Heat and mass transfer under an infant radiant warmer – Development of a numerical model

This is the post-print version of the final paper published in Medical Engineering & Physics. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2010 Elsevier B.V.The main objectives of this paper are to present a procedure of how to create and set up a model for the physical processes that take place within an infant radiant warmer and to validate that Computational Fluid Dynamics (CFD) can be used to resolve such problems. In this study, the results are obtained for a simplified model, both in terms of the geometry employed and the prescribed boundary conditions. The results were numerically verified in terms of the convergence history, monitor data and the physical correctness. This study shows that the physical situation is unsteady and the results tend to oscillate, almost periodically, around a mean value. The results presented in the paper are found to be in qualitative agreement with the experimental data. This gives us confidence that the techniques employed in this paper are appropriate and form the starting point for the inclusion of more realistic effects, e.g. real shape of the newborn and radiant lamp, heat generated inside the newborn, moisture transport, etc.European Union Marie Curie Fellowship programm

An overview of recent applications of computational modelling in neonatology

This article has been made available through the Brunel Open Access Publishing Fund.This paper reviews some of our recent applications of Computational Fluid Dynamics (CFD) to model heat and mass transfer problems in neonatology and investigates the major heat and mass transfer mechanisms taking place in medical devices such as incubators, radiant warmers and oxygen hoods. It is shown that CFD simulations are very flexible tools that can take into account all modes of heat transfer in assisting neonatal care and improving the design of medical devices.Brunel Open Access Publishing Fun

Health-services utilisation amongst older persons during the last year of life: A population-based study

© 2018 The Author(s). Background: Accurate population-based data regarding hospital-based care utilisation by older persons during their last year of life are important in health services planning. We investigated patterns of acute hospital-based service use at the end of life, amongst older decedents in New South Wales (NSW), Australia. Methods: Data from all persons aged ≥70 years who died in the state of NSW Australia in 2007 were included. Several measures of hospital-based service utilisation during the last year of life were assessed from retrospectively linked data comprising data for all registered deaths, cause of death, hospital care during the last year of life (NSW Admitted Patient Data Collection [APDC] and Emergency Department [ED] Data Collection [EDDC]), and the NSW Cancer Registry. Results: Amongst 34,556 decedents aged ≥70 years, 82% (n = 28,366) had ≥1 hospitalisation during the last year of life (median 2), and 21% > 3 hospitalisations. Twenty-five percent (n = 5485) of decedents attended ED during the last week of life. Overall, 21% had a hospitalisation > 30 days in the last year of life, and 7% spent > 3 months in hospital; 79% had ≥1 ED attendance, 17% > 3. Nine percent (n = 3239) spent time in an intensive care unit. Fifty-three percent (n = 18,437) died in an inpatient setting. Hospital records had referenced palliative care for a fifth (7169) of decedents. Adjusting for age group, sex, place of residence, area-level socioeconomic status, and cause of death, having > 3 hospitalisations during the last year of life was more likely for persons dying from cancer (35% versus 16% non-cancer deaths, adjusted odds ratio [aOR] 2.33), 'younger' old decedents (29% for age 70-79 and 20% for age 80-89 versus 11% for 90+, aOR 2.42 and 1.77 respectively) and males (25% versus 17% females, aOR 1.38). Patterns observed for other hospital-based service use were similar. Conclusions: This population-based study reveals high use of hospital care among older persons during their last year of life, although this decreased with increasing older age, providing important data to inform health services planning for this population, and highlighting aspects requiring further study

Evidence for the classical integrability of the complete AdS(4) x CP(3) superstring

We construct a zero-curvature Lax connection in a sub-sector of the superstring theory on AdS(4) x CP(3) which is not described by the OSp(6|4)/U(3) x SO(1,3) supercoset sigma-model. In this sub-sector worldsheet fermions associated to eight broken supersymmetries of the type IIA background are physical fields. As such, the prescription for the construction of the Lax connection based on the Z_4-automorphism of the isometry superalgebra OSp(6|4) does not do the job. So, to construct the Lax connection we have used an alternative method which nevertheless relies on the isometry of the target superspace and kappa-symmetry of the Green-Schwarz superstring.Comment: 1+26 pages; v2: minor typos corrected, acknowledgements adde

Inspiratory muscle warm-up does not improve cycling time-trial performance

Purpose: This study examined the effects of an active cycling warm-up, with and without the addition of an inspiratory muscle warm-up (IMW), on 10-km cycling time-trial performance

Rare coding SNP in DZIP1 gene associated with late-onset sporadic Parkinson's disease

We present the first application of the hypothesis-rich mathematical theory to genome-wide association data. The Hamza et al. late-onset sporadic Parkinson's disease genome-wide association study dataset was analyzed. We found a rare, coding, non-synonymous SNP variant in the gene DZIP1 that confers increased susceptibility to Parkinson's disease. The association of DZIP1 with Parkinson's disease is consistent with a Parkinson's disease stem-cell ageing theory.Comment: 14 page

Role of Condom Negotiation on Condom use among Women of Reproductive Age in three Districts in Tanzania.

ABSTRACT: BACKGROUND: HIV/AIDS remains being a disease of great public health concern worldwide. In regions such as sub-Saharan Africa (SSA) where women are disproportionately infected with HIV, women are reportedly less likely capable of negotiating condom use. However, while knowledge of condom use for HIV prevention is extensive among men and women in many countries including Tanzania, evidence is limited about the role of condom negotiation on condom use among women in rural Tanzania. METHODS: Data originate from a cross-sectional survey of random households conducted in 2011 in Rufiji, Kilombero and Ulanga districts in Tanzania. The survey assessed health-seeking behaviour among women and children using a structured interviewer-administered questionnaire. A total of 2,614 women who were sexually experienced and aged 15--49 years were extracted from the main database for the current analysis. Linkage between condom negotiation and condom use at the last sexual intercourse was assessed using multivariate logistic regression. RESULTS: Prevalence of condom use at the last sexual intercourse was 22.2% overall, ranging from12.2% among married women to 54.9% among unmarried (single) women. Majority of the women (73.4%) reported being confident to negotiate condom use, and these women were significantly more likely than those who were not confident to have used a condom at the last sexual intercourse (OR = 3.13, 95% CI 2.22-4.41). This effect was controlled for marital status, age, education, religion, number of sexual partners, household wealth and knowledge of HIV prevention by condom use. CONCLUSION: Confidence to negotiate condom use is a significant predictor of actual condom use among women in rural Tanzania. Women especially unmarried ones or those in multiple partnerships should be empowered with condom negotiation skills to enhance their sexual and reproductive health outcomes

Functional divergence in the role of N-linked glycosylation in smoothened signaling

The G protein-coupled receptor (GPCR) Smoothened (Smo) is the requisite signal transducer of the evolutionarily conserved Hedgehog (Hh) pathway. Although aspects of Smo signaling are conserved from Drosophila to vertebrates, significant differences have evolved. These include changes in its active sub-cellular localization, and the ability of vertebrate Smo to induce distinct G protein-dependent and independent signals in response to ligand. Whereas the canonical Smo signal to Gli transcriptional effectors occurs in a G protein-independent manner, its non-canonical signal employs Gαi. Whether vertebrate Smo can selectively bias its signal between these routes is not yet known. N-linked glycosylation is a post-translational modification that can influence GPCR trafficking, ligand responsiveness and signal output. Smo proteins in Drosophila and vertebrate systems harbor N-linked glycans, but their role in Smo signaling has not been established. Herein, we present a comprehensive analysis of Drosophila and murine Smo glycosylation that supports a functional divergence in the contribution of N-linked glycans to signaling. Of the seven predicted glycan acceptor sites in Drosophila Smo, one is essential. Loss of N-glycosylation at this site disrupted Smo trafficking and attenuated its signaling capability. In stark contrast, we found that all four predicted N-glycosylation sites on murine Smo were dispensable for proper trafficking, agonist binding and canonical signal induction. However, the under-glycosylated protein was compromised in its ability to induce a non-canonical signal through Gαi, providing for the first time evidence that Smo can bias its signal and that a post-translational modification can impact this process. As such, we postulate a profound shift in N-glycan function from affecting Smo ER exit in flies to influencing its signal output in mice

Incongruous consultation behaviour: results from a UK-wide population survey

<p>Abstract</p> <p>Background</p> <p>Symptom characteristics are strong drivers of care seeking. Despite this, incongruous consultation behaviour occurs and has implications for both individuals and health-care services. The aim of this study was to determine how frequently incongruous consultation behaviour occurs, to examine whether it is more common for certain types of symptoms and to identify the factors associated with being an incongruous consulter.</p> <p>Methods</p> <p>An age and sex stratified random sample of 8,000 adults was drawn from twenty UK general practices. A postal questionnaire was used to collect detailed information on the presence and characteristics of 25 physical and psychological symptoms, actions taken to manage the symptoms, general health, attitudes to symptom management and demographic/socio-economic details. Two types of incongruous consultation behaviour were examined: i) consultation with a GP for symptoms self-rated as low impact and ii) no consultation with a GP for symptoms self-rated as high impact.</p> <p>Results</p> <p>A fifth of all symptoms experienced resulted in consultation behaviour which was incongruous based on respondents' own rating of the symptoms' impact. Low impact consultations were not common, although symptoms indicative of a potentially serious condition resulted in a higher proportion of low impact consultations. High impact non-consultations were more common, although there was no clear pattern in the type of associated symptoms. Just under half of those experiencing symptoms in the previous two weeks were categorised as an incongruous consulter (low impact consulter: 8.3%, high impact non-consulter: 37.1%). Employment status, having a chronic condition, poor health, and feeling that reassurance or advice from a health professional is important were associated with being a low impact consulter. Younger age, employment status, being an ex-smoker, poor health and feeling that not wasting the GPs time is important were associated with being a high impact non-consulter.</p> <p>Conclusions</p> <p>This is one of the first studies to examine incongruous consultation behaviour for a range of symptoms. High impact non-consultations were common and may have important health implications, particularly for symptoms indicative of serious disease. More research is now needed to examine incongruous consultation behaviour and its impact on both the public's health and health service use.</p

Inhibition of Hedgehog Signaling Decreases Proliferation and Clonogenicity of Human Mesenchymal Stem Cells

Human mesenchymal stem cells (hMSC) have the ability to differentiate into osteoblasts, adipocytes and chondrocytes. We have previously shown that hMSC were endowed with a basal level of Hedgehog signaling that decreased after differentiation of these cells. Since hMSC differentiation is associated with growth-arrest we investigated the function of Hh signaling on cell proliferation. Here, we show that inhibition of Hh signaling, using the classical inhibitor cyclopamine, or a siRNA directed against Gli-2, leads to a decrease in hMSC proliferation. This phenomenon is not linked to apoptosis but to a block of the cells in the G0/G1 phases of the cell cycle. At the molecular level, it is associated with an increase in the active form of pRB, and a decrease in cyclin A expression and MAP kinase phosphorylation. Inhibition of Hh signaling is also associated with a decrease in the ability of the cells to form clones. By contrast, inhibition of Hh signaling during hMSC proliferation does not affect their ability to differentiate. This study demonstrates that hMSC are endowed with a basal Hedgehog signaling activity that is necessary for efficient proliferation and clonogenicity of hMSC. This observation unravels an unexpected new function for Hedgehog signaling in the regulation of human mesenchymal stem cells and highlights the critical function of this morphogen in hMSC biology