Contact and channel modelling to support the early design of technical systems

The early design of mechanical systems is critical because it constrains options later in the design process. In this early stage of the design process, designers must consider customer requirements, how they are related to system functionality and how these requirements and functions are implemented in the physical interactions between components and sub-systems. This paper proposes an approach by which the Contact and Channel Model (C&CM) can be applied to support this stage of embodiment design. The proposed approach is implemented in a computer support tool and illustrated through a simple example. A number of opportunities for further work to extend and evaluate the approach are identified. We argue that our approach offers a unique way to consider the functionality of a design alongside the parts, surfaces and physical effects which embody that functionality, and provides an intuitive representation which could help designers iteratively develop and express this relationship

Not surgical technique, but etiology, contralateral MRI, prior surgery, and side of surgery determine seizure outcome after pediatric hemispherotomy

OBJECTIVE: We aimed to assess determinants of seizure outcome following pediatric hemispherotomy in a contemporary cohort. METHODS: We retrospectively analyzed the seizure outcomes of 457 children who underwent hemispheric surgery in five European epilepsy centers between 2000 and 2016. We identified variables related to seizure outcome through multivariable regression modeling with missing data imputation and optimal group matching, and we further investigated the role of surgical technique by Bayes factor (BF) analysis. RESULTS: One hundred seventy seven children (39%) underwent vertical and 280 children (61%) underwent lateral hemispherotomy. Three hundred forty-four children (75%) achieved seizure freedom at a mean follow-up of 5.1 years (range 1 to 17.1). We identified acquired etiology other than stroke (odds ratio [OR] 4.4, 95% confidence interval (CI) 1.1-18.0), hemimegalencephaly (OR 2.8, 95% CI 1.1-7.3), contralateral magnetic resonance imaging (MRI) findings (OR 5.5, 95% CI 2.7-11.1), prior resective surgery (OR 5.0, 95% CI 1.8-14.0), and left hemispherotomy (OR 2.3, 95% CI 1.3-3.9) as significant determinants of seizure recurrence. We found no evidence of an impact of the hemispherotomy technique on seizure outcome (the BF for a model including the hemispherotomy technique over the null model was 1.1), with comparable overall major complication rates for different approaches. SIGNIFICANCE: Knowledge about the independent determinants of seizure outcome following pediatric hemispherotomy will improve the counseling of patients and families. In contrast to previous reports, we found no statistically relevant difference in seizure-freedom rates between the vertical and horizontal hemispherotomy techniques when accounting for different clinical features between groups

A multi-centre qualitative study exploring the experiences of UK South Asian and White Diabetic Patients referred for renal care

Background An exploration of renal complications of diabetes from the patient perspective is important for developing quality care through the diabetic renal disease care pathway. Methods Newly referred South Asian and White diabetic renal patients over 16 years were recruited from nephrology outpatient clinics in three UK centres - Luton, West London and Leicester – and their experiences of the diabetes and renal care recorded. A semi-structured qualitative interview was conducted with 48 patients. Interview transcripts were analysed thematically and comparisons made between the White and South Asian groups. Results 23 South Asian patients and 25 White patients were interviewed. Patient experience of diabetes ranged from a few months to 35 years with a mean time since diagnosis of 12.1 years and 17.1 years for the South Asian and White patients respectively. Confusion emerged as a response to referral shared by both groups. This sense of confusion was associated with reported lack of information at the time of referral, but also before referral. Language barriers exacerbated confusion for South Asian patients. Conclusions The diabetic renal patients who have been referred for specialist renal care and found the referral process confusing have poor of awareness of kidney complications of diabetes. Healthcare providers should be more aware of the ongoing information needs of long term diabetics as well as the context of any information exchange including language barriers

Discovertebral (Andersson) lesions in severe ankylosing spondylitis: a study using MRI and conventional radiography

The objective of this study is to investigate the prevalence of Andersson lesions (AL) in ankylosing spondylitis (AS) patients who will start anti-tumor necrosis factor (TNF) treatment. Radiographs and magnetic resonance imaging (MRI) of the spine were performed before therapy with anti-TNF. ALs were defined as discovertebral endplate destructions on MRI, associated with bone marrow edema and fat replacement or sclerosis, a decreased signal on T1, enhancement after contrast administration (gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA)), and increased signal on T2 and short tau inversion recovery (STIR). Additionally, conventional radiography showed a fracture line, irregular endplates, and increased sclerosis of adjacent vertebral bodies. Fifty-six AS patients were included, 68% males, mean age of 43 years, and mean disease duration of 11 years. The mean bath ankylosing spondylitis disease activity index was 6.4, and 24% of all patients had ankylosis. Only one patient showed a discovertebral abnormality with bone marrow edema of more than 50% of the vertebral bodies adjacent to the intervertebral disk of T7/T8 and T9/T10, a hypodense signal area on T1, and a high signal on STIR. Irregular endplates were depicted, and T1 after Gd-DTPA demonstrated high signal intensity around the disk margins. However, no fracture line was visible on conventional radiology, and therefore, this case was not considered to be an AL. No AL was detected in our AS patients, who were candidates for anti-TNF treatment. One patient showed a discovertebral abnormality on MRI, without a fracture line on conventional radiology. The relative small proportion of patients with a long-established disease might explain this finding for, particularly, an ankylosed spine is prone to develop an AL

Chiral Nonet Mixing in pi pi Scattering

Pion pion scattering is studied in a generalized linear sigma model which contains two scalar nonets (one of quark-antiquark type and the other of diquark-antidiquark type) and two corresponding pseudoscalar nonets. An interesting feature concerns the mixing of the four isosinglet scalar mesons which yield poles in the scattering amplitude. Some realism is introduced by enforcing exact unitarity via the K-matrix method. It is shown that a reasonable agreement with experimental data is obtained up to about 1 GeV. The poles in the unitarized scattering amplitude are studied in some detail. The lowest pole clearly represents the sigma meson (or f0(600)) with a mass and decay width around 500 MeV. The second pole invites comparison with the f0(980) which has a mass around 1 GeV and decay width around 100 MeV. The third and fourth poles, resemble some of the isosinglet state in the complicated 1-2 GeV region. Some comparison is made to the situation in the usual SU(3) linear sigma model with a single scalar nonet

Room temperature chiral magnetic skyrmion in ultrathin magnetic nanostructures

Magnetic skyrmions are chiral spin structures with a whirling configuration. Their topological properties, nanometer size and the fact that they can be moved by small current densities have opened a new paradigm for the manipulation of magnetisation at the nanoscale. To date, chiral skyrmion structures have been experimentally demonstrated only in bulk materials and in epitaxial ultrathin films and under external magnetic field or at low temperature. Here, we report on the observation of stable skyrmions in sputtered ultrathin Pt/Co/MgO nanostructures, at room temperature and zero applied magnetic field. We use high lateral resolution X-ray magnetic circular dichroism microscopy to image their chiral N\'eel internal structure which we explain as due to the large strength of the Dzyaloshinskii-Moriya interaction as revealed by spin wave spectroscopy measurements. Our results are substantiated by micromagnetic simulations and numerical models, which allow the identification of the physical mechanisms governing the size and stability of the skyrmions.Comment: Submitted version. Extended version to appear in Nature Nanotechnolog

Recurrent neck abscesses due to cervical tuberculous lymphadenopathy in an elderly woman post-splenectomy: a case report

<p>Abstract</p> <p>Introduction</p> <p>There are approximately 7000 new cases of tuberculosis every year in the UK, the majority of which are pulmonary. Approximately 5% affect the lymph nodes in immunocompetent patients. Scrofula is an old term used to describe lymph nodes of the neck infected with tuberculosis</p> <p>Case presentation</p> <p>In the elderly population, growing neck lumps are always treated as red flags until a diagnosis is confirmed. Here, the case of an 89-year-old Caucasian woman is presented. She was reluctant to seek medical help as she feared the cause was sinister and did not want surgical intervention.</p> <p>Conclusion</p> <p>It is difficult to culture tuberculosis from superficial swabs, resulting in a high proportion of false negative results. Where there is a high degree of clinical suspicion for tuberculosis, it is important to consider a biopsy with culture. Patients over the age of 65 have waning immunity and are therefore a vulnerable group for acute infections as well as the re-activation of indolent organisms. Post-splenectomy patients are at a major disadvantage during sepsis and when a cellular immune response is required, such as when faced with a <it>Mycobacterium tuberculosis </it>infection. Scrofula is treated with a similar regime as pulmonary tuberculosis and has a near 100% success rate.</p

On the gauge boson's properties in a candidate technicolor theory

The technicolor scenario replaces the Higgs sector of the standard model with a strongly interacting sector. One candidate for a realization of such a sector is two-technicolor Yang-Mills theory coupled to two degenerate flavors of adjoint, massless techniquarks. Using lattice gauge theory the properties of the technigluons in this scenario are investigated as a function of the techniquark mass towards the massless limit. For that purpose the minimal Landau gauge two-point and three-point correlation functions are determined, including a detailed systematic error analysis. The results are, within the relatively large systematic uncertainties, compatible with a behavior very similar to QCD at finite techniquark mass. However, the limit of massless techniquarks exhibits features which could be compatible with a (quasi-)conformal behavior.Comment: 27 pages, 17 figures, 1 table; v2: persistent notational error corrected, some minor modification

Steps toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. XII. Ground-Based Monitoring of 3C 390.3

Results of a ground-based optical monitoring campaign on 3C 390.3 in 1994-95 are presented. The broad-band fluxes (B, V, R, and I), the spectrophotometric optical continuum flux F(5177) and the integrated emission-line fluxes of Ha, Hb, Hg, HeI, and HeII all show a nearly monotonic increase with episodes of milder short-term variations superposed. The amplitude of the continuum variations increases with decreasing wavelength (4400-9000 A). The optical continuum variations follow the variations in the ultraviolet and X-ray with time delays, measured from the centroids of the cross- correlation functions, typically around 5 days, but with uncertainties also typically around 5 days; zero time delay between the high-energy and low-energy continuum variations cannot be ruled out. The strong optical emission lines Ha, Hb, Hg, and HeI respond to the high-energy continuum variations with time delays typically about 20 days, with uncertainties of about 8 days. There is some evidence that HeII responds somewhat more rapidly, with a time delay of around 10 days, but again, the uncertainties are quite large (~8 days). The mean and rms spectra of the Ha and Hb line profiles provide indications for the existence of at least three distinct components located at +-4000 and 0 km/s relative to the line peak. The emission-line profile variations are largest near line center.Comment: 42 pages (Latex), 13 figures, 14 table