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Rapeseed is the oil-bearing seed from plants of the Brassica genus. It grows well in the cooler agricultural regions o f the world and for this reason has long been thought to be a promising crop for interior Alaska. Rapeseed has been grow n in India and China for thousands and in Europe for hundreds o f years (Bolton 1980). Its history in North America began in 1943 when a small quantity of seed was imported into Canada. In recent years, its production has been largely that from cultivars bred for production of seed low in erucic acid and glucosinolate content. Seed from these cultivars is referred to by the Canadian Rapeseed Industry as canola. Its qualities are desirable in the edible-oil market, the largest market for products from canola seed. Canada is now one of the world’s largest producers and is the world’s largest exporter o f rapeseed. The meal that remains after oil extraction is high in protein and is used as a supplement in livestock feeds. The whole seed can also be used as a feed supplement. Some cultivars o f rapeseed that are high in erucic acid are also grow n for use in plastics and industrial oils (Genser and Eskin 1979). In addition, forage rapeseed cultivars can be used as livestock pasture. Research concerning the production of rapeseed has been addressed by the Agricultural and Forestry Experiment Station (AFES) for several years. O f specific concern has been the selection of appropriate cultivars (Wooding et al. 1978), response to various nitrogen (N) rates, row spacings and seeding rates (Lewis and Knight 1987), performance in reduced-tillage systems in rotation with barley (Knight and Lewis 1986), the potential for frost seeding in late fall and early spring (Knight and Sparrow 1984) and response to boron (B) to enhance early seed ripening (Wooding 1985). In addition, in 1978 the Cooperative Extension Service (CES) began conducting seminars on production o f rapeseed for Alaskan farmers. In 1979 and 1980, CES employed Dr. J.L . Bolton, a rapeseed specialist from the University o f Alberta, in an extension capacity to give technical assistance to farmers on producing rapeseed (Bolton 1980)

The Impact of Isospin Breaking on the Distribution of Transition Probabilities

In the present paper we investigate the effect of symmetry breaking in the statistical distributions of reduced transition amplitudes and reduced transition probabilities. These quantities are easier to access experimentally than the components of the eigenvectors and were measured by Adams et al. for the electromagnetic transitions in ^{26}Al. We focus on isospin symmetry breaking described by a matrix model where both, the Hamiltonian and the electromagnetic operator, break the symmetry. The results show that for partial isospin conservation, the statistical distribution of the reduced transition probability can considerably deviate from the Porter-Thomas distribution.Comment: 16 pages, 8 figures, submitted to PR

Global observations of 2 day wave coupling to the diurnal tide in a high‐altitude forecast‐assimilation system

We examine wave components in a high-altitude forecast-assimilation system that arise from nonlinear interaction between the diurnal tide and the westward traveling quasi 2 day wave. The process yields a westward traveling “sum” wave with zonal wave number 4 and a period of 16 h, and an eastward traveling “difference” wave with zonal wave number 2 and a period of 2 days. While the eastward 2 day wave has been reported in satellite temperatures, the westward 16 h wave lies outside the Nyquist limits of resolution of twice daily local time satellite sampling. Hourly output from a high-altitude forecast-assimilation model is used to diagnose the nonlinear quadriad. A steady state primitive equation model forced by tide-2 day wave advection is used to intepret the nonlinear wave products. The westward 16 h wave maximizes in the midlatitude winter mesosphere and behaves like an inertia-gravity wave. The nonlinearly generated component of the eastward 2 day wave maximizes at high latitudes in the lower thermosphere, and only weakly penetrates to low latitudes. The 16 h and the eastward 2 day waves are of comparable amplitude and alias to the same apparent frequency when viewed from a satellite perspective

DT fusion neutron radiation strengthening of copper and niobium

The initial results of a comparative study of the radiation strengthening and damage structures produced in Cu and Nb by D-T fusion and fission reactor neutrons are described. The radiation strengthening produced by a given fluence of fusion neutrons above about 10$sup 17$n/cm$sup 2$ is equal to that produced by a fluence of fission reactor neutrons (E greater than 0.1 MeV) ten times as great. This difference is about twice as large as would be expected if the strengthening scaled with damage energy or dpa. Initial transmission electron microscopy observations of the damage structures in fusion and fission reactor neutron irradiated copper indicate that the same type of primary structural defects, vacancy and interstitial point defect clusters and small dislocation loops with a/3 (111) and a/2 (110) Burgers vectors, are produced in both cases. The difference in the radiation strengthening produced by fusion and fission reactor neutrons in Cu appears to result from a substantially greater rate of accumulation of damage, in the form of point defect clusters, during irradiation with fusion neutrons than during irradiation with fission reactor neutrons plus a significant difference in the size and spatial distributions of the damage clusters. (auth

Complex patterns of spontaneous initiations and terminations of reentrant circulation in a loop of cardiac tissue

A two-component model is developed that consists of a discrete loop of cardiac cells that circulates action potentials together with a cardiac pacing mechanism. Physiological properties of cells such as restitutions of refractoriness and of conduction velocity are given via experimentally measured functions. The dynamics of circulating pulses and their interactions with the pacer are regulated by two threshold relations. Patterns of spontaneous initiations and terminations of reentry (SITR) generated by this system are studied through numerical simulations and analytical observations. These patterns can be regular or irregular; causes of irregularities are identified as the threshold bistability of reentrant circulation (T-bistability) and in some cases, also phase-resetting interactions with the pacer.Comment: 27 pages, 10 figures, 61 references; A version of this paper (same results) is to appear in the Journal of Theoretical Biology; arXiv V2 adds helpful commments to facilitate reading and corrects minor errors in presentatio

Shortest Path Problems on a Polyhedral Surface

We develop algorithms to compute shortest path edge sequences, Voronoi diagrams, the Fréchet distance, and the diameter for a polyhedral surface

Collectivity Embedded in Complex Spectra of Finite Interacting Fermi Systems: Nuclear Example

The mechanism of collectivity coexisting with chaos in a finite system of strongly interacting fermions is investigated. The complex spectra are represented in the basis of two-particle two-hole states describing the nuclear double-charge exchange modes in $^{48}$Ca. An example of $J^{\pi}=0^-$ excitations shows that the residual interaction, which generically implies chaotic behavior, under certain specific and well identified conditions may create strong transitions, even much stronger than those corresponding to a pure mean-field picture. Such an effect results from correlations among the off-diagonal matrix elements, is connected with locally reduced density of states and a local minimum in the information entropy.Comment: 16 pages, LaTeX2e, REVTeX, 8 PostScript figures, to appear in Physical Review