Computer modelling of high temperature air combustion

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.High Temperature Air Combustion, HiTAC, is an innovative combustion technology which offers improved heat transfer and a reduction in fuel consumption and NOx emissions. This paper describes a project in which a computational fluid dynamic model of a furnace working on high temperature air combustion technology was developed using FLUENT® CFD software. The model was validated against experimental data obtained from KTH in Sweden. The predicted results compared very well with this experimental data, and were also closer than the predictions from the model built by KTH. The model was applied to a steam boiler of Malta’s Delimara Power Station. Two scenarios were considered: the boiler with conventional combustion and the boiler converted to HITAC. To reduce computational time, a 400:1 scaled down version of the boiler was modelled based on NOx scaling. Further reductions were made by taking advantage of the symmetry of the boiler and by obtaining the solution for a single burner, and then prescribing the parameter profiles for the single burner to the full boiler model as boundary conditions. The computer model results showed much lower NOx emission levels when firing the boiler with methane compared to heavy fuel oil. Further reductions in NOx emissions were obtained with HITAC technology and using methane as a fuel.dc201

Common variants of the TCF7L2 gene are associated with increased risk of type 2 diabetes mellitus in a UK-resident South Asian population

Background Recent studies have implicated variants of the transcription factor 7-like 2 (TCF7L2) gene in genetic susceptibility to type 2 diabetes mellitus in several different populations. The aim of this study was to determine whether variants of this gene are also risk factors for type 2 diabetes development in a UK-resident South Asian cohort of Punjabi ancestry. Methods We genotyped four single nucleotide polymorphisms (SNPs) of TCF7L2 (rs7901695, rs7903146, rs11196205 and rs12255372) in 831 subjects with diabetes and 437 control subjects. Results The minor allele of each variant was significantly associated with type 2 diabetes; the greatest risk of developing the disease was conferred by rs7903146, with an allelic odds ratio (OR) of 1.31 (95% CI: 1.11 – 1.56, p = 1.96 × 10-3). For each variant, disease risk associated with homozygosity for the minor allele was greater than that for heterozygotes, with the exception of rs12255372. To determine the effect on the observed associations of including young control subjects in our data set, we reanalysed the data using subsets of the control group defined by different minimum age thresholds. Increasing the minimum age of our control subjects resulted in a corresponding increase in OR for all variants of the gene (p ≤ 1.04 × 10-7). Conclusion Our results support recent findings that TCF7L2 is an important genetic risk factor for the development of type 2 diabetes in multiple ethnic groups

‘Left behind places’: a geographical etymology

‘Left behind places’ has become the leitmotif of geographical inequalities since the 2008 crisis. Yet, the term’s origins, definition and implications are poorly specified and risk obscuring the differentiated problems and pathways of different kinds of areas. This paper explicates the geographical etymology and spatial imaginary of ‘left behind places’. It argues that the appellation and its spatial expression have modified how geographical inequalities are understood and addressed by recovering a more relational understanding of multiple ‘left behind’ conditions, widening the analytical frame beyond only economic concerns, and opening up interpretations of the ‘development’ of ‘left behind places’ and their predicaments and prospects. While renewing interest in fundamental urban and regional concerns, what needs to endure from the ascendance of the ‘left behind places’ label is the terminology and spatial imaginary of reducing geographical inequalities and enhancing social and spatial justice

Impact of COVID-19 pandemic on eye cancer care in United Kingdom

The COVID-19 pandemic has had an unprecedented impact on the National Health Service in United Kingdom. The UK Ocular Oncology Services evaluated the impact on the adult eye cancer care in the UK. All four adult Ocular Oncology centres participated in a multicentre retrospective review comparing uveal melanoma referral patterns and treatments in a 4-month period during the national lockdown and first wave of the COVID-19 pandemic in 2020 with corresponding periods in previous 2 years. During the national lockdown, referral numbers and confirmed uveal melanoma cases reduced considerably, equalling to ~120 fewer diagnosed uveal melanoma cases compared to previous 2 years. Contrary to the recent trend, increased caseloads of enucleation and stereotactic radiosurgery (p > 0.05), in comparison to fewer proton beam therapy (p < 0.05), were performed. In the 4-month period following lockdown, there was a surge in clinical activities with more advanced diseases (p < 0.05) presenting to the services. As the COVID-19 pandemic continues to mount pressure and reveal its hidden impact on the eye cancer care, it is imperative for the Ocular Oncology Services to plan recovery strategies and innovative ways of working

The transcription factor 7-like 2 (TCF7L2) polymorphism may be associated with focal arteriolar narrowing in Caucasians with hypertension or without diabetes: the ARIC Study

<p>Abstract</p> <p>Background</p> <p>Transcription factor 7-like 2 (<it>TCF7L2</it>) has emerged as a consistently replicated susceptibility gene for type 2 diabetes, however, whether the <it>TCF7L2 </it>gene also has similar effects on the retinal microvasculature is less clear. We therefore aimed to investigate the association between the transcription factor 7-like 2 (<it>TCF7L2</it>) rs7903146 polymorphism and retinal microvascular phenotypes in the Atherosclerosis Risk in Communities (ARIC) Study (1993-1995).</p> <p>Methods</p> <p>This was a population-based, cross-sectional study of 10,320 middle-aged African American (n = 2,199) and Caucasian (n = 8,121) men and women selected from four United States communities to examine the association between <it>TCF7L2 </it>rs7903146 polymorphism and retinal microvascular signs (retinopathy, focal arteriolar narrowing, arteriovenous nicking, arteriolar and venular calibers). Photographs on one randomly selected eye were graded for presence of retinal microvascular signs and used to measure retinal vessel calibres.</p> <p>Results</p> <p>After adjusting for age, sex, study center, mean arterial blood pressure, total serum cholesterol, triglycerides, and other covariates, few associations of <it>TCF7L2 </it>rs7903146 and retinal microvascular signs were noted. <it>TCF7L2 </it>rs7903146 T risk allele was significantly associated with focal arteriolar narrowing in Caucasians with hypertension [odds ratio (OR)_{CT vs. CC}(95% CI) = 1.25 (1.09-1.44); OR_{TT vs. CC}= 1.56 (1.18-2.06); <it>P </it>= 0.002] and in Caucasians without diabetes [OR _{CT vs. CC}= 1.18 (1.06-1.32); OR _{TT vs. CC}= 1.40 (1.12, 1.75); <it>P </it>= 0.003]. No significant association of the <it>TCF7L2 </it>rs7903146 polymorphism and retinal vascular signs was noted among African American individuals.</p> <p>Conclusions</p> <p><it>TCF7L2 </it>rs7903146 is not consistently associated with retinal microvascular signs. However, we report an association between the <it>TCF7L2 </it>rs7903146 polymorphism and focal arteriolar narrowing in Caucasians with hypertension or without diabetes. Further research in other large, population-based studies is needed to replicate these findings.</p

No association between a candidate TCF7L2 variant and risk of breast or ovarian cancer

<p>Abstract</p> <p>Background</p> <p>TCF7L2 is a transcription factor involved in Wnt/β-catenin signaling which has a variant known to be associated with risk of Type 2 diabetes and, in some studies, with risk of certain cancers, including familial breast cancer. No studies of ovarian cancer have been reported to date.</p> <p>Methods</p> <p>Two clinic-based case-control studies at the Mayo Clinic were assessed including 798 breast cancer cases, 843 breast cancer controls, 391 ovarian cancer cases, and 458 ovarian cancer controls. Genotyping at <it>TCF7L2 </it>rs12255372 used a 5' endonuclease assay, and statistical analysis used logistic regression among participants as a whole and among <it>a priori</it>-defined subsets.</p> <p>Results</p> <p>No associations with risk of breast or ovarian cancer were observed (ordinal model, p = 0.62 and p = 0.75, respectively). In addition, no associations were observed among sub-groups defined by age, BMI, family history, stage, grade, histology, or tumor behavior.</p> <p>Conclusion</p> <p>Although the biology of the Wnt/β-catenin signaling pathway and prior association between rs12255372 and numerous phenotypes warranted examination of this <it>TCF7L2 </it>SNP, no compelling evidence for association with breast or ovarian cancer was observed.</p

Comparison of GC‐MS, HPLC‐MS and SIFT‐MS in conjunction with multivariate classification for the diagnosis of Crohn’s disease in urine

The developed world has seen an alarming increase in the incidence of gastrointestinal diseases, among the most common of which is Crohn’s disease (CD) in the young. The current “gold standard” techniques for diagnosis are often costly, time consuming, inefficient, invasive, and offer poor sensitivities and specificities. This paper compares the performances of three hyphenated instrumental techniques that have been suggested as rapid methods for the non‐invasive diagnosis of CD from urine. These techniques are gas chromatography‐mass spectrometry (GC‐MS), high performance liquid chromatography‐mass spectrometry (HPLC‐MS) and selected ion flow tube mass spectrometry (SIFT‐MS). Each of these techniques is followed by multivariate classification to provide a diagnosis based on the acquired data. The most promising results for potentially diagnosing CD was via HPLC‐MS. An overall classification accuracy of 73% (74% specificity; 73% sensitivity) was achieved for differentiating CD from healthy controls, statistically significant at 95% confidence