Fractals and Scars on a Compact Octagon

A finite universe naturally supports chaotic classical motion. An ordered fractal emerges from the chaotic dynamics which we characterize in full for a compact 2-dimensional octagon. In the classical to quantum transition, the underlying fractal can persist in the form of scars, ridges of enhanced amplitude in the semiclassical wave function. Although the scarring is weak on the octagon, we suggest possible subtle implications of fractals and scars in a finite universe.Comment: 6 pages, 3 figs, LaTeX fil

Breeding for improved nitrogen use efficiency in oilseed rape

Oilseed rape has a high requirement for nitrogen (N) fertiliser relative to its seed yield. This paper uses published and unpublished work to explore the extent to which the N use efficiency (seed yield ÷ N supply) of oilseed rape could be improved without reducing seed yield. It was estimated that if the concentration of N in the stem and pod wall at crop maturity could be reduced from 1.0 to 0.6%, the root length density increased to 1 cm/cm3 to 100 cm soil depth and the post flowering N uptake increased by 20 kg N/ha then the fertiliser requirement could be reduced from 191 to 142 kg N/ha and the N use efficiency could be increased from 15.2 to 22.4 kg of seed dry matter per kg N. Genetic variation was found for all of the traits that were estimated to be important for N use efficiency. This indicates that there is significant scope for plant breeders to reduce N use efficiency in oilseed rape

Internal Frame Dragging and a Global Analog of the Aharonov-Bohm Effect

It is shown that the breakdown of a {\it global} symmetry group to a discrete subgroup can lead to analogues of the Aharonov-Bohm effect. At sufficiently low momentum, the cross-section for scattering of a particle with nontrivial $\Z_2$ charge off a global vortex is almost equal to (but definitely different from) maximal Aharonov-Bohm scattering; the effect goes away at large momentum. The scattering of a spin-1/2 particle off a magnetic vortex provides an amusing experimentally realizable example.Comment: (14 pp

Detection of Campylobacter concisus and other Campylobacter species in colonic biopsies from adults with ulcerative colitis

Peer reviewedPublisher PD

The effect of Holstein-Friesian genotype and feeding system on selected performance parameters of dairy cows on grass-based systems of milk production in Ireland

End of project reportThe overall objective of this project was to assess, the effect of strain of Holstein-Friesian dairy cow, pasture-based feed system (FS) and their interaction on animal performance in terms of milk productivity and lactation profile, body weight (BW), body condition score (BCS), feed intake and energy balance (EB), reproductive performance and overall economic profitability

The relationship between oxidised LDL, endothelial progenitor cells and coronary endothelial function in patients with CHD

Objective The balance between coronary endothelial dysfunction and repair is influenced by many protective and deleterious factors circulating in the blood. We studied the relationship between oxidised low-density lipoprotein (oxLDL), circulating endothelial progenitor cells (EPCs) and coronary endothelial function in patients with stable coronary heart disease (CHD). Methods 33 patients with stable CHD were studied. Plasma oxLDL was measured using ELISA, coronary endothelial function was assessed using intracoronary acetylcholine infusion and EPCs were quantified using flow cytometry for CD34+/KDR+ cells. Results Plasma oxLDL correlated positively with the number of EPCs in the blood (r=0.46, p=0.02). There was a positive correlation between the number of circulating EPCs and coronary endothelial function (r=0.42, p=0.04). There was no significant correlation between oxLDL and coronary endothelial function. Conclusions Plasma levels of oxLDL are associated with increased circulating EPCs in the blood of patients with CHD, which may reflect a host-repair response to endothelial injury. Patients with stable CHD had a high prevalence of coronary endothelial dysfunction, which was associated with lower numbers of circulating EPCs, suggesting a mechanistic link between endothelial dysfunction and the pathogenesis of atherosclerosis

Role of Inflammation in 20-HETE Regulation of Ischemia-Induced Angiogenesis

Objective: 20-Hydroxyeicosatetraenoic acid (20-HETE), an important bioactive lipid metabolite, has recently been identified to be a novel contributor of angiogenesis secondary to ischemia. Moreover, an inflammatory response is required for the initiation of ischemic angiogenesis, in response to ischemic tissue injury. The goal of this study is to investigate the role of inflammation in 20-HETE regulation of ischemia-induced angiogenesis. Methods: We first established a mouse hind limb ischemia model for immunocompetent Balb/C mice and immunodeficient NOD-SCID mice by femoral artery ligation. Groups of Balb/C and NOD-SCID mice were administered a 20-HETE synthesis inhibitor, DDMS, or saline as a solvent control. Laser Doppler perfusion imaging (LDPI) was used to visualize and quantify blood perfusion on days 0, 1, 3, 7, 14, and 21 post ligation, confirmed by microvessel density analysis. LC/MS/MS analysis was performed on day 3 post ligation on ischemic and non-ischemic control gracilis muscles to measure 20-HETE levels. Additionally, an antibody to lymphocyte antigen 6 complex (Ly6G/C) was administered to neutralize the infiltration of neutrophils, macrophages, and monocytes. 20-HETE levels were again measured on day 3 post ligation in these mice. Results: Quantification of the compensatory blood perfusion recovery post ischemia by LDPI showed that immunocompetent Balb/C control mice demonstrated a normal course of the compensatory angiogenic response while NOD-SCID immunodeficient mice showed a significantly decreased response. Additionally, DDMS was shown to inhibit the compensatory response in Balb/C mice, while no inhibitory effect was observed in immunodeficient NOD-SCID mice. This observation is confirmed by a marked decrease in microvessel density in SCID mice (1.5±0.2) post ischemia compared to immunocompetent Balb/C mice (2.65±0.32). As expected, ischemia markedly increased 20-HETE levels in the ischemic gracilis muscle of Balb/C mice by 6-fold (6±2 in non-ischemic vs 27±5 pg/mg in ischemic), while levels in NOD-SCID mice showed no change between the ischemic and non-ischemic control. Lastly, Balb/C mice that were treated with Ly6G/C neutralizing antibody exhibited significantly decreased 20-HETE levels in their ischemic gracilis muscle compared to the non-ischemic control. Conclusion: Inflammation may be an essential contributor in 20-HETE regulation of the ischemia-induced angiogenic response

Three dimensional graphics station for computer integrated manufacturing research

Issued as Final report, Project no. E-25-69