has been used to predict outcome in both adult and pediatric sepsis within the intensive care unit (ICU). We aimed to evaluate the utility of SI prior to pediatric ICU (PICU) admission. METHODS: We conducted a retrospective observational study of children referred to a pediatric intensive care transport service (PICTS) between 2005 and 2011. The predictive value of SI, heart rate and blood pressure at three pre-specified time points (at referral to PICTS, at PICTS arrival at the referring hospital, and at PICU admission), and changes in SI between the time points, were evaluated. Death within the first 48 hours of ICU admission (early death) was the primary outcome variable. RESULTS: Over the seven-year period, 572 children with sepsis were referred to the PICTS. Thirty-nine children died prior to transport to a PICU, while 474 were transported alive. Adjusting for age, time-points and time duration in a multi-level regression analysis, SI was significantly higher in those who died early. There was a significant improvement in SI with the transport team in survivors but not in non-survivors. However, the predictive value of a change in SI for mortality was no better than either a change in heart rate or blood pressure. CONCLUSIONS: The absolute or change in SI does not predict early death any more than heart rate and systolic blood pressure individually in children with sepsis

Skyrmion fluctuations at a first-order phase transition boundary

Magnetic skyrmions are topologically protected spin textures with promising prospects for applications in data storage. They can form a lattice state due to competing magnetic interactions and are commonly found in a small region of the temperature - magnetic field phase diagram. Recent work has demonstrated that these magnetic quasi-particles fluctuate at the μeV energy scale. Here, we use a coherent x-ray correlation method at an x-ray free-electron laser to investigate these fluctuations in a magnetic phase coexistence region near a first-order transition boundary where fluctuations are not expected to play a major role. Surprisingly, we find that the relaxation of the intermediate scattering function at this transition differs significantly compared to that deep in the skyrmion lattice phase. The observation of a compressed exponential behavior suggests solid-like dynamics, often associated with jamming. We assign this behavior to disorder and the phase coexistence observed in a narrow field-window near the transition, which can cause fluctuations that lead to glassy behavior

Managing the winter surge in demand for resources

This article evaluates whether providing extra clinical resource during the winter of 2014/15 improved the availability of paediatric intensive care retrieval teams in a North London retrieval service. We explored the potential impact of different staffing patterns in future years to inform service planning. We used retrospective routine data to compare the proportion of referrals refused due to lack of capacity between the winter of 2014/15 and the previous five winters. In the winter of 2014/15, an additional team were on shift for 12% of the time. We compared shifts where the additional team were available in the winter of 2014/15 to similar shifts in previous years. We used mathematical modelling to predict the potential impact of staffing levels in future winters. From 1 November 2014 to 3 January 2015, the service performed 380 emergency retrievals and refused 25 due to no available team (6.2%). The proportion of refusals during shifts with the additional team available in 2014/15 was 4.2% vs 12.4% in similar shifts from 2009/10 to 2013/14 (p = 0.026). Mathematical modelling showed that staffing an additional full-time team could result in 2% of referrals refused compared to 8% without and that much benefit could be obtained by a third team working a 12-hour shift from 10am until 10pm (refusal rate 2.8%)

Evolutionary relationships between Rhynchosporium lolii sp. nov. and other Rhynchosporium species on grass.

Copyright: 2013 King et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedThe fungal genus Rhynchosporium (causative agent of leaf blotch) contains several host-specialised species, including R. commune (colonising barley and brome-grass), R. agropyri (couch-grass), R. secalis (rye and triticale) and the more distantly related R. orthosporum (cocksfoot). This study used molecular fingerprinting, multilocus DNA sequence data, conidial morphology, host range tests and scanning electron microscopy to investigate the relationship between Rhynchosporium species on ryegrasses, both economically important forage grasses and common wild grasses in many cereal growing areas, and other plant species. Two different types of Rhynchosporium were found on ryegrasses in the UK. Firstly, there were isolates of R. commune that were pathogenic to both barley and Italian ryegrass. Secondly, there were isolates of a new species, here named R. lolii, that were pathogenic only to ryegrass species. R. lolii was most closely related to R. orthosporum, but exhibited clear molecular, morphological and host range differences. The species was estimated to have diverged from R. orthosporum ca. 5735 years before the present. The colonisation strategy of all of the different Rhynchosporium species involved extensive hyphal growth in the sub-cuticular regions of the leaves. Finally, new species-specific PCR diagnostic tests were developed that could distinguish between these five closely related Rhynchosporium species.Peer reviewedFinal Published versio