Prairie Crop Diversification

The Canadian prairies traditionally have been dominated by spring wheat production. Crop diversification is now being advocated to enhance farm-level risk management, ecological benefits, nutrient cycling, and pest and disease control, and to reduce the farm economy’s reliance on income from a single crop. There has always been interest in diversifying away from wheat, but until recently, economically feasible alternatives have been limited, and government policies may have constrained the shift to other crops. Knowing the impact of prices and policies on crop diversification is essential to understanding producer response and to determining strategies to enhance cropping diversity.Marketing,

Ketorolac Use and Incidence of Postoperative Bleeding in an ERAS Colorectal Surgical Population: A Quality Analysis of Practice

Background Ketorolac is an effective analgesic adjunct and is currently used in Enhanced Recovery After Surgery (ERAS) protocols. However, investigation into its safety profile is warranted in specific surgical populations. This Quality Improvement (QI) study sought to examine the association of ketorolac to increased postoperative bleeding risk, increased postoperative renal impairment, and 30-day readmission within an ERAS protocol for colorectal surgery. Methods A retrospective review was conducted of 158 patients enrolled in an existing ERAS protocol for colorectal surgery with at least one dose of ketorolac administered in the perioperative period. Outcomes of postoperative bleeding, 30-day readmission, and preoperative/postoperative serum creatinine levels were assessed. Results There was no statistically significant difference in the incidence of postoperative bleeding compared to a known population. There was a significant association of 30-day readmissions with documented evidence of bleeding (P = 0.037). There was no significant change in the preoperative and postoperative serum creatinine. Multivariate logistic regression analysis found no association of postoperative bleeding with pre-existing chronic non-steroidal anti-inflammatory drug (NSAID) use or preoperative serum creatinine. Conclusions Ketorolac is not associated with an increased risk of postoperative bleeding in colorectal ERAS surgical patients. However, postoperative bleeding does predict the likelihood for 30-day readmissions

Previous Grass-Lucerne Mixtures Affect Barley Yield and Quality in a Semiarid Location of the Canadian Prairie Region

In the semiarid region of the Canadian prairies perennial forages are not rotated with annual crops because previous experiments reported negative impacts (Kilcher and Anderson 1963; Campbell et al. 1990). However, previous research used persistent species while short-lived species could have less adverse effect. Our objective was to compare three grass species in three lucerne mixtures terminated with tillage or herbicide for effects on barley grain, N concentration, and N uptake

Effect of crop rotations on soil organic matter in two Black Chernozems

Non-Peer Reviewe

Bailing Out the Milky Way: Variation in the Properties of Massive Dwarfs Among Galaxy-Sized Systems

Recent kinematical constraints on the internal densities of the Milky Way's dwarf satellites have revealed a discrepancy with the subhalo populations of simulated Galaxy-scale halos in the standard CDM model of hierarchical structure formation. This has been dubbed the "too big to fail" problem, with reference to the improbability of large and invisible companions existing in the Galactic environment. In this paper, we argue that both the Milky Way observations and simulated subhalos are consistent with the predictions of the standard model for structure formation. Specifically, we show that there is significant variation in the properties of subhalos among distinct host halos of fixed mass and suggest that this can reasonably account for the deficit of dense satellites in the Milky Way. We exploit well-tested analytic techniques to predict the properties in a large sample of distinct host halos with a variety of masses spanning the range expected of the Galactic halo. The analytic model produces subhalo populations consistent with both Via Lactea II and Aquarius, and our results suggest that natural variation in subhalo properties suffices to explain the discrepancy between Milky Way satellite kinematics and these numerical simulations. At least ~10% of Milky Way-sized halos host subhalo populations for which there is no "too big to fail" problem, even when the host halo mass is as large as M_host = 10^12.2 h^-1 M_sun. Follow-up studies consisting of high-resolution simulations of a large number of Milky Way-sized hosts are necessary to confirm our predictions. In the absence of such efforts, the "too big to fail" problem does not appear to be a significant challenge to the standard model of hierarchical formation. [abridged]Comment: 12 pages, 3 figures; accepted by JCAP. Replaced with published versio

Statistics of Magnification Perturbations by Substructure in the Cold Dark Matter Cosmological Model

We study the statistical properties of magnification perturbations by substructures in strong lensed systems using linear perturbation theory and an analytical substructure model including tidal truncation and a continuous substructure mass spectrum. We demonstrate that magnification perturbations are dominated by perturbers found within a tidal radius of an image, and that sizable magnification perturbations may arise from small, coherent contributions from several substructures within the lens halo. We find that the root-mean-square (rms) fluctuation of the magnification perturbation is 10% to 20% and both the average and rms perturbations are sensitive to the mass spectrum and density profile of the perturbers. Interestingly, we find that relative to a smooth model of the same mass, the average magnification in clumpy models is lower (higher) than that in smooth models for positive (negative) parity images. This is opposite from what is observed if one assumes that the image magnification predicted by the best-fit smooth model of a lens is a good proxy for what the observed magnification would have been if substructures were absent. While it is possible for this discrepancy to be resolved via nonlinear perturbers, we argue that a more likely explanation is that the assumption that the best-fit lens model is a good proxy for the magnification in the absence of substructure is not correct. We conclude that a better theoretical understanding of the predicted statistical properties of magnification perturbations by CDM substructure is needed in order to affirm that CDM substructures have been unambiguously detected.Comment: ApJ accepted, minor change