17,709 research outputs found
Lautman and the Reality of Mathematics
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
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
New Labour, new environment? An analysis of the labour government's policy on climate change and biodiversity loss
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The ACademic DireCtory - AC/DC
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
Dyonic Instantons in Five Dimensional Gauge Theories
We show that there exist finite energy, non-singular instanton solutions for
five-dimensional theories with broken gauge symmetry. The soliton is supported
against collapse by a non-zero electric charge. The low-energy dynamics of
these solutions is described by motion on the ADHM moduli space with potential.Comment: 9 pages. Latex. Minor typos, including correction to final equatio
Arterial dysgenesis and limb defects : Clinical and experimental examples
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
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
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
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