3,981 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
Recall of random and distorted positions: Implications for the theory of expertise.
No full textThis paper explores the question, important to the theory of expert performance, of the nature and number of chunks that chess experts hold in memory. It examines how memory contents determine players' abilities to reconstruct (a) positions from games, (b) positions distorted in various ways and (c) and random positions. Comparison of a computer simulation with a human experiment supports the usual estimate that chess Masters store some 50,000 chunks in memory. The observed impairment of recall when positions are modified by mirror image reflection, implies that each chunk represents a specific pattern of pieces in a specific location. A good account of the results of the experiments is given by the template theory proposed by Gobet and Simon (in press) as an extension of Chase and Simon's (1973a) initial chunking proposal, and in agreement with other recent proposals for modification of the chunking theory (Richman, Staszewski & Simon, 1995) as applied to various recall tasks
The beginnings of behavioral economics : Katona, Simon, and Leibenstein's X-efficiency theory /
No full text1. Introduction2. Two beginnings3. The "Big 3.#x94; Simon, Katona, Leibenstein4. It didn't just happen overnight5. Leibenstein before X-efficiency theory6. X-efficiency. An intervening variable7. Empirical research on XE: c.1967-19908. XE among US financial institutions9. XE among financial firms in Asia10. XE among Asian non-financial institutions11. XE in Europe12. XE in Australia and New Zealand, Latin America, the Middle East, Africa, and the world13. ConclusionsDescription based on CIP data; resource not viewed.Elsevie
A born-digital author lexicon for 17th c. French: Sévigné’s case
No full textPreparing an edition of Madame de Sévigné’s correspondance encoded in TEI, we are currently facing two problems. First, while French medievalists have a long experience of establishing lexicons, specialists of 17th c. French literature traditionally do not provide such a study in their editions. Second, we are not aware of any born-digital author lexicon in TEI for (17th c.) French language. We therefore have to tackle two problems at the same time, and create both a scientific methodology, a..
A born-digital author lexicon for 17th c. French: Sévigné’s case
No full textPreparing an edition of Madame de Sévigné’s correspondance encoded in TEI, we are currently facing two problems. First, while French medievalists have a long experience of establishing lexicons, specialists of 17th c. French literature traditionally do not provide such a study in their editions. Second, we are not aware of any born-digital author lexicon in TEI for (17th c.) French language. We therefore have to tackle two problems at the same time, and create both a scientific methodology, a..
Tetragonal Almandine-Pyrope Phase, TAPP: Finally a name for it, the new mineral jeffbenite
No full textJeffbenite, ideally Mg3Al2Si3O8, previously known as tetragonal-almandine-pyrope-phase ('TAPP’), has been characterized as a new mineral from an inclusion in an alluvial diamond from São Luiz river, Juina district of Mato Grosso, Brazil. Its density is 3.576 g/cm3 and its microhardness is ∼7. Jeffbenite is uniaxial (-) with refractive indexes ω = 1.733(5) and ε = 1.721 (5). The crystals are in general transparent emerald green.
Its approximate chemical formula is (Mg262Fe2+0.27)(Al186Cr016)(Si2 g2Al018)O12 with very minor amounts of Mn, Na and Ca. Laser ablation ICP-MS showed that jeffbenite has a very low concentration of trace elements. Jeffbenite is tetragonal with space group I42d, cell edges being a = 6.5231(1) and c = 18.1756(3) Å. The main diffraction lines of the powder diagram are [d (in Å), intensity, hkl]: 2.647, 100, 2 0 4; 1.625, 44, 3 2 5; 2.881, 24, 2 1 1; 2.220, 19, 2 0 6; 1.390, 13, 4 2 4; 3.069, 11,2 0 2; 2.056, 11,2 2 4; 1.372, 11,2 0 12.
The structural formula of jeffbenite can be written as (M1)(M2)2(M3)2(T1)(T2)2O12 with M1 dominated by Mg, M2 dominated by Al, M3 dominated again by Mg and both T1 and T2 almost fully occupied by Si. The two tetrahedra do not share any oxygen with each other (i.e. jeffbenite is classified as an orthosilicate).
Jeffbenite was approved as a new mineral by the IMA Commission on New Minerals and Mineral Names with the code IMA 2014-097. Its name is after Jeffrey W. Harris and Ben Harte, two world-leading scientists in diamond research. The petrological importance of jeffbenite is related to its very deep origin, which may allow its use as a pressure marker for detecting super-deep diamonds. Previous experimental work carried out on a Ti-rich jeffbenite establishes that it can be formed at 13 GPa and 1700 K as maximum P-T conditions
Forecasting banknotes
No full textA central bank’s liquidity forecast is important in ensuring that it supplies the banking system’s need for central bank money. Banknote (or currency in circulation) demand is the largest and for some central banks the most variable component of the liquidity forecast. Accurate forecasting of banknotes is essential in ensuring an accurate liquidity forecast and in turn effective monetary policy implementation. This Handbook discusses these issues and outlines a structural time series state space (STSSS) model which is now used by central banks including the Bank of England and ECB to forecast banknotes (currency in circulation).Forecasting banknotes
FONDUE-FR-PRINT-16 - Transcriptions of French 16th c. prints
No full text<p>HTR Groundtruth for French 16th c. prints, produced with <a href="https://github.com/mittagessen/kraken">Kraken</a> and <a href="https://gitlab.com/scripta/escriptorium">eScriptorium</a>.</p>
<p>Original data is available on <a href="https://github.com/FoNDUE-HTR/FONDUE-FR-PRINT-16">GitHub</a>.</p><pre>@misc{FONDUE_FR_PRINT_16,
author = {Gabay, Simon},
title = {FONDUE-FR-PRINT-16},
year = {2024},<br> publisher={Zenodo}<br> url={<a href="../doi/10.5281/zenodo.11526149">https://zenodo.org/doi/10.5281/zenodo.11526149</a>}<br> doi={<a href="../doi/10.5281/zenodo.11526149">10.5281/zenodo.11526149</a>}<br>}</pre>
Susceptibility of Enterovirus B strains to disinfectants and heat
No full textThe susceptibility of waterborne viruses to different inactivating treatments is acknowledged to vary between viruses and even between closely related strains, yet the extent of this variation, or the underlying mechanisms, are not known. Here, different enteroviruses (six strains of coxsackievirus B5 (CVB5), two strains of coxsackievirus B4 (CVB4) and one strain of coxackievirus B1 (CVB1)) were isolated from wastewater. The different viruses were then exposed to disinfectants used in water and wastewater treatment (UV254, free chlorine (FC), chlorine dioxide (ClO2)) and to stressors encountered in the environment (sunlight, temperature). Inactivation kinetics of the environmental isolates were compared with those of laboratory enterovirus strains (CVB5 Faulkner and echovirus 11 Gregory) and MS2 bacteriophage. FC exhibited the greatest variability in inactivation kinetics between different strains, whereas inactivation by UV254 differed only subtly. The variability in inactivation kinetics was greater between serotypes than it was among the seven strains of the CVB5 serotype. MS2 was a conservative surrogate of enterovirus inactivation by UV254, sunlight or heat, but frequently underestimated the disinfection requirements for FC and ClO2.
To assess the mechanisms underlying the differing susceptibilities of these viruses to inactivation, we focused on thermal inactivation. Specifically, we extensively analyzed the inactivation of these viruses at 30 and 55°C, and under different conditions of pH and NaCl concentrations. At 30°C, inactivation at neutral pH was slow, but both acidic and alkaline pH enhanced inactivation, and the addition of 1 M NaCl exerted a synergistic inactivating effect. These findings are consistent with RNA cleavage being the main mechanism of inactivation, and genome degradation was experimentally confirmed. At 55°C, salt had a protective effect on all viruses. This was rationalized by calculations of the different protein interaction forces, which demonstrated that increasing concentrations of salt resulted in increasing attractive forces at the capsid pentamer interfaces. At this temperature, major differences in thermoresistance between the viruses were observed, with CVB4 and E11 displaying the lowest thermoresistance, and the CVB5 laboratory strain being less thermoresistant than the CVB5 isolates. These differences could not be explained by a shift in capsid pentamer interaction forces, but likely resulted from mutations located in VP1 pocket region.
The importance of the VP1 pocket region was further confirmed by adapting CVB5 to two different temperatures (50 and 55 °C). The thermo-adapted strains exhibited a competitive fitness trade-off compared to control strains, but were significantly more resistant to thermal inactivation. This resistance coincided with the appearance of one or several of four mutations in the VP1 region of the structural proteins. These mutations did not affect the interaction forces at the pentamer interface. Instead, they were located in the VP1 pocket region, confirming the importance of this region in the acquisition of thermotolerance. Overall, these data indicate that the thermostability of a virus can be enhanced by external (matrix) factors, in particular salinity, or by intrinsic (structural) modifications in the VP1 pocket region.LE
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