14,641 research outputs found

    Lautman and the Reality of Mathematics

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    Working in he 1930s, Albert Lautman described with extraordinary clarity the new understanding of mathematics of that time. He delighted in the multiple manifestations of a common idea in different mathematical fields. However, he took the common idea to belong not to mathematics itself, but to an 'ideal reality' sitting above mathematics. I argue in this paper that now that we have a mathematical language which can characterize these common ideas, we need not follow Lautman to adopt his form of Platonism. On the other hand, Lautman should be much better known than he is for pointing philosophy towards this most important feature of mathematics

    DNA homology within the Rhizobiaceae : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Microbiology at Massey University

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    The relationship of rhizobia that nodulate Galega officinalis to the known species of Rhizobium and Bradyrhizobium was investigated. Similarly, the recently discovered fast­ growing soybean nodulating group of rhizobia was studied. Both groups were investigated using DNA:DNA hybridization as well as nodulation on legumes and phage-typing. The Galega nodulating rhizobia were found to form a distinct DNA homology group. The mean relative homology of 11 strains of Galega nodulating rhizobia with the reference strains gal 1 and gal NW 3, which effectively nodulate Galega officinalis, was significantly higher than the mean relative homology of other groups of rhizobia. The Galega rhizobia only nodulated Galega officinalis and formed a distinct phage-typing group in agreement with the DNA homology results. These rhizobia therefore appear to form a unique taxonomic group within the genus Rhizobium. The fast-growing soybean nodulating rhizobia formed a distinct DNA homology group with at least two subgroups. The mean relative homology of 11 of these strains with the reference strains USDA 208 and USDA 191 which nodulate Glycine max, was significantly higher than the mean relative homology of other groups of rhizobia. Low DNA homologies were found between the fast-growing soybean strains and Bradyrhizobium japonicum ATCC 10324. The fast-growing soybean nodulating rhizobia nodulated glycine max and formed ineffective nodules on Lotus pedunculatus. None of these strains were lysed by the bacteriophages used in the study, but as yet, no bacteriophage specific for this group of rhizobia has been isolated. The fast­ growing soybean nodulating rhizobia were concluded to be taxonomically distinct from other species of Rhizobium. The thermal stability of reassociated DNA duplexes was examined for both the Galega and fast-growing soybean rhizobia and further indicated the uniqueness of both groups. The use of colony hybridization as a means of identifying different strains of Rhizoiium was investigated and was found to be useful in distinguishing between genetically distinct rhizobia and to identify rhizobia within root nodules

    Introduction

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    The ACademic DireCtory - AC/DC

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    AC/DC (See URL http://acdc.hensa.ac.uk) is an experimental, collaborative research project that indexes and allows searches over all public academic WWW servers in the UK. This report describes why AC/DC was created, how it is built from existing software, the collaborative process used to collect and index the data and future activities

    Arterial dysgenesis and limb defects : Clinical and experimental examples

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    Acknowledgements This article is dedicated to Dr David S. Packard Jr. With thanks to Dr John DeSesso, Dr Lewis B. Holmes, Dr Mark Levinsohn, Dr David S. Packard Jr, Prof Lewis Wolpert for discussions on vascular disruption, particularly arterial dysgenesis and limb defects. We apologise to the many authors whose work we were unable to cite due to space limitations. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Peer reviewedPostprin

    The DVD vs. DIVX Standard War: Empirical Evidence of Vaporware

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    In this paper, we empirically measure the effect of the DIVX preannouncement in the DVD market. We do this by measuring the effect of potential (incompatible) competition on a network undergoing growth. We find that there are network effects in the DVD market and that the preannouncement of DIVX slowed down the adoption of DVD technology. This suggests that strategic preannouncements can indeed affect the outcome of a standards competition.

    The string partition function in Hull's doubled formalism

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    T-duality is one of the essential elements of string theory. Recently, Hull has developed a formalism where the dimension of the target space is doubled so as to make T-duality manifest. This is then supplemented with a constraint equation that allows the connection to the usual string sigma model. This paper analyses the partition function of the doubled formalism by interpreting the constraint equation as that of a chiral scalar and then using holomorphic factorisation techniques to determine the partition function. We find there is quantum equivalence to the ordinary string once the topological interaction term is included.Comment: 16 pages, latex, v2 typos corrected, v3 some comments adde

    The other GMP: good manufacturing practice and its importance in the validation of constructed pharmaceutical facilities

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    The work reported is part of an ongoing PhD study prompted by the particular difficulties encountered when two very different quality cultures interact (in this case Pharmaceutical industry clients and Construction industry providers). Pharmaceutical facilities have particular needs for their production requirements. Stringent regulations are set by regulatory bodies such as the Medicines and Healthcare products Regulatory Agency (MHRA) (in the UK) and the Food and Drugs Administration (FDA) in the US. This creates special problems of quality when it comes to the commissioning, validation and hand-over of the building, as it appears to be at odds with the rather less demanding quality systems that are normally accepted in the construction sector. The aim of the research is to model an acceptable process for incorporating these stringent validation requirements into the design, procurement and construction processes. There is little or no specific academic literature on the subject, though the trades and professional press (particularly in the USA) provide some normative comment on the problem area. The main academic grounding of the research is in Systems Theory and empirical data is being collecting using a multiple case study approach. Research data was collected from a number of pharmaceutical facility construction case studies and was used to test and inform a best practice model of facility validation. The qualitative methods of participant and direct observation were used as the main information gathering tools. The paper reports on the regulatory expectations that influence the construction of projects of this type and the impact on the best practice model of validation
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