Massive Dualities in Six Dimensions

We study compactifications of string theory and M-theory to six dimensions with background fluxes. The nonzero fluxes lead to additional mass parameters. We derive the S- and T-duality rules for the corresponding (massive) supergravity theories. Specifically, we investigate the massive T-duality between Type IIA superstring theory compactified on K3 with background fluxes and Type IIB superstring theory compactified on K3. Furthermore, we generalise to the massive case the 6D 'string-string' S-duality between M-theory on K3 x S^1 and the Heterotic String on T^4. Whereas in the case of massive T--duality the mass parameters are in the fundamental representation of the U-duality group O(4,20) we find that in the case of massive S-duality they are in the 3-index antisymmetric representation. In the latter case the mass parameters involved extend those of Kaloper and Myers. We apply our duality rules to massive brane solutions, like the domain wall solutions corresponding to the mass parameters and find new massive brane solutions. Finally, we discuss the higher-dimensional interpretation of the dualities and brane solutions.Comment: 28 page

Resource efficiency and economic implications of alternatives to surgical castration without anaesthesia

This paper presents an analysis of the economic implications of alternative methods to surgical castration without anaesthesia. Detailed research results on the economic implications of four different alternatives are reported. castration with local anaesthesia, castration with general anaesthesia, immunocastration and raising entire males. The first three alternatives have been assessed for their impact on pig production costs in the most important pig-producing Member States of the EU. The findings on castration with anaesthesia show that cost differences among farms increase if the anaesthesia cannot be administered by farmers and when the veterinarian has to be called to perform it. The cost of veterinarian service largely affects the total average costs, making this solution economically less feasible in small-scale pig farms. In all other farms, the impact on production costs of local anaesthesia is however limited and does not exceed 1 (sic)ct per kg. General anaesthesia administered by inhalation or injection of Ketamin in combination with a sedative (Azaperone, Midazolan) is more expensive. These costs depend heavily on farm size, as the inhalation equipment has to be depreciated on the largest number of pigs possible. The overall costs of immunocastration - including the cost of the work load for the farmer - has to be evaluated against the potential benefits derived from higher daily weight gain and feed efficiency in comparison with surgical castrates. The economic feasibility of this practice will finally depend on the price of the vaccine and on consumer acceptance of immunocastration, The improvement in feed efficiency may compensate almost entirely for the cost of vaccination. The main advantages linked to raising entire males are due to the higher efficiency of feed conversion, to the better growth rate and to the higher leanness of carcass. A higher risk of boar taint on the slaughter line has to be accounted for Raising entire males should not generate more than 2.5% of boar taint among slaughter pigs, in order to maintain the considerable economic benefits of better feed efficiency of entire males with respect to castrates

Cross compliance and competitiveness of the European beef and pig sector

Beef and pig production are important sectors affected by the cross-compliance policy. Full compliance with SMRs and GAECs generates costs and benefits which may have an impact on the competitiveness of these sectors on the world market. Compliance with the Nitrate Directive, animal identification and registration requirements and animal welfare standards can give rise to non-negligible cost of production increases at individual farm level and at sector level. Additional costs can be relevant either due to a low degree of compliance or by significant adjustments costs at farm level. Full compliance generates a level playing field between Member States of the EU, as some countries have to face higher additional costs than others, which are be attributed to differences in degree of compliance. This paper first presents evidence of additional costs at individual farm level due to full compliance. Then for beef and pork a methodology has been developed in order to calculate sector cost impacts following an upcsaling procedure for each of the analysed directives. Simulations with the GTAP model have enabled an assessment of the trade effect of compliance with standards and the impact on the external competitiveness of the EU beef and pork production. In some policy fields covered by cross-compliance important trade partners such as Canada, USA and New Zealand have implemented policies similar to the EU. In these three countries comparable standards to those in the EU were identified and the level and cost of compliance have been assessed. The pig sector will be affected most by a unilateral compliance with standards in the EU, in particular as the Nitrate Directive is concerned. Within the EU pig production costs will rise by 0.545 %. Imports may increase by 4% and exports may fall by 3%. However full application of the Clean Water Act in the US, which contains similar obligations to the Nitrate Directive, generates a significant sector cost increase (1,08%) which may counterbalance the loss of competitiveness of EU pork production towards the US. Compliance with the mandatory animal welfare standards has only minor cost implications and has negligible effects on external competitiveness of the EU both because of a high degree of compliance and relatively low adjustment costs at farm level. Finally, in many EU member states the degree of compliance of beef farms with the animal registration and identification directives is below 100%. Additional costs for full compliance within the EU have been estimated at 0.455%, which may cause an increase of beef imports of 2.21% and a decline of exports of ¿2.12%. This loss in competitiveness of the EU will further favour the position of Brazil on the world beef market. At the other hand significant benefits are obtained in food security of EU beef

Costs of compliance with EU regulations and competitiveness of the EU dairy sector

The introduction of cross-compliance mechanism in the European Union with its 2003 CAPreform might affect the costs of production and thus competitiveness of the EU. Little evidence is available to asses the costs of compliance with regulations and it implication for trade. In this study a farm level competitiveness analysis of the impacts of the Nitrate Directive and the Identification & registration Directive focuses on the dairy sector in Germany, France, Italy, Netherlands and UK (within EU), and the US and New Zealand (outside EU). The findings from this study are integrated into a trade analysis which assesses the impact of compliance costs on competitiveness of the various trading nations in global trade. Representative farm studies were used as a basis for the cost increase calculations. Best-estimates of compliance are used from the existing literature and expert judgements. The negative impact of these measures (for nitrates, and animal identification and registration) on EU imports and exports are less than 3 percent. If a smaller increase in compliance takes place, these already relatively small trade impacts will be further diminished. When the standards for nitrate pollution taken by the US and New Zealand are taken into account along with full compliance assumption in all countries analysed, this would only slightly improve the EU exports. The trade impacts obtained when no changes are assumed to happen in key competitor countries can thus be argued as providing the upper bound of the likely trade impacts

Classical resolution of singularities in dilaton cosmologies

For models of dilaton-gravity with a possible exponential potential, such as the tensor-scalar sector of IIA supergravity, we show how cosmological solutions correspond to trajectories in a 2D Milne space (parametrized by the dilaton and the scale factor). Cosmological singularities correspond to points at which a trajectory meets the Milne horizon, but the trajectories can be smoothly continued through the horizon to an instanton solution of the Euclidean theory. We find some exact cosmology/instanton solutions that lift to black holes in one higher dimension. For one such solution, the singularities of a big crunch to big bang transition mediated by an instanton phase lift to the black hole and cosmological horizons of de Sitter Schwarzschild spacetimes.Comment: 24 pages, 2 figure