6,150 research outputs found

    Genus Bounds for Harmonic Group Actions on Finite Graphs

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    This paper develops graph analogues of the genus bounds for the maximal size of an automorphism group of a compact Riemann surface of genus g≥2g\ge 2. Inspired by the work of M. Baker and S. Norine on harmonic morphisms between finite graphs, we motivate and define the notion of a harmonic group action. Denoting by M(g) the maximal size of such a harmonic group action on a graph of genus g≥2g\ge 2, we prove that 4(g−1)≤M(g)≤6(g−1)4(g-1)\le M(g)\le 6(g-1), and these bounds are sharp in the sense that both are attained for infinitely many values of g. Moreover, we show that the values 4(g−1)4(g-1) and 6(g−1)6(g-1) are the only values taken by the function M(g)M(g).Comment: 14 pages with 6 figures; section 8 rewritten to correct an error in lemma 8.2; published versio

    Women's participation in crusades from the eleventh to thirteenth centuries : a thesis presented in fulfilment of the requirements for the degree of Master of Arts at Massey University

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    This thesis studies the involvement of women in the four great armed pilgrimages, the crusades of 1096-1204. A crusade was a pilgrimage, an act of penance for the sins of its participants, as well as being a holy war. Women were entitled to join pilgrimages because it was an act they had enjoyed for centuries. When, therefore, the armed pilgrimage was preached by Urban II in 1095, women too were permitted to journey although it was not anticipated at first by the papacy that they would. The presence of women in ritually pure camps and on the battlefields was objected to. The biblical beliefs of chroniclers and moralists of the period held that the presence of women on these campaigns compromised their purpose. This thesis will examine in primary sources the beliefs of the moralists and writers of the crusades, and the responses to the presence of women on campaigns

    An interesting intraoperative decision.

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    Simultaneous administration of adjuvant donor bone marrow in pancreas transplant recipients

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    Objective: The effect of donor bone marrow was evaluated for its potentially favorable effect in the authors' simultaneous pancreas/kidney transplant program. Methods: From July 1994 to January 1999, 177 pancreas transplants were performed, 151 of which were simultaneous pancreas/kidney transplants. All patients received tacrolimus, mycophenolate mofetil, and steroids for immunosuppression (azathioprine was used in the first year of the program). Fifty-three simultaneous pancreas/kidney transplant recipients received perioperative unmodified donor bone marrow, 3 to 6 x 108 cells/kg. Results: Overall actuarial survival rates at 1 and 3 years were 98% and 95% (patient), 95% and 87% (kidney), and 86% and 80% (pancreas), respectively. In the adjuvant bone marrow group, 1- and 3-year survival rates were 96% and 91% (patient), 95% and 87% (kidney), and 83% and 83% (pancreas), respectively. For 98 recipients who did not receive bone marrow, survival rates at 1 and 3 years were 100% and 98% (patient), 96% and 86% (kidney), and 87% and 79% (pancreas), respectively. No pancreas allografts were lost after 3 months in bone marrow recipients, and seven in the non-bone marrow recipients were lost to rejection at 0.7, 6.7, 8.8, 14.6, 24.1, 24.3, and 25.5 months. Twenty-two percent of bone marrow patients were steroid-free at 1 year, 45% at 2 years, and 67% at 3 years. Nineteen percent of the non-bone marrow recipients were steroid-free at 1 year, 38% at 2 years, and 45% (p = 0.02) at 3 years. The mean acute cellular rejection rate was 0.94 ± 1.1 in the bone marrow group and 1.57 ± 1.3 (p = 0.003) in the non-bone marrow group (includes borderline rejection and multiple rejections). The level of donor cell chimerism in the peripheral blood of bone marrow patients was at least two logs higher than in controls. Conclusion: In this series, which represents the largest experience with adjuvant bone marrow infusion in pancreas recipients, there was a higher steroid withdrawal rate (p = 0.02), fewer rejection episodes, and no pancreas graft loss after 3 months in bone marrow recipients compared with contemporaneous controls. All pancreas allografts lost to chronic rejection (n = 6) were in the non-bone marrow group. Donor bone marrow administered around the time of surgery may have a protective effect in pancreas transplantation

    Representing simmodel in the web ontology language

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    Many building energy performance (BEP) simulation tools, such as EnergyPlus and DOE-2, use custom schema definitions (IDD and BDL respectively) as opposed to standardised schema definitions (defined in XSD, EXPRESS, and so forth). A Simulation Domain Model (SimModel) was therefore proposed earlier, representative for a new interoperable XML-based data model for the building simulation domain. Its ontology aims at moving away from tool-specific, non-standard nomenclature by implementing an industry-validated terminology aligned with the Industry Foundation Classes (IFC). In this paper, we document our ongoing efforts to make building simulation data more interoperable with other building data. In order to be able to better integrate SimModel information with other building information, we have aimed at representing this information in the Resource Description Framework (RDF). A conversion service has been built that is able to parse the SimModel ontology in the form of XSD schemas and output a SimModel ontology in OWL. In this article, we document this effort and give an indication of what the resulting SimModel ontology in OWL can be used for

    Changes of water quality and sediment phosphorus of a small productive lake following decreased phosphorus loading

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    Esthwaite Water is the most productive or eutrophic lake in the English Lake District. Since 1945 its water quality has been determined from weekly or biweekly measurements of temperature, oxygen, plant nutrients and phytoplankton abundance. The lake receives phosphorus from its largely lowland-pasture catchment, sewage effluent from the villages of Hawkshead and Near Sawrey, and from a cage-culture fish farm. From 1986 phosphorus has been removed from the sewage effluent of Hawkshead which was considered to contribute between 47% and 67% of the total phosphorus loading to the lake. At the commencement of phosphorus removal regular measurements of phosphorus in the superficial 0-4 cm layer of lake sediment were made from cores collected at random sites. Since 1986 the mean annual concentration of alkali-extractable sediment phosphorus has decreased by 23%. This change is not significant at the 5% level but nearly so. There has been no marked change in water quality over this period. Summer dominance of blue-green algae which arose in the early 1980s after decline of the previous summer forms, Ceratium spp., has been maintained. Improvement in water quality is unlikely to be achieved at the present phosphorus loading
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