Randomized, double-blind comparison of patient-controlled epidural infusion vs nurse-administered epidural infusion for postoperative analgesia in patients undergoing colonic resection

Background. There is little published evidence of the analgesic efficacy of patient-controlled epidural analgesia (PCEA) for postoperative pain relief. The aim of this study was to compare the analgesic efficacy of epidural infusion of bupivacaine 0.125% and fentanyl 4 μg ml-1 administered by either PCEA with a background infusion or nurse-administered continuous epidural infusion (CEI) after major intra-abdominal surgery. Methods. In a double-blind, randomized clinical trial, 205 adult patients undergoing colonic resection by laparotomy received either PCEA or CEI. Pain scores were recorded via a fourpoint verbal rating scale at 1, 2, 3, 4, 8, 12, 24, 48, and 72 h after surgery. The administration of epidural top-ups and systemic analgesia over the same period was also recorded, and patient satisfaction questionnaires completed. Results. The median area under the curve of pain against time was significantly lower in the PCEA group (2 vs 24, P<0.001) as were median summary pain scores on movement (0.67 vs 1.33, P<0.001). Significantly fewer patients in the PCEA group received one or more epidural top-ups (13 vs 36%, P=0.0002) or any systemic analgesics (41 vs 63%, P=0.0021). Patients in the PCEA group were significantly more likely to be very satisfied than in the CEI group (76 vs 43%, P<0.0001). Conclusions. PCEA provides greater analgesic efficacy than CEI for postoperative analgesia after major intra-abdominal surgery, and a decreased requirement for physician or nurse intervention

Effects of novel non-bloat legumes on C and N pools in pasture systems

Non-Peer ReviewedImproved pasture systems have the potential to reduce greenhouse gas (GHG) emissions and enhance soil organic carbon (SOC) to mitigate climate change. However, with intensive grazing, pastures can lose a considerable percentage of stored SOC because of lowered primary production and increased soil erosion. Degraded pastures with N-limited soils can be regenerated either through fertilization at soil-test recommended rates or inclusion of legume species such as alfalfa. Despite the predominant use of alfalfa in pasture regeneration within North America, its economic benefits for cattle are not fully realized because of frothy bloat leading to the inefficient use of its protein value. Therefore there is a renewed interest in novel non-bloat legumes such as Sainfoin and Cicer Milkvetch as alternatives. In spite of the successful use of Sainfoin and Cicer Milkvetch in pasture regeneration, their impacts on SOC and C sequestration have not been determined. The objective of this study as part of a broader study was to determine the effects of novel non-bloat legumes inclusion using the sod-seeded technique on labile and bulk C and N pools. The study hypothesized that; the inclusion of novel non-bloat legumes with different N2-fixation and photosynthetic capabilities in pasture systems could increase both labile and bulk C and N pools due to increased soil organic matter content and microbial population. After two years of incorporating non-bloat legumes in pasture systems, preliminary results showed SOC was significantly (P <.0001) higher on the upper slope compared to the lower slope position. The system can store between 45.1 ±5.47 to 75.7 ±4.21 Mg C ha-1, in the lower and upper slope positions, respectively, up to 1 m soil depth, with 50% of the SOC within the top 0-30 cm soil depth. Light fraction organic C and N, and dissolved organic C and total N followed the same trend as the SOC with upper slope position recording higher values compared to lower slope position. Baseline soil nutrients also proved that the pasture system has a closed nutrient cycling. Finally, irrespective of the legume species or cultivars, the C: N ratio is close to 10:1, suggesting a dynamic equilibrium may be due to the dominating presence of a microbial population. The closed nutrient cycling and the near equilibrium C: N ratio shows that after two years of pasture rejuvenation, the inclusion of non-bloat legumes using the sod-seeded technique has the potential to improve forage quality and reduce GHG emission footprint of pasture systems. Results would add to that of a broader study and would be beneficial to producers and policymakers within Canada and beyond for C accounting and credit purposes

Phytoremediation of hydrocarbon-contaminated soil using native plants

Non-Peer ReviewedPhytoremediation of hydrocarbon-contaminated soil involves plants and their associated microorganisms. However, few cold-tolerant plants have been identified for reclamation in the native grasslands and woodlands of Canada. We assessed 35 native grasses, legumes and forbs, and seven exotic grasses and legumes for their ability to germinate and survive in crude oil contaminated soil. Based on germination, survival, growth rate, and above and below ground biomass five native (Artemisia frigida, Bromus ciliatus, Glycyrrhiza lepidota, Potentilla pensylvanica, and Psoralea esculenta) and three exotic (Medicago sativa, Melilotus officinalis and Trifolium repens) plants exhibited phytoremediation potential. The ability of these species to degrade specific hydrocarbons and mixtures of hydrocarbons is currently being assessed

Potassium, sulfur, zinc, copper, and iron uptake by four faba bean cultivars at four sites in Saskatchewan

Non-Peer Reviewe

Effect of an immunisation campaign in Natal and KwaZulu on vaccination coverage rates, 1990 - 1991

No Abstract

Linear response of vibrated granular systems to sudden changes in the vibration intensity

The short-term memory effects recently observed in vibration-induced compaction of granular materials are studied. It is shown that they can be explained by means of quite plausible hypothesis about the mesoscopic description of the evolution of the system. The existence of a critical time separating regimes of ``anomalous'' and ``normal'' responses is predicted. A simple model fitting into the general framework is analyzed in the detail. The relationship between this work and previous studies is discussed.Comment: 10 pages, 6 figures; fixed errata, updtated reference

NMR Experiments on a Three-Dimensional Vibrofluidized Granular Medium

A three-dimensional granular system fluidized by vertical container vibrations was studied using pulsed field gradient (PFG) NMR coupled with one-dimensional magnetic resonance imaging (MRI). The system consisted of mustard seeds vibrated vertically at 50 Hz, and the number of layers N_ell <= 4 was sufficiently low to achieve a nearly time-independent granular fluid. Using NMR, the vertical profiles of density and granular temperature were directly measured, along with the distributions of vertical and horizontal grain velocities. The velocity distributions showed modest deviations from Maxwell-Boltzmann statistics, except for the vertical velocity distribution near the sample bottom which was highly skewed and non-Gaussian. Data taken for three values of N_ell and two dimensionless accelerations Gamma=15,18 were fit to a hydrodynamic theory, which successfully models the density and temperature profiles including a temperature inversion near the free upper surface.Comment: 14 pages, 15 figure

Thermodynamics and statistical mechanics of frozen systems in inherent states

We discuss a Statistical Mechanics approach in the manner of Edwards to the ``inherent states'' (defined as the stable configurations in the potential energy landscape) of glassy systems and granular materials. We show that at stationarity the inherent states are distributed according a generalized Gibbs measure obtained assuming the validity of the principle of maximum entropy, under suitable constraints. In particular we consider three lattice models (a diluted Spin Glass, a monodisperse hard-sphere system under gravity and a hard-sphere binary mixture under gravity) undergoing a schematic ``tap dynamics'', showing via Monte Carlo calculations that the time average of macroscopic quantities over the tap dynamics and over such a generalized distribution coincide. We also discuss about the general validity of this approach to non thermal systems.Comment: 10 pages, 16 figure

Segregation by thermal diffusion of an intruder in a moderately dense granular fluid

A solution of the inelastic Enskog equation that goes beyond the weak dissipation limit and applies for moderate densities is used to determine the thermal diffusion factor of an intruder immersed in a dense granular gas under gravity. This factor provides a segregation criterion that shows the transition between the Brazil-nut effect (BNE) and the reverse Brazil-nut effect (RBNE) by varying the parameters of the system (masses, sizes, density and coefficients of restitution). The form of the phase-diagrams for the BNE/RBNE transition depends sensitively on the value of gravity relative to the thermal gradient, so that it is possible to switch between both states for given values of the parameters of the system. Two specific limits are considered with detail: (i) absence of gravity, and (ii) homogeneous temperature. In the latter case, after some approximations, our results are consistent with previous theoretical results derived from the Enskog equation. Our results also indicate that the influence of dissipation on thermal diffusion is more important in the absence of gravity than in the opposite limit. The present analysis extends previous theoretical results derived in the dilute limit case [V. Garz\'o, Europhys. Lett. {\bf 75}, 521 (2006)] and is consistent with the findings of some recent experimental results.Comment: 10 figure

Slow relaxation due to optimization and restructuring: Solution on a hierarchical lattice

Motivated by the large strain shear of loose granular materials we introduced a model which consists of consecutive optimization and restructuring steps leading to a self organization of a density field. The extensive connections to other models of statistical phyics are discussed. We investigate our model on a hierarchical lattice which allows an exact asymptotic renormalization treatment. A surprisingly close analogy is observed between the simulation results on the regular and the hierarchical lattices. The dynamics is characterized by the breakdown of ergodicity, by unusual system size effects in the development of the average density as well as by the age distribution, the latter showing multifractal properties.Comment: 11 pages, 7 figures revtex, submitted to PRE see also: cond-mat/020920