1,128 research outputs found
Computational Non-Newtonian Hemodynamics of Small Vessels
The significance of non-Newtonian hemodynamics of small blood vessels is addressed via the description and critical discussion of cogent models within Computational Fluid Dynamics (CFD) software, in this case ANSYS-CFX. Several applicable hemodynamical shear-thinning models are presented and the relevance with respect to prediction of Shear Strain Rate (SSR) rigorously examined, in order to critically evaluate salient literature. It is found that the small vessels explored, in line with the aforementioned literature, that non-Newtionian evaluation of the fluid behavior is indeed negligible. The work presented herein is a precursor to investigation of more complex geometries and hemodynamic simulations, which are being actively researched. This is a technical note which attempts to address the significance of Newtonian/non-Newtonian flows in small blood vessels
Prenatal development is linked to bronchial reactivity: epidemiological and animal model evidence
Chronic cardiorespiratory disease is associated with low birthweight suggesting the importance of the developmental environment. Prenatal factors affecting fetal growth are believed important, but the underlying mechanisms are unknown. The influence of developmental programming on bronchial hyperreactivity is investigated in an animal model and evidence for comparable associations is sought in humans. Pregnant Wistar rats were fed either control or protein-restricted diets throughout pregnancy. Bronchoconstrictor responses were recorded from offspring bronchial segments. Morphometric analysis of paraffin-embedded lung sections was conducted. In a human mother-child cohort ultrasound measurements of fetal growth were related to bronchial hyperreactivity, measured at age six years using methacholine. Protein-restricted rats' offspring demonstrated greater bronchoconstriction than controls. Airway structure was not altered. Children with lesser abdominal circumference growth during 11-19 weeks' gestation had greater bronchial hyperreactivity than those with more rapid abdominal growth. Imbalanced maternal nutrition during pregnancy results in offspring bronchial hyperreactivity. Prenatal environmental influences might play a comparable role in humans
Anastomotic complications after tracheal resection: Prognostic factors and management
ObjectiveWe sought to identify risk factors for anastomotic complications after tracheal resection and to describe the management of these patients.MethodsThis was a single-institution, retrospective review of 901 patients who underwent tracheal resection.ResultsThe indications for tracheal resection were postintubation tracheal stenosis in 589 patients, tumor in 208, idiopathic laryngotracheal stenosis in 83, and tracheoesophageal fistula in 21. Anastomotic complications occurred in 81 patients (9%). Eleven patients (1%) died after operation, 6 of anastomotic complications and 5 of other causes (odds ratio 13.0, P = .0001 for risk of death after anastomotic complication). At the end of treatment, 853 patients (95%) had a good result, whereas 37 patients (4%) had an airway maintained by tracheostomy or T-tube. The treatments of patients with an anastomotic complication were as follows: multiple dilations (n = 2), temporary tracheostomy (n = 7), temporary T-tube (n = 16), permanent tracheostomy (n = 14), permanent T-tube (n = 20), and reoperation (n = 16). Stepwise multivariable analysis revealed the following predictors of anastomotic complications: reoperation (odds ratio 3.03, 95% confidence interval 1.69-5.43, P = .002), diabetes (odds ratio 3.32, 95% confidence interval 1.76-6.26, P = .002), lengthy (≥4 cm) resections (odds ratio 2.01, 95% confidence interval 1.21-3.35, P = .007), laryngotracheal resection (odds ratio 1.80, 95% confidence interval 1.07-3.01, P = .03), age 17 years or younger (odds ratio 2.26, 95% confidence interval 1.09-4.68, P = .03), and need for tracheostomy before operation (odds ratio 1.79, 95% confidence interval 1.03-3.14, P = .04).ConclusionsTracheal resection is usually successful and has a low mortality. Anastomotic complications are uncommon, and important risk factors are reoperation, diabetes, lengthy resections, laryngotracheal resections, young age (pediatric patients), and the need for tracheostomy before operation
Telomere length and risk of idiopathic pulmonary fibrosis and chronic obstructive pulmonary disease:a mendelian randomisation study
Background: Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease accounting for 1% of UK deaths. In the familial form of pulmonary fibrosis, causal genes have been identified in about 30% of cases, and a majority of these causal genes are associated with telomere maintenance. Prematurely shortened leukocyte telomere length is associated with IPF and chronic obstructive pulmonary disease (COPD), a disease with similar demographics and shared risk factors. Using mendelian randomisation, we investigated evidence supporting a causal role for short telomeres in IPF and COPD. Methods: Mendelian randomisation inference of telomere length causality was done for IPF (up to 1369 cases) and COPD (13 538 cases) against 435 866 controls of European ancestry in UK Biobank. Polygenic risk scores were calculated and two-sample mendelian randomisation analyses were done using seven genetic variants previously associated with telomere length, with replication analysis in an IPF cohort (2668 cases vs 8591 controls) and COPD cohort (15 256 cases vs 47 936 controls). Findings: In the UK Biobank, a genetically instrumented one-SD shorter telomere length was associated with higher odds of IPF (odds ratio [OR] 4·19, 95% CI 2·33–7·55; p=0·0031) but not COPD (1·07, 0·88–1·30; p=0·51). Similarly, an association was found in the IPF replication cohort (12·3, 5·05–30·1; p=0·0015) and not in the COPD replication cohort (1·04, 0·71–1·53; p=0·83). Meta-analysis of the two-sample mendelian randomisation results provided evidence inferring that shorter telomeres cause IPF (5·81 higher odds of IPF, 95% CI 3·56–9·50; p=2·19 × 10−12). There was no evidence to infer that telomere length caused COPD (OR 1·07, 95% CI 0·90–1·27; p=0·46). Interpretation: Cellular senescence is hypothesised as a major driving force in IPF and COPD; telomere shortening might be a contributory factor in IPF, suggesting divergent mechanisms in COPD. Defining a key role for telomere shortening enables greater focus in telomere-related diagnostics, treatments, and the search for a cure in IPF. Investigation of therapies that improve telomere length is warranted. Funding: Medical Research Council.</p
Telomere length and risk of idiopathic pulmonary fibrosis and chronic obstructive pulmonary disease:a mendelian randomisation study
Lifelong learning and schools as community learning centres : key aspects of a national curriculum draft policy framework for Malta
The island of Malta has been engaged in policy document formulations for curriculum renewal in the country’s educational system (4-16 years of age) since 1988 when the first National Minimum Curriculum (henceforth NMC) was launched (Wain, 1991; Borg et al, 1995). In 1999 a revamped NMC (Ministry of Education, 1999) was developed following a long process of consultation involving various stages and stakeholders. It was a compromise document (Borg & Mayo, 2006) which emerged as a result of reactions to a more radical and coherent draft document produced in 1988.
Both curricular documents were subject to debates and critiques (Wain, 1991; Darmanin, 1993; Borg et al, 1995; Giordmaina, 2000; Borg and Mayo, 2006). More recently a series of volumes providing guidelines, key principles and aims for a national curriculum framework (henceforth NCF) have been produced (MEEF, 2011a,b,c,d) and are currently the target of debate and the focus of reactions by various stakeholders in education including teachers who were asked to read the volumes and provide reactions in the form of answers to a set questionnaire. In this paper, I will focus on one aspect of the documents, the first of its three aims: ‘Learners who are capable of successfully developing their full potential as lifelong learners.’ It is that aspect of the framework documents that falls within the purview of the title for this special issue. The use of this notion attests to the influence of the EU’s policy communications on member states, Malta having joined the Union in 2004 (Mayo, 2007).peer-reviewe
Epidemiological evidence that garden birds are a source of human salmonellosis in England and Wales
The importance of wild bird populations as a reservoir of zoonotic pathogens is well established. Salmonellosis is a frequently diagnosed infectious cause of mortality of garden birds in England and Wales, predominantly caused by Salmonella enterica subspecies enterica serovar Typhimurium definitive phage types 40, 56(v) and 160. In Britain, these phage types are considered highly host-adapted with a high degree of genetic similarity amongst isolates, and in some instances are clonal. Pulsed field gel electrophoresis, however, demonstrated minimal variation amongst matched DT40 and DT56(v) isolates derived from passerine and human incidents of salmonellosis across England in 2000-2007. Also, during the period 1993-2012, similar temporal and spatial trends of infection with these S. Typhimurium phage types occurred in both the British garden bird and human populations; 1.6% of all S. Typhimurium (0.2% of all Salmonella) isolates from humans in England and Wales over the period 2000-2010. These findings support the hypothesis that garden birds act as the primary reservoir of infection for these zoonotic bacteria. Most passerine salmonellosis outbreaks identified occurred at and around feeding stations, which are likely sites of public exposure to sick or dead garden birds and their faeces. We, therefore, advise the public to practise routine personal hygiene measures when feeding wild birds and especially when handling sick wild birds
Application of ring-current theory based on the Johnson-Bovey equation to the aromatic amino acids
Representations of the family in postwar British amateur film: family histories in the Lane and Scrutton collection at the East Anglian Film Archive
This article examines the construction of the postwar British family in amateur film with reference to the Sidney Lane and Cecil Scrutton collection held at the East Anglian Film Archive (EAFA), particularly the films covering 1948 – 1961. Heather Norris Nicholson argues that home movies contribute to 'an understanding of leisure and visual-related practices of consumption as well as the social processes by which people came to give themselves, and others, identities' in the mid-twentieth century (Nicholson, 2004, p. 323). By considering the social and historical contexts in which these home movies were produced, and using accompanying notes by one of the filmmaker’s sons, the leisure time films of Lane and Scrutton can be analysed in order to understand how the amateur cine hobby ideologically constructed family, community and national identity in postwar Britain. The images of Christmas parties, daytrips and holidays in these films reveal much about this particular family, and are therefore very illuminating to the social historian and film scholar of today
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