AN ANALYSIS OF THE YIELD-PRICE RISK ASSOCIATED WITH SPECIALTY CROPS

Specialty crops have been cited as means to diversify crop portfolios on the prairies. Lentils, a specialty crop, have high variability in yields and prices but are relatively uncorrelated with the yields and prices of other traditional Saskatchewan crops. In addition, yields and prices of lentils may be negatively correlated. These attributes have important but offsetting effects in crop portfolio selection. The objective of this article is to assess the relative profitability and riskiness of wheat and lentil rotations for a representative Saskatchewan farm and to select appropriate farmers who should consider production of lentils. The cumulative density function of net returns are simulated for both rotations assuming stochastic prices and yields. Stochastic dominance with respect to a function is used to identify the corresponding appropriate profile of agricultural producers for each crop rotation. The results indicate that lentils should be considered by a number of, but not all, Saskatchewan farmers.Crop Production/Industries, Risk and Uncertainty,

Selenoxopropadienylidene (CCCSe) as a bridging ligand

The reaction of [W(≡CC≡CSiMe3)(CO)2(Tp*)] (Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate) with [nBu4N]F and selenium in the presence of [RuCl(PPh3)2(η-C5H5)] affords a mixture of the tricarbido complex [WRu(μ-CCC)(CO)2(PPh3)2(η-C5H5)(Tp*)] and the selenoxopropadienylidene (C3Se) complex [WRu(μ-CCCSe)(CO)2(PPh3)2(η-C5H5)(Tp*)], both of which were structurally characterized. The formation of the bimetallic C3Se complex is consistent with the intermediacy of the salt [nBu4N] [W(≡CC≡CSe)(CO)2(Tp*)], which could be observed spectroscopically and computationally interrogated, but not yet isolated.This work was supported by the Australian Research Council (DP130102598 and DP110101611)

Probing the (H3-H4)(2) histone tetramer structure using pulsed EPR spectroscopy combined with site-directed spin labelling

The (H3-H4)2 histone tetramer forms the central core of nucleosomes and, as such, plays a prominent role in assembly, disassembly and positioning of nucleosomes. Despite its fundamental role in chromatin, the tetramer has received little structural investigation. Here, through the use of pulsed electron-electron double resonance spectroscopy coupled with site-directed spin labelling, we survey the structure of the tetramer in solution. We find that tetramer is structurally more heterogeneous on its own than when sequestered in the octamer or nucleosome. In particular, while the central region including the H3-H3′ interface retains a structure similar to that observed in nucleosomes, other regions such as the H3 αN helix display increased structural heterogeneity. Flexibility of the H3 αN helix in the free tetramer also illustrates the potential for post-translational modifications to alter the structure of this region and mediate interactions with histone chaperones. The approach described here promises to prove a powerful system for investigating the structure of additional assemblies of histones with other important factors in chromatin assembly/fluidity

Effects of hemodialysis on platelet-derived thrombospondin

Effects of hemodialysis on platelet-derived thrombospondin. The effects on platelet-derived thrombospondin (TSP) of hemodialysis with a cellulose membrane were studied in patients during routine hemodialysis and in normal subjects using an ex vivo model. Plasma and platelet-bound TSP were determined pre- and post-dialysis, in blood entering and leaving the dialyzer after 1, 3, 5, 15, and 30 minutes of dialysis, and in blood leaving the ex vivo module after 5, 10, 15, 20, and 25 minutes of perfusion. Plasma concentrations of β-thromboglobulin (βTG) and thromboxane B2 (TxB2), and platelet membrane expression of the α-granule protein GMP-140, were also measured. Significant increases in plasma concentrations of TSP and βTG occurred between the inlet and outlet of the dialyzer after 5,15, and 30 minutes of dialysis, accompanied by a slow, but significant, increase in their arterial plasma concentrations. In contrast, initiation of dialysis was associated with an immediate increase in plasma TxB2 concentration between the inlet and outlet of the dialyzer and an abrupt increase in arterial plasma TxB2 concentration which plateaued at 250% of the pre-dialysis value after five minutes. Transit of platelets through the dialyzer had no effect on platelet-membrane-associated TSP or GMP-140. Plasma TSP and 0TG concentrations at the outlet of the ex vivo module also increased significantly during perfusion, but plasma TSP concentrations were twofold greater than those during hemodialysis. In vitro stimulation of platelets with thrombin and immunoblotting studies of platelet release proteins showed reduced TSP release by platelets of hemodialysis patients. These data demonstrate that dialyzer-induced platelet activation results in TSP release, suggesting that TSP can be a useful marker of platelet activation during hemodialysis. However, platelets of hemodialysis patients have an impaired ability to release TSP, most probably due to a TSP storage pool deficiency

s-Process Studies: Exact Evaluation of an Exponential Distrubution of Exposures

We show that the solution of the s-process chain can be easily evaluated exactly if the seed nuclei have been irradiated with an exponential distribution of exposures. For the same distribution of exposures, the shape of the akNk curve past the last seed is independent of the distribution of seed nuclei. Evaluation of these results confirms the accuracy of the well-known CFHZ approximation

Carman G. Blough: His personality and formative years

The article briefly explores the personality and psychological makeup of Carman G. Blough and discusses some experiences during his formative years that made Blough the person he was

s-Process Studies: Xenon and Krypton Isotopic Abundances

We propose an analysis of the s-process contributions to the isotopes of xenon and krypton. The object is to aid studies of the possibility that meteorites may contain gas that was carried in presolar grains that were grown in stellar ejecta and that were not degassed prior to incorporation into parent bodies. That model suggests routine interstellar fractionation of s-isotopes from r-isotopes owing to differential incoporation into dust. We show that a deficiency of s-process nuclei cannot yield details of Xe-X, but the gross similarities are strong enough to lead one to think that such a deficiency may play a role in a more complicated explanation. We predict the existence of an s-rich complement somewhere if fractional separation of this type has played a role in Xe-X. We show that the analogous decomposition of krypton is more uncertain, and we call for measurements of neutron-capture cross sections to alleviate these uncertainties

On Emission Lines in the Cosmic Gamma-Ray Background

We calculate the composite spectrum of γ-rays resulting from the decay of 56Ni to 56Co to 56Fe throughout the history of the universe. The results for several cosmological models are presented and compared with the Apollo 15 measurements at low resolution of the cosmic background. The radioactivity background is a significant fraction of the total, and several of its features may be detectable