LONG-TERM PROJECTIONS OF CHINA'S SUPPLY AND DEMAND OF ANIMAL FEEDSTUFFS

This paper was presented at the INTERNATIONAL TRADE IN LIVESTOCK PRODUCTS SYMPOSIUM in Auckland, New Zealand, January 18-19, 2001. The Symposium was sponsored by: the International Agricultural Trade Research Consortium, the Venture Trust, Massey University, New Zealand, and the Centre for Applied Economics and Policy Studies, Massey University. Dietary changes, especially in developing countries, are driving a massive increase in demand for livestock products. The objective of this symposium was to examine the consequences of this phenomenon, which some have even called a "revolution." How are dietary patterns changing, and can increased demands for livestock products be satisfied from domestic resources? If so, at what cost? What will be the flow-on impacts, for example, in terms of increased demands for feedgrains and the pressures for change within marketing systems? A supply-side response has been the continued development of large-scale, urban-based industrial livestock production systems that in many cases give rise to environmental concerns. If additional imports seem required, where will they originate and what about food security in the importing regions? How might market access conditions be re-negotiated to make increased imports achievable? Other important issues discussed involved food safety, animal health and welfare and the adoption of biotechnology, and their interactions with the negotiation of reforms to domestic and trade policies. Individual papers from this conference are available on AgEcon Search. If you would like to see the complete agenda and set of papers from this conference, please visit the IATRC Symposium web page at: http://www1.umn.edu/iatrc.intro.htmDemand and Price Analysis, Production Economics,

Magnetic effects in heavy-ion collisions at intermediate energies

The time-evolution and space-distribution of internal electromagnetic fields in heavy-ion reactions at beam energies between 200 and 2000 MeV/nucleon are studied within an Isospin-dependent Boltzmann-Uhling-Uhlenbeck transport model IBUU11. While the magnetic field can reach about $7\times 10^{16}$ G which is significantly higher than the estimated surface magnetic field ($\sim 10^{15}$ G) of magnetars, it has almost no effect on nucleon observables as the Lorentz force is normally much weaker than the nuclear force. Very interestingly, however, the magnetic field generated by the projectile-like (target-like) spectator has a strong focusing/diverging effect on positive/negative pions at forward (backward) rapidities. Consequently, the differential $\pi^-/\pi^+$ ratio as a function of rapidity is significantly altered by the magnetic field while the total multiplicities of both positive and negative pions remain about the same. At beam energies above about 1 GeV/nucleon, while the integrated ratio of total $\pi^-$ to $\pi^+$ multiplicities is not, the differential $\pi^-/\pi^+$ ratio is sensitive to the density dependence of nuclear symmetry energy $E_{\rm{sym}}(\rho)$. Our findings suggest that magnetic effects should be carefully considered in future studies of using the differential $\pi^-/\pi^+$ ratio as a probe of the $E_{\rm{sym}}(\rho)$ at supra-saturation densities.Comment: 12 pages including 8 figures and 1 tabl

Three-way noiseless signal splitting in a parametric amplifier with quantum correlation

We demonstrate that a phase-insensitive parametric amplifier, coupled to a quantum correlated source, can be used as a quantum information tap for noiseless three-way signal splitting. We find that the output signals are amplified noiselessly in two of the three output ports while the other can more or less keep its original input size without adding noise. This scheme is able to cascade and scales up for efficient information distribution in an optical network. Furthermore, we find this scheme satisfies the criteria for a non-ideal quantum non-demolition (QND) measurement and thus can serve as a QND measurement device. With two readouts correlated to the input, we find this scheme also satisfies the criterion for sequential QND measurement