1,051 research outputs found

    Dry weight model, capacitance and metabolic data as indicators of fungal biomass growth in solid state fermentation

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    Developing improved industrial bioprocesses has been a driver for the growing research attention to solid state fermentation, in particular involving filamentous fungi. Accurate description of fungal growth in these systems is crucial and certainly needed to enable optimal deployment of subsequent engineering work. This manuscript proposes a model based on total dry weight measurement to describe biomass growth for Aspergillus awamori on wheat grains in two systems: Petri dishes and a 1L packed bed bioreactor. The proposed dry weight model can be used not only for identifying growth phases of the fungus but also to calculate key growth parameters such as specific growth rate and maximum biomass concentration. The use of techniques based on capacitance measurements and on metabolic data were also used in order to estimate fungal growth and to validate the proposed model

    Experimentation and self learning in continuous database marketing

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    We present a method for continuous database marketing that identifies target customers for a number of marketing offers using predictive models. The algorithm then selects the appropriate offer for the customer. Experimental design principles are encapsulated to capture more information that will be used to monitor and refine the predictive models. The updated predictive models are then used for the next round of marketing offers.<br /

    Concomitant HIV infection in newly diagnosed multiple myeloma patients is hard to recognise and should be tested for routinely in areas of high endemicity

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    Background. Over the past three decades much has changed in the treatment and outcomes of patients suffering concurrently from both multiple myeloma (MM) and HIV. While the prevalence of MM appears to be higher in HIV-positive individuals than in those who are uninfected, early recognition of patients suffering from both diseases is difficult and little information is available on their demographics and clinical presentation.Objective. To compare the presenting features of HIV-positive patients diagnosed with MM with those of HIV-negative patients.Methods. A single-centre, retrospective cohort study included 16 HIV-positive and 73 HIV-negative patients diagnosed with MM, in order to compare variables related to the clinical presentation of both conditions.Results. HIV-positive patients presented with MM at a significantly younger age, and had fewer osteolytic lesions, less renal impairment and lower neutrophil counts. Disease stage, gender, pathological fractures, bone marrow plasmacytosis, plasmacytomas and lymphocyte counts were comparable, emphasising the difficulty of identifying these patients. The HIV-positive patients had relatively high CD4 counts and a low prevalence of abnormal Freelite kappa/lambda ratios. All HIV-positive patients presented with paraproteins of the immunoglobulin G (IgG) type, implying a possible relationship between MM and an IgG response to HIV antigens.Conclusions. On the basis of our findings and literature on the treatment of both diseases, we suggest that HIV be tested for routinely in younger MM patients, especially in areas with a high prevalence of HIV. The integration of our results into the sparse knowledge on the role of HIV infection-related MM provides possible new insights into the interaction between these diseases

    An integrated approach for analysing and assessing the performance of virtual learning groups

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    Collaborative distance learning involves a variety of elements and factors that have to be considered and measured in order to analyse and assess group and individual performance more effectively and objectively. This paper presents an approach that integrates qualitative, social network analysis (SNA) and quantitative techniques for evaluating online collaborative learning interactions. Integration of various different data sources, tools and techniques provides a more complete and robust framework for group modelling and guarantees a more efficient evaluation of group effectiveness and individual competence. Our research relies on the analysis of a real, long-term, complex collaborative experience, which is initially evaluated in terms of principled criteria and a basic qualitative process. At the end of the experience, the coded student interactions are further analysed through the SNA technique to assess participatory aspects, identify the most effective groups and the most prominent actors. Finally, the approach is contrasted and completed through a statistical technique which sheds more light on the results obtained that far. The proposal draws a well-founded line toward the development of a principled framework for the monitoring and analysis of group interaction and group scaffolding which can be considered a major issue towards the actual application of the CSCL proposals to real classrooms.Peer ReviewedPostprint (author's final draft

    'Reclaiming the criminal' : the role and training of prison officers in England, 1877-1914

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    This article examines the role and training of prison officers in England, between 1877 and 1914. It is concerned with the changing penal philosophies and practices of this period and how these were implemented in local prisons, and the duties of the prison officer. More broadly, this article argues that the role of the prison officer and their training (from 1896) reflect wider ambiguities in prison policy and practice during this period

    Periodic harmonic functions on lattices and points count in positive characteristic

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    This survey addresses pluri-periodic harmonic functions on lattices with values in a positive characteristic field. We mention, as a motivation, the game "Lights Out" following the work of Sutner, Goldwasser-Klostermeyer-Ware, Barua-Ramakrishnan-Sarkar, Hunzikel-Machiavello-Park e.a.; see also 2 previous author's preprints for a more detailed account. Our approach explores harmonic analysis and algebraic geometry over a positive characteristic field. The Fourier transform allows us to interpret pluri-periods of harmonic functions on lattices as torsion multi-orders of points on the corresponding affine algebraic variety.Comment: These are notes on 13p. based on a talk presented during the meeting "Analysis on Graphs and Fractals", the Cardiff University, 29 May-2 June 2007 (a sattelite meeting of the programme "Analysis on Graphs and its Applications" at the Isaac Newton Institute from 8 January to 29 June 2007

    Electron Dephasing in Mesoscopic Metal Wires

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    The low-temperature behavior of the electron phase coherence time, τϕ\tau_{\phi}, in mesoscopic metal wires has been a subject of controversy recently. Whereas theory predicts that τϕ(T)\tau_{\phi}(T) in narrow wires should increase as T−2/3T^{-2/3} as the temperature TT is lowered, many samples exhibit a saturation of τϕ\tau_{\phi} below about 1 K. We review here the experiments we have performed recently to address this issue. In particular we emphasize that in sufficiently pure Ag and Au samples we observe no saturation of τϕ\tau_{\phi} down to our base temperature of 40 mK. In addition, the measured magnitude of τϕ\tau_{\phi} is in excellent quantitative agreement with the prediction of the perturbative theory of Altshuler, Aronov and Khmelnitskii. We discuss possible explanations why saturation of τϕ\tau_{\phi} is observed in many other samples measured in our laboratory and elsewhere, and answer the criticisms raised recently by Mohanty and Webb regarding our work.Comment: 14 pages, 3 figures; to appear in proceedings of conference "Fundamental Problems of Mesoscopic Physics", Granada, Spain, 6-11 September, 200

    SO(10) unified models and soft leptogenesis

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    Motivated by the fact that, in some realistic models combining SO(10) GUTs and flavour symmetries, it is not possible to achieve the required baryon asymmetry through the CP asymmetry generated in the decay of right-handed neutrinos, we take a fresh look on how deep this connection is in SO(10). The common characteristics of these models are that they use the see-saw with right-handed neutrinos, predict a normal hierarchy of masses for the neutrinos observed in oscillating experiments and in the basis where the right-handed Majorana mass is diagonal, the charged lepton mixings are tiny. In addition these models link the up-quark Yukawa matrix to the neutrino Yukawa matrix Y^\nu with the special feature of Y^\nu_{11}-> 0 Using this condition, we find that the required baryon asymmetry of the Universe can be explained by the soft leptogenesis using the soft B parameter of the second lightest right-handed neutrino whose mass turns out to be around 10^8 GeV. It is pointed out that a natural way to do so is to use no-scale supergravity where the value of B ~1 GeV is set through gauge-loop corrections.Comment: 26 pages, 2 figures. Added references, new appendix of a relevant fit and improved comment
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