A note on the effect of post-mortem maturation on colour of bovine Longissimus dorsi muscle

peer-reviewedFinancial support to P.G. Dunne was provided under the Walsh Fellowship programme of Teagasc.Fifteen heifers were housed and fed a concentrate diet while 54 counterparts grazed at pasture for 90 days at which stage six heifers from each group were slaughtered. The remaining animals in the pasture group were then housed and offered either: concentrate only; concentrate plus grass silage with silage accounting for either 20% or 50% of the total dry matter offered; or zero-grazed grass plus concentrate with grass accounting for 83% of the dry matter offered. Heifers (3/diet) were slaughtered 28, 56, 91 and 120 days thereafter. Colour characteristics of M. longissimus dorsi (LD) were measured at 48 h post mortem. The LD was then vacuum-packaged and stored at between 0 and 4 °C in darkness for 12 days, when colour characteristics were again measured. Maturation of LD resulted in meat that had higher redness values (‘a’ value; P<0.001) and a more intense red colour (higher ‘C’ value; P<0.001) at 14 days post mortem than at 2 days, regardless of diet/duration of feeding. Maturation also resulted in a brighter colour (higher ‘L’ value; P<0.001) but this difference was greatest when cattle were slaughtered the day-56 time point

Hopf instantons, Chern-Simons vortices, and Heisenberg ferromagnets

The dimensional reduction of the three-dimensional fermion-Chern-Simons model (related to Hopf maps) of Adam et el. is shown to be equivalent to (i) either the static, fixed--chirality sector of our non-relativistic spinor-Chern-Simons model in 2+1 dimensions, (ii) or a particular Heisenberg ferromagnet in the plane.Comment: 4 pages, Plain Tex, no figure

Exotic galilean symmetry and the Hall effect

The ``Laughlin'' picture of the Fractional Quantum Hall effect can be derived using the ``exotic'' model based on the two-fold centrally-extended planar Galilei group. When coupled to a planar magnetic field of critical strength determined by the extension parameters, the system becomes singular, and ``Faddeev-Jackiw'' reduction yields the ``Chern-Simons'' mechanics of Dunne, Jackiw, and Trugenberger. The reduced system moves according to the Hall law.Comment: Talk given by P. A. Horvathy at the Joint APCTP- Nankai Symposium. Tianjin (China), Oct.2001. To appear in the Proceedings, to be published by Int. Journ. Mod. Phys. B. 7 pages, LaTex, IJMPB format. no figure

Exotic plasma as classical Hall Liquid

A non-relativistic plasma model endowed with an ``exotic'' structure associated with the two-parameter central extension of the planar Galilei group is constructed. Introducing a Chern-Simons statistical gauge field provides us with a self-consistent system; when the magnetic field takes a critical value determined by the extension parameters, the fluid becomes incompressible and moves collectively, according to the Hall law.Comment: 11 pages, LaTex, no figures. Revised version: Some details better explained. To appear in Int. Journ. Mod. Phys.

A Note on Schwinger Mechanism and a Nonabelian Instability in a Nonabelian Plasma

We point out that there is a nonabelian instability for a nonabelian plasma which does not allow both for a net nonzero color charge and the existence of field configurations which are coherent over a volume $v$ whose size is determined by the chemical potential. The basic process which leads to this result is the Schwinger decay of chromoelectric fields, for the case where the field arises from commutators of constant potentials, rather than as the curl of spacetime dependent potentials. In terms of the fields, instability is obtained when Tr(DF)^2 > 0.Comment: 14 pages, 6 figure

The Demand for Military Expenditure in Developing Countries: Hostility versus Capability

This paper has considers the interpretation of the empirical results of the developing literature on the demand for military spending that specifies a general model with arms race and spillover effects and estimates it on cross-section and panel data. It questions whether it is meaningful to talk of an ‘arms race’ in panel data or cross-section data, and suggests that it may be more appropriate to talk about the relevant variables – aggregate military spending of the ‘Security Web’ (i.e. all neighbours and other security-influencing powers) and the aggregate military spending of ‘Potential Enemies’– as acting as proxies for threat perceptions, which will reflect both hostility and capability.Military Spending, Developing Countries, Demand.

The role of HER1-HER4 and EGFRvIII in hormone-refractory prostate cancer

&lt;b&gt;Purpose&lt;/b&gt;: The role of the type I receptor tyrosine kinase (HER) family in progression of prostate cancer is controversial. Breast cancer studies show that these receptors should be investigated as a family. The current study investigates expression of HER1-HER4 and EGFRvIII in matched hormone-sensitive and hormone-refractory prostate tumors. &lt;b&gt;Experimental Design&lt;/b&gt;: Immunohistochemical analysis was used to investigate protein expression of HER1-HER4, EGFRvIII, and phosphorylated Akt (pAkt) in matched hormone-sensitive and hormone-refractory prostate tumors. &lt;b&gt;Results&lt;/b&gt;: Surprisingly, high HER2 membrane expression in hormone-sensitive tumors was associated with an increased time to biochemical relapse (&lt;i&gt;P&lt;/i&gt; = 0.0003), and this translated into longer overall survival (&lt;i&gt;P&lt;/i&gt; = 0.0021). Consistent with other studies, HER4 membrane expression in hormone-sensitive tumors was associated with longer time to biochemical relapse (&lt;i&gt;P&lt;/i&gt; = 0.042), and EGFRvIII membrane expression was associated with shorter time to biochemical relapse (&lt;i&gt;P&lt;/i&gt; = 0.015). An increase in pAkt expression was associated with reduced survival (&lt;i&gt;P&lt;/i&gt; = 0.0098). Multivariate analysis showed that HER2 was an independent positive predictive marker of time to relapse in hormone-sensitive prostate tumors (&lt;i&gt;P&lt;/i&gt; = 0.014). In contrast, high HER2 expression in hormone-refractory tumors was associated with decreased time to death from biochemical relapse (&lt;i&gt;P&lt;/i&gt; = 0.039), and EGFRvIII nuclear expression was associated with decreased time to death from biochemical relapse and decreased overall survival (&lt;i&gt;P&lt;/i&gt; = 0.02 and &lt;i&gt;P&lt;/i&gt; = 0.005). &lt;b&gt;Conclusion&lt;/b&gt;: These results suggest that the HER family may have multiple roles in prostate cancer, and that expression of the proteins alone is insufficient to predict the biological response that they may elicit

Euler-Heisenberg lagrangians and asymptotic analysis in 1+1 QED, part 1: Two-loop

We continue an effort to obtain information on the QED perturbation series at high loop orders, and particularly on the issue of large cancellations inside gauge invariant classes of graphs, using the example of the l - loop N - photon amplitudes in the limit of large photons numbers and low photon energies. As was previously shown, high-order information on these amplitudes can be obtained from a nonperturbative formula, due to Affleck et al., for the imaginary part of the QED effective lagrangian in a constant field. The procedure uses Borel analysis and leads, under some plausible assumptions, to a number of nontrivial predictions already at the three-loop level. Their direct verification would require a calculation of this `Euler-Heisenberg lagrangian' at three-loops, which seems presently out of reach. Motivated by previous work by Dunne and Krasnansky on Euler-Heisenberg lagrangians in various dimensions, in the present work we initiate a new line of attack on this problem by deriving and proving the analogous predictions in the simpler setting of 1+1 dimensional QED. In the first part of this series, we obtain a generalization of the formula of Affleck et al. to this case, and show that, for both Scalar and Spinor QED, it correctly predicts the leading asymptotic behaviour of the weak field expansion coefficients of the two loop Euler-Heisenberg lagrangians.Comment: 28 pages, 1 figures, final published version (minor modifications, refs. added