Dynamic wetting for continuum hydrodynamics with multi-component Lattice Boltzmann equation simulation method

This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.We present methodological innovations to the multi-component lattice Boltzmann equation simulation method which allow for the simulation of dynamic contact lines in the continuum approximation. The improvements are set-out and verified by quantitative results. They allow the simulator access to an expanded range of simulation parameters like viscosity, viscosity contrast and interfacial tensions, and to obtain data with low levels of interfacial micro-current activity in the region of the dynamic contact line

Near wall hemodynamics: Modelling the glycocalyx and the endothelial surface

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.In this paper a coarse-grained model for blood flow in small arteries is presented. Blood is modelled as a two-component incompressible fluid: the plasma and corpuscular elements dispersed in it. The latter are modelled as deformable liquid droplets having greater density and viscosity. Interfacial surface tension and membrane effects are present to mimic key properties and to avoid droplets’ coalescence. The mesoscopic model also includes the presence of the wavy wall, due to the endothelial cells and incorporates a representation of the glycocalyx, covering the vessel wall. The glycocalyx is modelled as a porous medium, the droplets being subjected to a repulsive elastic force when approaching it, during their transit. Preliminary simulations are intended to show the influence of the undulation on the wall together with that of the glycocalyx

Evaluation of the first automated thyroglobulin assay

The aim of this study was to investigate technical and analytical performance of the first automated thyroglobulin (Tg) assay (DPC-Immulite(R); Diagnostic Products Corporation, Los Angeles, USA). In imprecision studies using several human serum pools ranging from 21 to 58 replicates, a coefficient of variation of 9.0 % was obtained at a mean Tg concentration of 0.84 ng/ml and of 6.1 % at a Tg concentration of 62.1 ng/ml. In a method comparison with a non-automated assay (BRAHMS LUMItest Tg(R), BRAHMS, Berlin, Germany) using 383 sera of 303 patients with thyroid carcinoma, regression analysis according to Passing and Bablock yielded in the following equation: Immulite Tg=1.6 x BRAHMS Tg - 0.1 ng/ml (Pearson's r=0.979). Sera obtained from 59 patients with thyroid carcinoma enabled comparative follow-up studies; in all cases qualitative agreement was found with regard to increase or decrease of serum Tg; in eight cases, however, Tg was detected with the Immulite assay but not with the BRAHMS assay. Further follow-up proved the presence of thyroid tissue in these patients. From these and further methodological data (dilution linearity, interference studies, carry-over study, high-dose hook properties, and short report time) it is concluded that the DPC-Immulite Tg assay meets the requirements of routine diagnostic use

The Red Gown: Reflections on the In/Visibility of Menstruation in Scotland

During the 1990s, 2000s and 2010s, menstruation became more present in public discourse in Scotland. Despite this, little attention has been paid to the complex interplay of visibility and invisibility that characterises menstruation’s place in the nation’s wider cultural landscape. In this article, we explore the context of menstruation in the town of St Andrews specifically and Scotland more broadly, during the late 20th and early 21st century, and ask what this reveals about menstrual absence and presence in public debates. The University of St Andrews lies at the centre of this case study because it has been one of the Scottish institutions that has initiated a rollout of free menstrual products as a result of the Period Products (Free Provision) (Scotland) Act of 2021. The University’s Centre for Contemporary Art also hosted Bee Hughes as artist-in-residence, whose practice focuses on the visible and invisible aspects of menstruation. Although impacted by a university strike and the Covid19 pandemic, our collaboration has explored collections of menstrual culture in Scotland and broader questions of menstrual representation, reflecting on how established symbols with other connotations (notably the ceremonial red gown at the University of St Andrews) might provide a way of thinking about menstrual in/visibility. In this article, we discuss how these histories might be both present (institutionalised) and absent (when not on display). This paper presents our findings, in which the artist documents their first visit to St Andrews prior to the strike and pandemic, in relation to historical and contextual materials we located together

Adrenaline modulates the global transcriptional profile of Salmonella revealing a role in the antimicrobial peptide and oxidative stress resistance responses

<p>Abstract</p> <p>Background</p> <p>The successful interaction of bacterial pathogens with host tissues requires the sensing of specific chemical and physical cues. The human gut contains a huge number of neurons involved in the secretion and sensing of a class of neuroendocrine hormones called catecholamines. Recently, in <it>Escherichia coli </it>O157:H7, the catecholamines adrenaline and noradrenaline were shown to act synergistically with a bacterial quorum sensing molecule, autoinducer 3 (AI-3), to affect bacterial virulence and motility. We wished to investigate the impact of adrenaline on the biology of <it>Salmonella </it>spp.</p> <p>Results</p> <p>We have determined the effect of adrenaline on the transcriptome of the gut pathogen <it>Salmonella enterica </it>serovar Typhimurium. Addition of adrenaline led to an induction of key metal transport systems within 30 minutes of treatment. The oxidative stress responses employing manganese internalisation were also elicited. Cells lacking the key oxidative stress regulator OxyR showed reduced survival in the presence of adrenaline and complete restoration of growth upon addition of manganese. A significant reduction in the expression of the <it>pmrHFIJKLM </it>antimicrobial peptide resistance operon reduced the ability of <it>Salmonella </it>to survive polymyxin B following addition of adrenaline. Notably, both phenotypes were reversed by the addition of the β-adrenergic blocker propranolol. Our data suggest that the BasSR two component signal transduction system is the likely adrenaline sensor mediating the antimicrobial peptide response.</p> <p>Conclusion</p> <p><it>Salmonella </it>are able to sense adrenaline and downregulate the antimicrobial peptide resistance <it>pmr </it>locus through the BasSR two component signalling system. Through iron transport, adrenaline may affect the oxidative stress balance of the cell requiring OxyR for normal growth. Both adrenaline effects can be inhibited by the addition of the β-adrenergic blocker propranolol. Adrenaline sensing may provide an environmental cue for the induction of the <it>Salmonella </it>stress response in anticipation of imminent host-derived oxidative stress. However, adrenaline may also serve in favour of the host defences by lowering antimicrobial peptide resistance and hence documenting for the first time such a function for a hormone.</p

Parenting and child behaviour as predictors of toothbrushing difficulties in young children

Background: Oral disease is one of the most prevalent chronic health conditions affecting children. Twice-daily toothbrushing is recommended to promote good oral health; however, a large proportion of Australian families are not meeting this recommendation. Aim: This study aimed to identify important barriers to regular toothbrushing for young children. Design: In this study, 239 parents of 0- to 4-year-old children completed an online survey that investigated child, family, and parent factors associated with child toothbrushing. Hierarchical linear regression was used to identify predictors of toothbrushing frequency in children and perceived difficulty of the task by parents. Results: We found that parent factors, specifically oral health knowledge, were the most significant predictors of toothbrushing frequency. Conversely, parent factors did not contribute significantly to the prediction of perceived difficulty of toothbrushing once family and child factors were taken into account. Oral health knowledge and use of routines were identified as the most important predictors of toothbrushing frequency, whereas resistant child behaviour and household organisation were found to be the most important predictors of perceived difficulty of regular toothbrushing. Conclusions: The findings of the study have implications for behavioural interventions to support parents, as well as directions for future research