9,633 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
Noise considerations when determining phase of large-signal microwave measurements
No full textAdvances in microwave instrumentation now make it feasible to accurately measure not only the magnitude spectrum, but also the phase spectrum of wide-bandwidth signals. In a practical measurement, the spectrum is measured over a finite window of time. The phase spectrum is related to the position of this window, causing the spectrum to differ between measurements of an identical waveform. It is difficult to compare multiple measurements with different window positions or to incorporate them into a model. Several methods have been proposed for determining the phase spectrum such that multiple measurements can be effectively compared and utilized in models. The methods are reviewed in terms of the information required to determine the phase and compared in terms of their robustness in the presence of measurement noise
The random component of mixer-based nonlinear vector network analyzer measurement uncertainty
No full textThe uncertainty, due to random noise, of the measurements made with a mixer-based nonlinear vector network analyzer are analyzed. An approximate covariance matrix corresponding to the measurements is derived that can be used for fitting models and maximizing the dynamic range in the measurement setup. The validity of the approximation is verified with measurements
Converting SrI <sub>2</sub> :Eu <sup>2+</sup> into a near infrared scintillator by Sm <sup>2+</sup> co-doping
No full text The luminescence and scintillation properties of SrI 2 single crystals doped with 5% Eu 2+ and 0.05%, 0.2% and 0.5% Sm 2+ are evaluated. X-ray excited and photoluminescence measurements show energy transfer from excited Eu 2+ ions to Sm 2+ ions. At a concentration of 0.5% Sm 2+ , the luminescence consists almost entirely of 740 nm emission from Sm 2+ 5d-4f transitions. Co-doping SrI 2 :5% Eu 2+ with Sm 2+ provides a novel method to bypass the self-absorption problem encountered in large SrI 2 :Eu 2+ crystals and, at the same time, provides a unique near-infrared emitting scintillator with a light yield of approximately 40,000 photons/MeV. Accepted Author ManuscriptRST/Fundamental Aspects of Materials and EnergyRST/Luminescence Material
'Laws 'Needefull in Later to be Abrogated': Intersex and the Sources of Christian Theology
No full textThis is the author accepted manuscript. The final version is available from Palgrave Macmillan via the DOI in this record
Introduction: Troubling Bodies?
No full textThis is the author accepted manuscript. The final version is available from Palgrave Macmillan via the DOI in this record
Group, possibly including Bob Scott and Neil Hall, climbing Monitor Rock using ropes,1942
No full textWritten on verso: Bob Scott 151 Neil Hall SM. 1942.
PH Coll 1408.29
Average SM Score per Application.
No full textAverage SM score for each application versus the rank order by average SM score, with error bars representing standard error (2009–2012).</p
Differential Diagnoses of Systemic Mastocytosis in Routinely Processed Bone Marrow Biopsy Specimens: A Review
No full textDiagnosis of systemic mastocytosis (SM) is mainly based on the morphological demonstration of compact mast cell infiltrates in various tissue sites. In almost all patients such infiltrates are detected in the bone marrow. Reliable immunohistochemical markers for the diagnosis and grading of SM have been established, but various differential diagnoses including myeloproliferative neoplasms, basophilic and eosinophilic leukemias may be very difficult to delineate. Even more challenging is the recognition of hematological neoplasms with signs of mast cell differentiation but not fulfilling diagnostic criteria for SM, especially the rare myelomastocytic leukemia. It is also important to separate the reactive state of mast cell hyperplasia from indolent variants of SM, especially those with a very low degree of bone marrow infiltration and absence of compact mast cell infiltrates. When the lymphocytic component of the SM infiltrate is very prominent, SM may be confused with an indolent lymphoma, especially lymphoplasmacytic lymphoma which almost always shows a marked reactive increase in mast cells. In aggressive and leukemic variants of SM, mast cells may be very atypical and devoid of metachromatic granules. This hypogranulation can be regarded as cellular atypia and may lead to the misdiagnosis aspect of monocytic leukemia or histiocytic neoplasm. Regarding immunohistochemical anomalies, mast cells in aggressive and leukemic SM have been found to express CD30 (Ki1-antigen). Thus, anaplastic large cell lymphoma or Hodgkin's disease may first be considered rather than SM. There is increasing evidence that most patients with long-standing adult-type urticaria pigmentosalike skin lesions have in fact indolent SM. Therefore, such skin lesions are an important clue to the correct diagnosis in these patients. However, in aggressive or leukemic SM skin lesions are usually absent and then the correct diagnosis relies on an appropriate investigation of bone marrow biopsy specimens using both SM-related immunohistochemical markers (tryptase, KIT, CD25, CD30) but also markers excluding potential differential diagnoses. Investigation for presence of the activating KIT point mutation D816V is very helpful to establish a correct diagnosis of SM in all the difficult cases exhibiting a low degree of bone marrow infiltration or puzzling morphological findings. Copyright (C) 2010 S. Karger AG, Base
Intrafullerene electron transfers in Sm-containing metallofullerenes: Sm@C-2n (74 <= 2n <= 84)
No full textThe electronic properties of Sm-containing metallofullerenes, Sm@C-74, Sm@C-76 (I, II), Sm@C-78, Sm@C-80, Sm@C-82 (I, II, III) and Sm@C-84 (I, II, III), are characterized by UV-Vis-NIR absorption spectroscopy and electron energy-loss spectroscopy (EELS). the UV-Vis-NIR absorption spectra of Sm@C-74, Sm@C-80, Sm@C-82 (I, II, III) and Sm@C-84 (I, II) are quite similar to those of the corresponding Ca, Sr, Ba, Eu, Tm, Yb-based metallofullerenes. In contrast, the absorption spectra of Sm@C-76 (I, II), Sm@C-78 and Sm@C-84(III) show a novel feature: the onset for Sm@C-78 is observed similar to 2600 nm, which corresponds to a small band gap (similar to0.5 eV). Furthermore, the oxidation states of Sm atom in the various fullerene cages are investigated by EELS, which reveals that the Sm atom takes +2 oxidation state in the fullerene cages. A probable rationale for the tendency to have the Sm2+ state is presented based on a simple thermochemical cycle model. (C) 2001 by Elsevier Science Inc.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000168906500014&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Biochemical Research MethodsBiochemistry & Molecular BiologyComputer Science, Interdisciplinary ApplicationsCrystallographyMathematical & Computational BiologySCI(E)EI30ARTICLE2244-2511
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