Correlations of πN\boldsymbol{\pi N} Partial Waves for Multi-Reaction Analyses

In the search for missing baryonic resonances, many analyses include data from a variety of pion- and photon-induced reactions. For elastic $\pi N$ scattering, however, usually the partial waves of the SAID or other groups are fitted, instead of data. We provide the partial-wave covariance matrices needed to perform correlated $\chi^2$ fits, in which the obtained $\chi^2$ equals the actual $\chi^2$ up non-linear and normalization corrections. For any analysis relying on partial waves extracted from elastic pion scattering, this is a prerequisite to assess the significance of resonance signals and to assign any uncertainty on results. The influence of systematic errors is also considered.Comment: 7 pages, 3 figures; Acknowledgements update

Effect of exotic S=+1 resonances on KL0pK^0_L p scattering data

We consider the effect of an exotic S=+1 $\Theta^+$ resonance on the scattering of neutral kaons off protons. Explicit results are presented for the $K^0_L p$ total cross sections.Comment: 2 pages, 3 figure

Effect of Sigma-beam Asymmetry Data on Fits to Single Pion Photoproduction off Neutron

We investigate the influence of new GRAAL Sigma-beam asymmetry measurements on the neutron in multipole fits to the single-pion photoproduction database. Results are compared to those found with the addition of a double-polarization quantity associated with the sum rule.Comment: 4 pages, 4 figures, 1 table; v2/v3: minor corrections; Presented at the 8th Workshop on the Physics of Excited Nucleons (NSTAR2011), Newport News, USA, May 201

Toward a unified description of hadro- and photoproduction amplitudes

The near-term objectives of the research program at the Data Analysis Center are established within the context of the existing partial wave analyses available through the online suite of analysis and database codes accessible through SAID, the Scattering Analysis Interactive Database. This presentation reviews the efforts to determine a model independent method to obtain sets of partial wave amplitudes for strong and electromagnetic reactions, the interpretation of the amplitudes in terms of the excited states of the nucleon, the role of new precision unpolarized and polarized data, and new developments aimed at determining the photoproduction mulitpoles in a unitary, coupled-channel approach. The Chew-Mandelstam technique is discussed and applied to the problem of the S-wave pion- and eta-photoproduction amplitudes. The resulting eta production amplitudes exhibit the expected resonant behavior near the eta production threshold. Application of this method to a unified description of the hadro- and photoproduction amplitudes is discussed.Comment: 4 pages, 1 figure, invited talk for the 12th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon (MENU 2010), Williamsburg, Virginia, 31 May - 4 Jun 201

Valuing energy futures; a comparative analysis of value pools across UK energy system scenarios

Electricity markets in liberalised nations are composed primarily of private firms that make strategic decisions about how to secure competitive advantage. Energy transitions, driven by decarbonisation targets and technological innovation, will create new markets and destroy old ones in a re-configuration of the power sector. This research suggests that by 2050 up to 21bnGBP per year of new financial value is available in the UK electricity system, and that depending on scenario, these new values represent up to 31% of the entire electricity sector. To service these markets business model innovation and new firm strategies are needed in electric power provision. Energy scenarios can inform strategic decisions over business model adaptation, but to date scenario modelling has not directly addressed firm strategy and behaviour. This is due in part to neo-classical assumptions of firm rationality and perfect foresight. This research adopts a resource based view of the firm rooted in evolutionary economics to argue that quantifying the relative size of the markets created and destroyed by energy transitions can provide useful insight into firm behaviour and innovation policy

Pharmacokinetic considerations in testing hypoxic cell radiosensitizers in mouse tumours.

Bilateral kidney ligation of mice immediately before injection of misonidazole (MIS) prolongs the plasma half-life of this radiosensitizer from about 2 h (in normal mice) to 10-11 h, similar to that in man. Kidney ligation does not, however, change the relative proportions of MIS and its O-demethylated metabolite, Ro-05-9963, for the first 12 h after MIS injection. Kidney ligation was used with the two radiosensitizers, MIS and Ro-05-9963, to investigate the influence of plasma half-life both on peak plasma levels and on the tumour/plasma ratio of sensitizer concentration in the EMT6 mouse tumour. Although the acute LD50 of Ro-05-9963 in normal mice was twice that of MIS, this apparent advantage was offset by peak tumour levels 50% or less of those achieved by equimolar injected doses of MIS. However, by comparing the plasma and tumour levels in mice in which the drug half-lives were prolonged by bilateral kidney ligation, it was concluded that the lower plasma and tumour levels of Ro-05-9963 were a result of its shorter plasma half-life, rather than of an intrinsic barrier to tumour penetration. Because of this rapid clearance, the radiosensitization produced by Ro-05-9963 was less than that produced by equimolar injected doses of MIS. As this difference did not occur in kidney-ligated mice, and hence would not be expected to occur in man, the comparison of MIS and Ro-05-9963 in mice produces an artificially low radiosensitization for Ro-05-9963 and possibly also for other compounds with short plasma half-lives. Although the short plasma half-life of Ro-05-9963 appeared to be responsible for its low peak plasma concentration, it did not produce a low tumour/plasma ratio. Within the limits of plasma nitroimidazole half-lives investigated (0.5-10 h) the tumour/plasma ratio was insensitive to plasma half-life, being 50-70% for both MIS and Ro-05-9963 in both normal and kidney-ligated mice. It is concluded that the common assumption that tumour/plasma ratios of MIS in the mouse are less than those in man is unjustified

Remodelling of human atrial K+ currents but not ion channel expression by chronic β-blockade

Chronic β-adrenoceptor antagonist (β-blocker) treatment in patients is associated with a potentially anti-arrhythmic prolongation of the atrial action potential duration (APD), which may involve remodelling of repolarising K+ currents. The aim of this study was to investigate the effects of chronic β-blockade on transient outward, sustained and inward rectifier K+ currents (ITO, IKSUS and IK1) in human atrial myocytes and on the expression of underlying ion channel subunits. Ion currents were recorded from human right atrial isolated myocytes using the whole-cell-patch clamp technique. Tissue mRNA and protein levels were measured using real time RT-PCR and Western blotting. Chronic β-blockade was associated with a 41% reduction in ITO density: 9.3 ± 0.8 (30 myocytes, 15 patients) vs 15.7 ± 1.1 pA/pF (32, 14), p < 0.05; without affecting its voltage-, time- or rate dependence. IK1 was reduced by 34% at −120 mV (p < 0.05). Neither IKSUS, nor its increase by acute β-stimulation with isoprenaline, was affected by chronic β-blockade. Mathematical modelling suggested that the combination of ITO- and IK1-decrease could result in a 28% increase in APD90. Chronic β-blockade did not alter mRNA or protein expression of the ITO pore-forming subunit, Kv4.3, or mRNA expression of the accessory subunits KChIP2, KChAP, Kvβ1, Kvβ2 or frequenin. There was no reduction in mRNA expression of Kir2.1 or TWIK to account for the reduction in IK1. A reduction in atrial ITO and IK1 associated with chronic β-blocker treatment in patients may contribute to the associated action potential prolongation, and this cannot be explained by a reduction in expression of associated ion channel subunits