33,840 research outputs found
"Freedom of Movement within 'Fortress Europe'"
Introduction. Much attention has been focused on those seeking to enter âfortress Europeâ  whether the concept is understood to refer only to the EU Schengen countries or to include non-EU Schengen countries, the United Kingdom and Ireland, or the countries which joined the Union in May 2004. Yet internal mobility within âfortress Europeâ is at least as worthy of consideration. The rise of freedom of movement rights in Europe  now codified with the legal category of European Union citizenship  represents a startling reversal of the historical tradition of state sovereignty. States have historically been defined in terms of insiders (citizens) and outsiders (foreigners). The new supranational rights supersede this traditional distinction by reducing or even removing the ability of European states to discriminate between their own citizens and those of other EU member states. Borders within the European Union still matter, but the remaining barriers to freedom of movement within âfortress Europeâ are practical rather than legal, and even they are rapidly disappearing. Exceptions to the European free movement regime still exist  such as the case of individuals deemed to pose a significant threat to public health or public security. But the rights of free movement have now been extended to virtually all European citizens, even though there will be a phase-in period for workers from most of the new accession states. By contrast, third-country nationals  citizens neither of the host state (first country) nor of another EU member state (second country) but of a non-EU state  continue to be denied freedom of movement rights within the Union, despite the efforts of the Commission and some national governments to extend them the same rights as those enjoyed by EU citizens. Exceptions to Schengen also continue to exist, as with special events such as the European soccer cup, for which Portugal in 2004 (just as Belgium and the Netherlands in 2000) was granted a temporary exemption on the requirement to abstain from checking the identification of individuals crossing Portuguese borders. On the whole, however, the picture that emerges for freedom of movement within Europe is one of a continent in which Europeans can move about freely, and in which state borders (though clearly not the borders between âfortress Europeâ and the rest of the world!) have lost most of the significance they once possessed. This paper lays out the development of the Schengen system and places it within the context of European Union citizenship
Strategies to control tree vigour and optimise fruit production in 'Conference' pears
The ban on the use of chlormequat (CCC) in pear orchards in 2001 forced Dutch pear growers to look for alternative methods to control tree vigour and stimulate flower bud development and fruit production. Root pruning and trunk notching have become the major growth retarding methods. In addition to the mechanical methods for controlling tree vigour, Regalis (Prohexadione-Calcium) and ethephon were tested as alternative chemical growth regulators for 'Conference' pears. In 2004, a trial was started in which six different strategies to control tree vigour and optimize fruit production in 'Conference' trees are compared. In 4 strategies root pruning was the major treatment, while in 2 strategies trunk incisions were the initial treatment to reduce tree vigour and stimulate fruit production. In 2005, no further root pruning or trunk incisions were made and ethephon and Regalis were the only treatments applied in some of the strategies. Ethephon and Regalis were also applied in 2006 in addition to root pruning in March and June or in June only. All of the strategies evaluated significantly reduced shoot growth and improved fruit production. Regular yields of 52 to more than 70 tons/ha were achieved for 3 consecutive years. So far, ethephon and Regalis have shown no or only minor additional beneficial effects compared to root pruning or trunk incision followed by root pruning in the years thereafter. Flowering, fruit yield and fruit quality of 'Conference' pears produced using the different strategies are presented and discussed
Constructing non-perturbative gauges using correlation functions
Gauge fixing in the non-perturbative domain of non-Abelian gauge theories is
obstructed by the Gribov-Singer ambiguity. To compare results from different
methods it is necessary to resolve this ambiguity explicitly. Such a resolution
is proposed using conditions on correlation functions for a family of
non-perturbative Landau gauges. As a consequence, the various results available
for correlation functions could possibly correspond to different
non-perturbative Landau gauges, discriminated by an additional non-perturbative
gauge parameter. The proposal, the necessary assumptions, and evidence from
lattice gauge theory calculations, are presented in detail.Comment: in v2: Various modifications, discussion of results and scenario
extended, references added in v3: Discussed definitions of what a Gribov
ambiguity, a resolution of the ambiguity, and a Gribov problem is. Various
minor improvement
Scalar-matter-gluon interaction
A full non-perturbative treatment of gauge theories requires to include
matter fields on equal footing with the gauge fields. Scalar matter can act as
a role model for generic matter, as many questions, e.g. confinement, can be
posed without referring to a particular Lorentz structure. Due to their rather
simple structure they are also useful to develop methods.
One possible way to describe gauge theories beyond perturbation theory is
based on correlation functions. After a short discussion of the setup, lattice
gauge theory is used to analyze the interaction of gluons with quenched
fundamental and adjoint scalars. Both the two-point and three-point correlation
functions for massive and massless adjoint and fundamental scalars will be
determined, in minimal Landau gauge. The findings are in agreement with the
possibility that scalars are only slightly affected by the interaction with
gluons. The results are compared briefly with dynamical, massive scalars,
showing no significant changes in the confinement region compared to the
quenched case.Comment: 10 pages, 3 figures, invited talk presented at the workshop "The many
faces of QCD", Ghent, Belgium, 1st of November-5th of November 2010;
submitted to the proceeding
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