117 research outputs found
Yeast metabolism in fresh and frozen dough : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, Palmerston North, New Zealand
No full textAuthor also known as SM LovedayFresh bakery products have a very short shelf life, which limits the extent to which manufacturing can be centralised. Frozen doughs are relatively stable and can be manufactured in large volumes, distributed and baked on-demand at the point of sale or consumption. With appropriate formulation and processing a shelf life of several months can be achieved.Shelf life is limited by a decline in proofing rate after thawing, which is attributed to a) the dough losing its ability to retain gas and b) insufficient gas production, i.e. yeast activity. The loss of shelf life is accelerated by delays between mixing and freezing, which allow yeast cells the chance to ferment carbohydrates.This work examined the reasons for insufficient gas production after thawing frozen dough and the effect of pre-freezing fermentation on shelf life. Literature data on yeast metabolite dynamics in fermenting dough were incomplete. In particular there were few data on the accumulation of ethanol, a major fermentation end product which can be injurious to yeast.Doughs were prepared in a domestic breadmaker using compressed yeast from a local manufacturer and analysed for glucose, fructose, sucrose, maltose and ethanol. Gas production after thawing declined within 48 hours of frozen storage. This was accelerated by 30 or 90 minutes of fermentation at 30;C prior to freezing.Sucrose was rapidly hydrolysed and yeast consumed glucose in preference to fructose. Maltose was not consumed while other sugars remained. Ethanol, accumulated from consumption of glucose and fructose, was produced in approximately equal amounts to CO2, indicating that yeast cells metabolised reductively.Glucose uptake in fermenting dough followed simple hyperbolic kinetics and fructose uptake was competitively inhibited by glucose. Mathematical modelling indicated that diffusion of sugars and ethanol in dough occurred quickly enough to eliminate solute gradients brought about by yeast metabolism
Mobile polling and the Aboriginal vote: The federal election
No full textThe study reported in this volume was conducted with the permissions and support of the Australian Electoral Commission and it is published as a report to the Commission. Similar reports on mobile polling in the 1980 and 1983 Northern territory elections - under Territory legislation - have been published in Dean Jaensch and P Loveday, eds, Under One Flag, The 1980 Northern Territory Election (George Allen and Unwin and NARU, 1981) and in P. Loveday and Dean Jaench, eds, A Landslide Election, The NT1983 (NARU, 1984). The arrangement with the Electoral Commission gave NARU observes official status with the polling teams. Detailed preparations for accompanying the polling teams were worked out with Divisional Returning Officers or their deputies in Queensland, the Northern Territory and Western Australia. We wish to acknowledge the unstinting cooperation of David Muffett, Terry Emerson, Brian Howard and Danny Wallace and the general support given by Andrej Cirulis. The careful work of the observers should also be acknowledged: Deborah Wade-Marshall, Raelene Cummings, Rolf Gerritsen, Ciaran O'Faircheallaigh, will Sanders, Wayne Mollah and Scott Cane. And the work of support staff in NARU who prepared the manuscript - Elaine Sommer, Denise Goodfellow and Robyn Darben - is also acknowledged with thanks. The author was also one of the observers and, with help from Deborah Wade-Marshall, coordinator of the observer team
Hiatus or Hidden? The Problem of the Missing Scottish Upland Cursus Monuments
No full textThis paper explores the possibility of cursus monuments being located in upland locations in Britain. These rectangular enclosures date to the Early Neolithic, and are almost all known as cropmark sites in lowland river valley contexts. However, Loveday explores various examples where upland upstanding features such as field banks could have prehistoric origins and easily be misinterpreted. Evidence from three case-study areas in Scotland – Upper Strathearn and Strathtay, Nithsdale, and the Biggar Area – is covered in detail to suggest a context for, and likely location of, possible upland cursus monuments. This is then placed with an upland British context, and the chapter concludes with news of a recent discovery that vindicates the approach of the author.</p
The optimal design for a ground cooling tube in a hot, arid climate
No full textAl-Ajmi developed a TRNSYS model of a ground cooling tube as a PhD project (co-supervised by Hanby and Loveday). Hanby translated the model into Matlab, combined it with an evolution strategy optimization and carried out the search for optimal designs. Hanby was the lead author
How appropriate is it to characterise Western universities as institutionally racist?
No full textThe Macpherson Report in 1999 claimed that public organisations, including universities, were characterised by institutional racism. This paper critically examines the concept of institutional racism before using it as a sensitising concept to investigate ethnographically in one university in the UK over a ten-year period. While I was initially sceptical of the analytical utility of the concept of institutional racism, since it seemed to gloss over important conceptual distinctions, the concept ultimately proved revealing in accounting for significant continuities in the approach of universities, including Midshire, to race equality. Throughout the period under discussion, there was a reluctance to identify race equality as a priority and to take corresponding action because of what has been called "the sheer weight of whiteness" (Back 2004, 1). A comparison of Midshire University with Midshire Police reinforced this perception. While it identified contrasts in the occupational cultures of the two organisations, at the same time it pointed to surprising parallels in their approaches to race equality, which stemmed from a taken for granted white norm. Despite this, the concept of institutional racism as defined in the Macpherson report and employed in the Parekhh report fails to capture significant differences between public organisations and changes over time. The author concludes that universities are not appropriately characterised as institutionally racist and are more appropriately conceptualised as pervaded by a white nor
Mutations in epigenetic regulation genes are a major cause of overgrowth with intellectual disability
No full textTo explore the genetic architecture of human overgrowth syndromes and human growth control, we performed experimental and bioinformatic analyses of 710 individuals with overgrowth (height and/or head circumference ≥+2 SD) and intellectual disability (OGID). We identified a causal mutation in 1 of 14 genes in 50% (353/710). This includes HIST1H1E, encoding histone H1.4, which has not been associated with a developmental disorder previously. The pathogenic HIST1H1E mutations are predicted to result in a product that is less effective in neutralizing negatively charged linker DNA because it has a reduced net charge, and in DNA binding and protein-protein interactions because key residues are truncated. Functional network analyses demonstrated that epigenetic regulation is a prominent biological process dysregulated in individuals with OGID. Mutations in six epigenetic regulation genes—NSD1, EZH2, DNMT3A, CHD8, HIST1H1E, and EED—accounted for 44% of individuals (311/710). There was significant overlap between the 14 genes involved in OGID and 611 genes in regions identified in GWASs to be associated with height (p = 6.84 × 10−8), suggesting that a common variation impacting function of genes involved in OGID influences height at a population level. Increased cellular growth is a hallmark of cancer and there was striking overlap between the genes involved in OGID and 260 somatically mutated cancer driver genes (p = 1.75 × 10−14). However, the mutation spectra of genes involved in OGID and cancer differ, suggesting complex genotype-phenotype relationships. These data reveal insights into the genetic control of human growth and demonstrate that exome sequencing in OGID has a high diagnostic yield
Runs of homozygosity and testicular cancer risk.
No full textBACKGROUND: Testicular germ cell tumour (TGCT) is highly heritable but > 50% of the genetic risk remains unexplained. Epidemiological observation of greater relative risk to brothers of men with TGCT compared to sons has long alluded to recessively acting TGCT genetic susceptibility factors, but to date none have been reported. Runs of homozygosity (RoH) are a signature indicating underlying recessively acting alleles and have been associated with increased risk of other cancer types. OBJECTIVE: To examine whether RoH are associated with TGCT risk. METHODS: We performed a genome-wide RoH analysis using GWAS data from 3206 TGCT cases and 7422 controls uniformly genotyped using the OncoArray platform. RESULTS: Global measures of homozygosity were not significantly different between cases and controls, and the frequency of individual consensus RoH was not significantly different between cases and controls, after correction for multiple testing. RoH at three regions, 11p13-11p14.3, 5q14.1-5q22.3 and 13q14.11-13q.14.13, were, however, nominally statistically significant at p < 0.01. Intriguingly, RoH200 at 11p13-11p14.3 encompasses Wilms tumour 1 (WT1), a recognized cancer susceptibility gene with roles in sex determination and developmental transcriptional regulation, processes repeatedly implicated in TGCT aetiology. DISCUSSION AND CONCLUSION: Overall, our data do not support a major role in the risk of TGCT for recessively acting alleles acting through homozygosity, as measured by RoH in outbred populations of cases and controls
Galaxy and mass assembly (GAMA) : AUTOZ spectral redshift measurements, confidence and errors
No full textThe Galaxy And Mass Assembly (GAMA) survey has obtained spectra of over 230 000 targets using the Anglo-Australian Telescope. To homogenize the redshift measurements and improve the reliability, a fully automatic redshift code was developed (AUTOZ). The measurements were made using a cross-correlation method for both the absorption-and the emission-line spectra. Large deviations in the high-pass-filtered spectra are partially clipped in order to be robust against uncorrected artefacts and to reduce the weight given to single-line matches. A single figure of merit (FOM) was developed that puts all template matches on to a similar confidence scale. The redshift confidence as a function of the FOM was fitted with a tanh function using a maximum likelihood method applied to repeat observations of targets. The method could be adapted to provide robust automatic redshifts for other large galaxy redshift surveys. For the GAMA survey, there was a substantial improvement in the reliability of assigned redshifts and in the lowering of redshift uncertainties with a median velocity uncertainty of 33 kms-1.Peer reviewe
Optimal design of a piezoelectric transducer for exciting guided wave ultrasound in rails
No full textAn existing Ultrasonic Broken Rail Detection System [1] installed in South Africa on a heavy duty railway line is currently being upgraded to include defect detection and location. To accomplish this, an ultrasonic piezoelectric transducer to strongly excite a guided wave mode with energy concentrated in the web (web mode) of a rail is required. A previous study [2] demonstrated that the recently developed SAFE-3D (Semi-Analytical Finite Element – 3 Dimensional) method can effectively predict the guided waves excited by a resonant piezoelectric transducer. In this study, the SAFE-3D model is used in the design optimization of a rail web transducer. A bound-constrained optimization problem was formulated to maximize the energy transmitted by the transducer in the web mode when driven by a pre-defined excitation signal. Dimensions of the transducer components were selected as the three design variables. A Latin hypercube sampled design of experiments that required a total of 500 SAFE- 3D analyses in the design space was employed in a response surface-based optimization approach. The Nelder-Mead optimization algorithm was then used to find an optimal transducer design on the constructed response surface. The radial basis function response surface was first verified by comparing a number of predicted responses against the computed SAFE-3D responses. The performance of the optimal transducer predicted by the optimization algorithm on the response surface was also verified to be sufficiently accurate using SAFE-3D. The computational advantages of SAFE-3D in transducer design is noteworthy given we needed to conduct more than 500 analyses. The optimal design was then manufactured and experimental measurements were used to validate the predicted performance. The adopted design method has demonstrated the capability to automate the design of transducers for a particular rail cross- section and frequency range.</p
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