Phase transition from hadronic matter to quark matter

We study the phase transition from nuclear matter to quark matter within the SU(3) quark mean field model and NJL model. The SU(3) quark mean field model is used to give the equation of state for nuclear matter, while the equation of state for color superconducting quark matter is calculated within the NJL model. It is found that at low temperature, the phase transition from nuclear to color superconducting quark matter will take place when the density is of order 2.5$\rho_0$ - 5$\rho_0$. At zero density, the quark phase will appear when the temperature is larger than about 148 MeV. The phase transition from nuclear matter to quark matter is always first order, whereas the transition between color superconducting quark matter and normal quark matter is second order.Comment: 18 pages, 11 figure

The Conservative party in north-east Wales, 1906-1924

Between 1906 and 1924 the Conservative party only won three parliamentary elections in North-east Wales - the Denbigh Boroughs division twice in 1910 and the county seat in Flintshire in 1924. Conversely the Liberal party won all the other elections throughout the period, with the exception of Wrexham which fell to Labour in 1922 and 1923. This, however, says more about the vagaries of the British 'first past the post' electoral system than it does about the true strength of the political parties in the region. Indeed, between 1906 and 1924 the Conservative party never averaged below 39 per cent of the electorate in the constituencies it contested. Given this impressive but unrecognised electoral position, what this study set out to do was to analyse the strength of Conservatism in a region where failure was the norm. The period was chosen because it saw the last Liberal administration in this country, and marked the start of the Conservative dominance of government for much of the twentieth century. It also saw one of the biggest cultural and social upheavals in British history with the advent of the First World War, and witnessed the enfranchisement of women for the first time. The general election of 1906 returned no Conservatives for Wales. In North Wales a conference was called to examine the situation and evaluate future prospects. This led to a review of party organisation in the region, the intention being not only to attract more working class people and women, but also to lessen the autocratic domination by the landed classes. In 1910 the Conservatives won the Denbigh Boroughs constituency with a large swing against the Liberals, and came very close to winning the Flint Boroughs by-election of 1913. The period of War, 1914-1918, saw all political parties moth-balled until the end of hostilities, but during the period of Coalition Government from 1918 to 1922 in which Liberal representation went almost unchallenged in North-east Wales, the Conservatives reorganised their Constituency Associations. By 1924 the landed domination of the party had diminished significantly, and in Flintshire the Conservatives won their first seat in an industrial working class area. Underpinning this success was a long-standing popular support, which after 1906 was better organised and mobilised for the Conservative cause through a variety of loosely attached organisations, societies and clubs. The Primrose League, an organisation that had been founded in 1883 to rally Conservative support, had a very high membership in the region compared to the rest of Wales. For example, the Denbigh Primrose League had over 800 members in 1912. A network of Conservative clubs existed in the region and as early as 1905 a thriving Workingmen's Association had been founded in Wrexham. The Conservative party was also well represented in local government; in Flintshire between 1907 and 1913 it had more county councillors than the Liberal party. In addition, the upheaval of War and the attraction of socialism to the newly enfranchised masses meant that the Conservative party had to widen its appeal to those people who had acquired the vote in 1918. By recruiting women and working class members the Conservative party was able to lay the foundations for a number of parliamentary successes in North-east Wales that lasted until the 1990s. It is therefore the contention of this thesis that the Conservative party not only survived a very difficult period, but that it emerged a strengthened and invigorated force

Japanese Beef Policy and GATT Negotiations: An Analysis of Reducing Assistance to Beef Producers

International Development, Livestock Production/Industries,

Scale-free networks in complex systems

In the past few years, several studies have explored the topology of interactions in different complex systems. Areas of investigation span from biology to engineering, physics and the social sciences. Although having different microscopic dynamics, the results demonstrate that most systems under consideration tend to self-organize into structures that share common features. In particular, the networks of interaction are characterized by a power law distribution, $P(k)\sim k^{-\alpha}$, in the number of connections per node, $k$, over several orders of magnitude. Networks that fulfill this propriety of scale-invariance are referred to as ``scale-free''. In the present work we explore the implication of scale-free topologies in the antiferromagnetic (AF) Ising model and in a stochastic model of opinion formation. In the first case we show that the implicit disorder and frustration lead to a spin-glass phase transition not observed for the AF Ising model on standard lattices. We further illustrate that the opinion formation model produces a coherent, turbulent-like dynamics for a certain range of parameters. The influence, of random or targeted exclusion of nodes is studied.Comment: 9 pages, 4 figures. Proceeding to "SPIE International Symposium Microelectronics, MEMS, and Nanotechnology", 11-15 December 2005, Brisbane, Australi

In-medium electron-nucleon scattering

In-medium nucleon electromagnetic form factors are calculated in the quark meson coupling model. The form factors are typically found to be suppressed as the density increases. For example, at normal nuclear density and $Q^2 \sim 0.3 { GeV}^2$, the nucleon electric form factors are reduced by approximately 8% while the magnetic form factors are reduced by only 1 - 2%. These variations are consistent with current experimental limits but should be tested by more precise experiments in the near future.Comment: 14 pages, latex, 3 figure

Liquid-gas phase transition in nuclear matter including strangeness

We apply the chiral SU(3) quark mean field model to study the properties of strange hadronic matter at finite temperature. The liquid-gas phase transition is studied as a function of the strangeness fraction. The pressure of the system cannot remain constant during the phase transition, since there are two independent conserved charges (baryon and strangeness number). In a range of temperatures around 15 MeV (precise values depending on the model used) the equation of state exhibits multiple bifurcates. The difference in the strangeness fraction $f_s$ between the liquid and gas phases is small when they coexist. The critical temperature of strange matter turns out to be a non-trivial function of the strangeness fraction.Comment: 15 pages, 7 figure

Loss of dependence on IGF-1 for proliferation of human thyroid adenoma cells.

The proliferative responses to IGF-1 (Somatomedin C) and TSH, as assessed by 3H-thymidine (3H-TdR) incorporation and autoradiographic labelling index (LI), of suspension and monolayer cultures of human thyroid follicular epithelium derived from both normal and adenoma tissue have been compared. In cultures of normal follicles, whilst neither TSH nor IGF-1 alone produced any effect, a combination of TSH (0.1 mU ml-1) together with IGF-1 (10 ng ml-1) induced a highly significant proliferative response as shown by a peak of 3HTdR incorporation and LI, 4-5 days after growth factor addition. The TSH concentration-effect curve was bell-shaped, a higher concentration of TSH (10 mU ml-1) resulting in a reduced response. In cultures derived from adenoma tissue, however, TSH alone at 0.1 mU ml-1 was sufficient to permit a highly significant proliferative response (equivalent to, or greater than the normal) in 4 out of 5 adenomas examined; again a higher concentration of TSH (10 mU ml-1) resulted in a diminished response. Addition of IGF-1 (10 ng ml-1) produced no significant change in the response to TSH (0.1 mU ml-1) in 3 of these 4 adenomas, and significantly inhibited the response in the fourth adenoma. It is concluded that escape from the requirement for an exogenous source of IGF-1 may be a key step in the development of human thyroid epithelial (follicular cell) neoplasia