Dairy productivity in the Waikato region, 1994-2007

The dairy industry is a major contributor to both the New Zealand economy as a whole and to the Waikato regional economy in particular. The industry is experiencing a period of considerable change, with increases in dairy conversion, increased intensification, and increasing use of nitrogen fertilisers, each of which has an associated environmental cost. In this paper the productivity performance of the mature dairy industry in the Waikato region is investigated, using panel data at the sub-regional level from 1994 to 2007. Overall we show that, under a range of specifications, productivity growth independent of increasing land use and herd numbers has been significantly below the four percent industry target. This suggests that, if the four percent goal were to be met in the absence of significant technological progress, further increases in fertiliser use, land use, and/or farming intensity would be required.Productivity, dairy industry, Waikato., Agricultural and Food Policy, Environmental Economics and Policy, Farm Management, Land Economics/Use, Productivity Analysis,

A Meaner King uses Biased Bases

The mean king problem is a quantum mechanical retrodiction problem, in which Alice has to name the outcome of an ideal measurement on a d-dimensional quantum system, made in one of (d+1) orthonormal bases, unknown to Alice at the time of the measurement. Alice has to make this retrodiction on the basis of the classical outcomes of a suitable control measurement including an entangled copy. We show that the existence of a strategy for Alice is equivalent to the existence of an overall joint probability distribution for (d+1) random variables, whose marginal pair distributions are fixed as the transition probability matrices of the given bases. In particular, for d=2 the problem is decided by John Bell's classic inequality for three dichotomic variables. For mutually unbiased bases in any dimension Alice has a strategy, but for randomly chosen bases the probability for that goes rapidly to zero with increasing d.Comment: 5 pages, 1 figur

Relaxed Bell inequalities and Kochen-Specker theorems

The combination of various physically plausible properties, such as no signaling, determinism, and experimental free will, is known to be incompatible with quantum correlations. Hence, these properties must be individually or jointly relaxed in any model of such correlations. The necessary degrees of relaxation are quantified here, via natural distance and information-theoretic measures. This allows quantitative comparisons between different models in terms of the resources, such as the number of bits, of randomness, communication, and/or correlation, that they require. For example, measurement dependence is a relatively strong resource for modeling singlet state correlations, with only 1/15 of one bit of correlation required between measurement settings and the underlying variable. It is shown how various 'relaxed' Bell inequalities may be obtained, which precisely specify the complementary degrees of relaxation required to model any given violation of a standard Bell inequality. The robustness of a class of Kochen-Specker theorems, to relaxation of measurement independence, is also investigated. It is shown that a theorem of Mermin remains valid unless measurement independence is relaxed by 1/3. The Conway-Kochen 'free will' theorem and a result of Hardy are less robust, failing if measurement independence is relaxed by only 6.5% and 4.5%, respectively. An appendix shows the existence of an outcome independent model is equivalent to the existence of a deterministic model.Comment: 19 pages (including 3 appendices); v3: minor clarifications, to appear in PR

C and N Abundances in Stars At the Base of the Red Giant Branch in M5

We present an analysis of a large sample of moderate resolution Keck LRIS spectra of subgiant (V \sim 17.2) and fainter stars in the Galactic globular cluster M5 (NGC 5904) with the goal of deriving C and N abundances. Star-to-star stochastic variations with significant range in both [C/Fe] and [N/Fe] are found at all luminosities extending to the bottom of the RGB at M_V \sim +3. Similar variations in CH appear to be present in the main sequence turnoff spectra. There is no sign of a change in the behavior of C and N with evolutionary stage over the full range in luminosity of the RGB and SGB. The C and N abundances appear strongly anti-correlated, as would be expected from the CN-cycle processing of stellar material. Yet the present stars are considerably fainter than the RGB bump, the point at which deep mixing is believed to set in. On this basis, while the observed abundance pattern is consistent with proton capture nucleosynthesis, we infer that the site of the reactions is likely not within the present sample, but rather in a population of more massive (2 -- 5 M(Sun)) now defunct stars. The range of variation of the N abundances is very large and the sum of C+N increases as C decreases. To reproduce this requires the incorporation not only of CN but also of ON-processed material. Furthermore, the existence of this correlation is quite difficult to reproduce with an external mechanism such as ``pollution'' with material processed in a more massive AGB star, which mechanism is fundamentally stochastic in nature. We therefore suggest that although the internal mixing hypothesis has serious flaws,new theoretical insights are needed and it should not be ruled out yet. (abridged)Comment: Slightly updated version to conform to that accepted by the A

Inferred Genetic Architecture Underlying Evolution in a Fossil Stickleback Lineage

Inferring the genetic architecture of evolution in the fossil record is difficult because genetic crosses are impossible, the acquisition of DNA is usually impossible and phenotype–genotype maps are rarely obvious. However, such inference is valuable because it reveals the genetic basis of microevolutionary change across many more generations than is possible in studies of extant taxa, thereby integrating microevolutionary process and macroevolutionary pattern. Here, we infer the genetic basis of pelvic skeleton reduction in Gasterosteus doryssus, a Miocene stickleback fish from a finely resolved stratigraphic sequence that spans nearly 17,000 years. Reduction in pelvic score, a categorical measure of pelvic structure, resulted primarily from reciprocal frequency changes of two discrete phenotypic classes. Pelvic vestiges also showed left-side larger asymmetry. These patterns implicate Pitx1, a large-effect gene whose deletion generates left-side larger asymmetry of pelvic vestiges in extant, closely related Gasterosteus aculeatus. In contrast, reductions in the length of the pelvic girdle and pelvic spines resulted from directional shifts of unimodal, continuous trait distributions, suggesting an additional suite of genes with minor, additive pelvic effects, again like G. aculeatus. Similar genetic architectures explain shared but phyletically independent patterns across 10 million years of stickleback evolution

On the multiplicity of the O-star Cyg OB2 #8A and its contribution to the gamma-ray source 3EG J2033+4118

We present the results of an intensive spectroscopic campaign in the optical waveband revealing that Cyg OB2 #8A is an O6 + O5.5 binary system with a period of about 21.9 d. Cyg OB2 #8A is a bright X-ray source, as well as a non-thermal radio emitter. We discuss the binarity of this star in the framework of a campaign devoted to the study of non-thermal emitters, from the radio waveband to gamma-rays. In this context, we attribute the non-thermal radio emission from this star to a population of relativistic electrons, accelerated by the shock of the wind-wind collision. These relativistic electrons could also be responsible for a putative gamma-ray emission through inverse Compton scattering of photospheric UV photons, thus contributing to the yet unidentified EGRET source 3EG J2033+4118.Comment: 8 pages, 4 figures, conference on "The Multiwavelength Approach to Gamma-Ray Sources", to appear in Ap&S

Collective excitation spectrum of a disordered Hubbard model

We study the collective excitation spectrum of a d=3 site-disordered Anderson-Hubbard model at half-filling, via a random-phase approximation (RPA) about broken-symmetry, inhomogeneous unrestricted Hartree-Fock (UHF) ground states. We focus in particular on the density and character of low-frequency collective excitations in the transverse spin channel. In the absence of disorder, these are found to be spin-wave-like for all but very weak interaction strengths, extending down to zero frequency and separated from a Stoner-like band, to which there is a gap. With disorder present, a prominent spin-wave-like band is found to persist over a wide region of the disorder-interaction phase plane in which the mean-field ground state is a disordered antiferromagnet, despite the closure of the UHF single-particle gap. Site resolution of the RPA excitations leads to a microscopic rationalization of the evolution of the spectrum with disorder and interaction strength, and enables the observed localization properties to be interpreted in terms of the fraction of strong local moments and their site-differential distribution.Comment: 25 pages (revtex), 9 postscript figure