Physics in Ultra-strong Magnetic Fields

In magnetic fields stronger than B_Q = 4.4 X 10^13 Gauss, an electron's Landau excitation energy exceeds its rest energy. I review the physics of this strange regime and some of its implications for the crusts and magneto- spheres of neutron stars. In particular, I describe how ultra-strong fields >> render the vacuum birefringent and capable of distorting and magnifying images ("magnetic lensing"); >> change the self-energy of electrons: as B increases they are first slightly lighter than $m_e$, then slightly heavier; >> cause photons to rapidly split and merge with each other; >> distort atoms into long, thin cylinders and molecules into strong, polymer-like chains; >> enhance the pair density in thermal pair-photon gases; >> strongly suppress photon-electron scattering, and >> drive the vacuum itself unstable, at extremely large B. In a concluding section, I discuss recent observations of the spindown histories of soft gamma repeaters and anomalous X-ray pulsars. The magnetar model gives a promising framework for understanding these data.Comment: Review talk given at Fifth Huntsville Gamma-Ray Burst Symposium. 12 pages with 5 eps figure

Achieving food security in China: Implications of WTO accession

The results of a three-year study of the implications of China's accession to the WTO for its agricultural sector and policy options to maximise the benefits of the trade reforms are reported. The most important message from the study is that macro-economic and other non-agriculture specific policies can do much to improve the outcome for rural households and thereby improve food security. These policies include the promotion of urban development in inland areas and gradual reform of monetary policy. However, agricultural policies need further reform, including abandoning of price support and regional self-sufficiency policies, reform of monopolistic agricultural marketing and distribution activities, and reform of the state grain storage system. Hopefully, WTO membership will assist implementation of these reforms.Food Security and Poverty, International Development,

String Breaking in Four Dimensional Lattice QCD

Virtual quark pair screening leads to breaking of the string between fundamental representation quarks in QCD. For unquenched four dimensional lattice QCD, this (so far elusive) phenomenon is studied using the recently developed truncated determinant algorithm (TDA). The dynamical configurations were generated on an Athlon 650 MHz PC. Quark eigenmodes up to 420 MeV are included exactly in these TDA studies performed at low quark mass on large coarse (but O($a^2$) improved) lattices. A study of Wilson line correlators in Coulomb gauge extracted from an ensemble of 1000 two-flavor dynamical configurations reveals evidence for flattening of the string tension at distances R $\geq$ approximately 1 fm.Comment: 16 pages, 5 figures, Latex (deleted extraneous eps figure file

Agricultural and resource economics and economic development in Aboriginal communities

Economic development is seen as the best way for Aboriginal communities to improve their welfare and lessen the considerable disadvantages they suffer. Unfortunately, the economics profession has shown little interest in their plight. Agricultural and resource economists have much to offer in helping to foster economic development in Aboriginal communities throughout Australia. Suggestions are made as to various ways in which our particular interests and experiences can hopefully be applied.International Development, Resource /Energy Economics and Policy,

World food markets into the 21st century: commodity risk management policies

Recent concerns about future global food production seem poorly based. The rapid phase of growth in food consumption is over for most of the world's population because of increased incomes and, besides, population growth rates continue to slow. Thus, the rate of growth of food production needed in the future is much lower than it has been for the past 40 years. Production and price instability will continue, perhaps with lessened intensity because of reduced government intervention. With private agricultural interests now facing greater exposure to price and production risks, especially in developing countries, there needs to be greater emphasis on financial market instruments for managing these risks.International Relations/Trade,

A summary of results from solar monitoring rocket flights

Three rocket flights to measure the solar constant and provide calibration data for sensors aboard Nimbus 6, 7, and Solar Maximum Mission (SMM) spacecraft were accomplished. The values obtained by the rocket instruments for the solar constant in SI units are: 1367 w/sq m on 29 June 1976; 1372 w/sq m on 16 November 1978; and 1374 w/sq m on 22 May 1980. The uncertainty of the rocket measurements is + or - 0.5%. The values obtained by the Hickey-Frieden sensor on Nimbus 7 during the second and third flights was 1376 w/sq m. The value obtained by the Active Cavity Radiometer Model IV (ACR IV) on SMM during the flight was 1368 w/sq m

Radiation scales and the solar constant

Radiation measurement and solar constant determinatio

Improved Pseudofermion Approach for All-Point Propagators

Quark propagators with arbitrary sources and sinks can be obtained more efficiently using a pseudofermion method with a mode-shifted action. Mode-shifting solves the problem of critical slowing down (for light quarks) induced by low eigenmodes of the Dirac operator. The method allows the full physical content of every gauge configuration to be extracted, and should be especially helpful for unquenched QCD calculations. The method can be applied for all the conventional quark actions: Wilson, Sheikoleslami-Wohlert, Kogut-Susskind, as well as Ginsparg-Wilson compliant overlap actions. The statistical properties of the method are examined and examples of physical processes under study are presented.Comment: LateX, 26 pages, 10 eps figure