378 research outputs found

    A treecode to simulate dust-plasma interactions

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    The interaction of a small object with surrounding plasma is an area of plasma-physics research with a multitude of applications. This paper introduces the plasma octree code pot , a microscopic simulator of a spheroidal dust grain in a plasma. pot uses the Barnes-Hut treecode algorithm to perform N -body simulations of electrons and ions in the vicinity of a chargeable spheroid, employing also the Boris particle-motion integrator and Hutchinson's reinjection algorithm from SCEPTIC; a description of the implementation of all three algorithms is provided. We present results from pot simulations of the charging of spheres in magnetized plasmas, and of spheroids in unmagnetized plasmas. The results call into question the validity of using the Boltzmann relation in hybrid PIC codes

    Dates, Diet, and Dismemberment: Evidence from the Coldrum Megalithic Monument, Kent

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    We present radiocarbon dates, stable isotope data, and osteological analysis of the remains of a minimum of 17 individuals deposited in the western part of the burial chamber at Coldrum, Kent. This is one of the Medway group of megalithic monuments – sites with shared architectural motifs and no very close parallels elsewhere in Britain – whose location has been seen as important in terms of the origins of Neolithic material culture and practices in Britain. The osteological analysis identified the largest assemblage of cut-marked human bone yet reported from a British early Neolithic chambered tomb; these modifications were probably undertaken as part of burial practices. The stable isotope dataset shows very enriched & 15N values, the causes of which are not entirely clear, but could include consumption of freshwater fish resources. Bayesian statistical modelling of the radiocarbon dates demonstrates that Coldrum is an early example of a British Neolithic burial monument, though the tomb was perhaps not part of the earliest Neolithic evidence in the Greater Thames Estuary. The site was probably initiated after the first appearance of other early Neolithic regional phenomena including an inhumation burial, early Neolithic pottery and a characteristic early Neolithic post-and-slot structure, and perhaps of Neolithic flint extraction in the Sussex mines. Coldrum is the only site in the Medway monument group to have samples which have been radiocarbon dated, and is important both for regional studies of the early Neolithic and wider narratives of the processes, timing, and tempo of Neolithisation across Britai

    Work in Britain’s informal economy: learning from road-side hand car washes

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    The UK has over 10,000 Hand Car Washes (HCWs). This article examines two research questions; what do HCWs reveal about the informalization of employment? and what is the prospect of regulation of them? Setting HCWs in a theoretical framework shows that they are part of a growing industry It is becoming an increasingly familiar and visible part of the economy, and is able to use informalization in employment where control of labour costs is a key factor. Employers make a strategic choice to engage precarious and vulnerable usually migrant labour securing further competitive advantage at the cost of pronounced labour exploitation and long hours – the tendency towards informalization. Therein a low-cost business model disciplines competition to usurp higher productivity mechanized car washing

    A randomised controlled study of the effectiveness of breathing retraining exercises taught by a physiotherapist either by instructional DVD or in face-to-face sessions in the management of asthma in adults.

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    BACKGROUND: Asthma control is suboptimal, resulting in quality of life (QoL) impairment and costs. Breathing retraining exercises have evidence of effectiveness as adjuvant treatment, but are infrequently used. OBJECTIVES: To transfer the contents of a brief (three-session) physiotherapist-delivered breathing retraining programme to a digital versatile disc (DVD) and booklet format; to compare the effectiveness of the self-guided intervention with that of 'face-to-face' physiotherapy and usual care for QoL and other asthma-related outcomes; to perform a health economic assessment of both interventions; and to perform a process evaluation using quantitative and qualitative methods. DESIGN: Parallel-group three-arm randomised controlled trial. SETTING: General practice surgeries in the UK. PARTICIPANTS: In total, 655 adults currently receiving asthma treatment with impaired asthma-related QoL were randomly allocated to the DVD (n = 261), physiotherapist (n = 132) and control (usual care) (n = 262) arms in a 2 : 1 : 2 ratio. It was not possible to blind participants but data collection and analysis were performed blinded. INTERVENTIONS: Physiotherapy-based breathing retraining delivered through three 'face-to-face' respiratory physiotherapist sessions or a self-guided programme (DVD plus our theory-based behaviour change booklet) developed by the research team, with a control of usual care. MAIN OUTCOME MEASURES: The primary outcome measure was asthma-specific QoL, measured using the Asthma Quality of Life Questionnaire (AQLQ). Secondary outcomes included asthma symptom control [Asthma Control Questionnaire (ACQ)], psychological state [Hospital Anxiety and Depression Scale (HADS)], hyperventilation symptoms (Nijmegen questionnaire), generic QoL [EuroQol-5 Dimensions (EQ-5D)], assessments of airway physiology (spirometry) and inflammation (exhaled nitric oxide) and health resource use and costs. Assessments were carried out at baseline and at 3, 6 and 12 months post randomisation. Patient engagement and experience were also assessed using quantitative and qualitative methods. RESULTS: Primary efficacy analysis was between-group comparison of changes in AQLQ scores from baseline to 12 months in the intention-to-treat population with adjustments for prespecified covariates. Significant improvements occurred in the DVD group compared with the control group [adjusted mean difference 0.28, 95% confidence interval (CI) 0.11 to 0.44; p < 0.001] and in the face-to-face physiotherapy group compared with the control group (adjusted mean difference 0.24, 95% CI 0.04 to 0.44; p < 0.05), with equivalence between the DVD and the face-to-face physiotherapy groups (adjusted mean difference 0.04, 95% CI -0.16 to 0.24). In all sensitivity analyses, both interventions remained significantly superior to the control and equivalence between the interventions was maintained. In other questionnaire outcome measures and in the physiological measures assessed, there were no significant between-group differences. Process evaluations showed that participants engaged well with both of the active interventions, but that some participants in the DVD arm would have liked to receive tuition from a professional. Asthma health-care costs were lower in both intervention arms than in the control group, indicating 'dominance' for both of the interventions compared with the control, with lowest costs in the DVD arm. The rate of adverse events was lower in the DVD and face-to-face physiotherapy groups than in the control group. CONCLUSIONS: Only 10% of the potentially eligible population responded to the study invitation. However, breathing retraining exercises improved QoL and reduced health-care costs in adults with asthma whose condition remains uncontrolled despite standard pharmacological therapy, were engaged with well by patients and can be delivered effectively as a self-guided intervention. The intervention should now be transferred to an internet-based platform and implementation studies performed. Interventions for younger patients should be developed and trialled. TRIAL REGISTRATION: Current Controlled Trials ISRCTN88318003. FUNDING: This project was primarily funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 53. See the NIHR Journals Library website for further project information. Additional financial support was received from Comprehensive Local Research Networks

    From Lateral Flow Devices to a Novel Nano-Color Microfluidic Assay

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    Improving the performance of traditional diagnostic lateral flow assays combined with new manufacturing technologies is a primary goal in the research and development plans of diagnostic companies. Taking into consideration the components of lateral flow diagnostic test kits; innovation can include modification of labels, materials and device design. In recent years, Resonance-Enhanced Absorption (REA) of metal nano-particles has shown excellent applicability in bio-sensing for the detection of a variety of bio-molecular binding interactions. In a novel approach, we have now integrated REA-assays in a diagnostic microfluidic setup thus resolving the bottleneck of long incubation times inherent in previously existing REA-assays and simultaneously integrated automated fabrication techniques for diagnostics manufacture. Due to the roller-coating based technology and chemical resistance, we used PET-co-polyester as a substrate and a CO2 laser ablation system as a fast, highly precise and contactless alternative to classical micro-milling. It was possible to detect biological binding within three minutes – visible to the eye as colored text readout within the REA-fluidic device. A two-minute in-situ silver enhancement was able to enhance the resonant color additionally, if required

    Modulation of lung inflammation by vessel dilator in a mouse model of allergic asthma

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    <p>Abstract</p> <p>Background</p> <p>Atrial natriuretic peptide (ANP) and its receptor, NPRA, have been extensively studied in terms of cardiovascular effects. We have found that the ANP-NPRA signaling pathway is also involved in airway allergic inflammation and asthma. ANP, a C-terminal peptide (amino acid 99–126) of pro-atrial natriuretic factor (proANF) and a recombinant peptide, NP73-102 (amino acid 73–102 of proANF) have been reported to induce bronchoprotective effects in a mouse model of allergic asthma. In this report, we evaluated the effects of vessel dilator (VD), another N-terminal natriuretic peptide covering amino acids 31–67 of proANF, on acute lung inflammation in a mouse model of allergic asthma.</p> <p>Methods</p> <p>A549 cells were transfected with pVD or the pVAX1 control plasmid and cells were collected 24 hrs after transfection to analyze the effect of VD on inactivation of the extracellular-signal regulated receptor kinase (ERK1/2) through western blot. Luciferase assay, western blot and RT-PCR were also performed to analyze the effect of VD on NPRA expression. For determination of VD's attenuation of lung inflammation, BALB/c mice were sensitized and challenged with ovalbumin and then treated intranasally with chitosan nanoparticles containing pVD. Parameters of airway inflammation, such as airway hyperreactivity, proinflammatory cytokine levels, eosinophil recruitment and lung histopathology were compared with control mice receiving nanoparticles containing pVAX1 control plasmid.</p> <p>Results</p> <p>pVD nanoparticles inactivated ERK1/2 and downregulated NPRA expression in vitro, and intranasal treatment with pVD nanoparticles protected mice from airway inflammation.</p> <p>Conclusion</p> <p>VD's modulation of airway inflammation may result from its inactivation of ERK1/2 and downregulation of NPRA expression. Chitosan nanoparticles containing pVD may be therapeutically effective in preventing allergic airway inflammation.</p
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