Virtual soil testing – what is it?

Non-Peer ReviewedCurrently only ten percent of the total arable land in western Canada is soil tested at best. The percentage of farmers that soil test on a yearly basis is even lower. Providing recommendations to the farming community for the non-tested land presents both a challenge and an opportunity. Virtual soil testing started as an idea to essentially utilize information collected from soil tested fields and provide more qualified recommendations for those fields that were not tested. Virtual soil testing (or VST®) is in essence a modeling technique that reverses the soil testing process, i.e., utilizes crop production characteristics in association with chemical tests to predict soil nutrient levels for a subsequent crop (Karamanos and Cannon 2002). It is based on the Fertility Analysis and Recommendations Management (F.A.R.M.) model (Kruger et al. 1994) that was developed by Henry (1990; 1991) and was subsequently adapted to Saskatchewan, Manitoba and Alberta conditions by Karamanos and Henry (1991) and Karamanos et al. (1992a,b), respectively. F.A.R.M. essentially recognizes three sources of nitrogen contributing to plant N uptake, namely, soil available as determined by soil testing, net mineralizable and fertilizer nitrogen. Target yields are based on moisture use efficiency crop production equations (Karamanos and Henry, 1991) and are estimated for 75, 50 and 25 percent probability of precipitation in a given Soil Climatic Zone (Meyers and Karamanos, 1997). Recommendations for the rest of nutrients are simply based on “available” nutrient ranges and are in table format. This system of recommendations was introduced in the Province of Saskatchewan in 1991 and is currently used by Enviro-Test Laboratories in all three Prairie Provinces. Development of the VST process required modifications in the F.A.R.M. model, especially in relation to the soil mineralization component. These modifications are discussed by Karamanos and Cannon (2002)

A unified approach of catastrophic events

Although there is an accumulated charge of theoretical, computational, and numerical work, like catastrophe theory, bifurcation theory, stochastic and deterministic chaos theory, there is an important feeling that these matters do not completely cover the physics of real catastrophic events. Recent studies have suggested that a large variety of complex processes, including earthquakes, heartbeats, and neuronal dynamics, exhibits statistical similarities. Here we are studying in terms of complexity and non linear techniques whether isomorphic signatures emerged indicating the transition from the normal state to the both geological and biological shocks. In the last 15 years, the study of Complex Systems has emerged as a recognized field in its own right, although a good definition of what a complex system is, actually is eluded. A basic reason for our interest in complexity is the striking similarity in behaviour close to irreversible phase transitions among systems that are otherwise quite different in nature. It is by now recognized that the pre-seismic electromagnetic time-series contain valuable information about the earthquake preparation process, which cannot be extracted without the use of important computational power, probably in connection with computer Algebra techniques. This paper presents an analysis, the aim of which is to indicate the approach of the global instability in the pre-focal area. Non-linear characteristics are studied by applying two techniques, namely the Correlation Dimension Estimation and the Approximate Entropy. These two non-linear techniques present coherent conclusions, and could cooperate with an independent fractal spectral analysis to provide a detection concerning the emergence of the nucleation phase of the impending catastrophic event. In the context of similar mathematical background, it would be interesting to augment this description of pre-seismic electromagnetic anomalies in order to cover biological crises, namely, epileptic seizure and heart failure

Effect of time and rate of application of anhydrous ammonia and urea with or without a nitrification inhibitor on the yield and quality of a barley-wheat-canola rotation

Non-Peer ReviewedA project was initiated in the fall of 2006 to compare the effect of early (mid-September) and late (mid to late October) fall, and spring application of anhydrous ammonia and urea on the yield of barley, wheat and canola in barley-wheat-canola-wheat rotation. The experiment now in its third year is being carried out in two locations (Watrous and Lake Lenore) and involves four rates of N (0, 30, 80 and 120 kg N ha-1) with or without treatment with a nitrification inhibitor (N-Serve) annually applied on the same plots and four replicates for a total of 39 treatments. Consistent significant differences in all six-site years were responses to N and anhydrous vs. urea, the latter being a result of the inefficiency of the low N rate (40 kg ha-1) when applied as anhydrous ammonia. Overall, there were no differences due to time of application

Expression and Localization of Glycosaminoglycans/Proteoglycan in Pterygium: An Immunohistochemical Study

Pterygium is a triangle-shaped fibrovascular hyperplasia of the bulbar conjunctiva on the cornea. The purpose of this study was to analyze Proteoglycans (PGs) by Immunohistochemistry (IHC) in pterygium tissues and to compare the results with normal conjunctiva. Twenty-four patients (14 males) undergoing primary pterygium excision and 17 healthy individuals (10 males), undergoing extracapsular cataract surgery, were included. Pterygium tissues and normal conjunctiva tissues were surgically removed. The tissue sections were fixed in 2% paraformaldehyde and incubated with monoclonal antibodies against PGs anti-mouse IgG. Immunohistochemical study showed stronger expression of keratan sulfate in the stroma of the pterygium compared to normal conjunctiva. An increased expression of heparan sulfate was observed in the epithelial layer and around the pterygium vessels. On the other hand, dermatan sulfate showed an increased expression and localization not only in the sub-epithelial area of the pterygium and normal conjunctiva, yet throughout the stroma of the pterygium. The differences in the expression and localization of the studied extracellular matrix proteoglycans in the pterygium tissue compared to normal conjunctiva may explain the tissue hyperplasia, structure, and the functional properties in pterygium

Endovascular Treatment of Popliteal Artery Aneurysms

AbstractObjective. To present the results of the endovascular treatment of popliteal artery aneurysms.Methods. From April 1999 to January 2002, 11 patients, aged 40–94 years, with 12 popliteal aneurysms were treated. Nine (75%) underwent an endoluminal repair, of whom three were done emergently due to a aneurysm rupture. Aneurysm diameter was 28–105 (mean 69) mm. A Hemobahn stent graft was inserted in six, Wallgraft in two and Passager in one case.Results. During a mean follow-up of 14 (3–31) months, four (44%) thromboses occurred: two in the early postoperative period (30 days) and two during the late postoperative period. Two of the four occluded grafts were successfully reopened, and in the one a stenosis of the distal end of the stent graft was treated with balloon dilatation. Patency rates at 1 and 12 months were 64/47% (primary patency) and 88/75% (secondary patency), respectively.Conclusion. Initial experience with endovascular treatment of the popliteal aneurysm in high-risk patients yielded modest results. Larger number of patients and further follow-up time is necessary to evaluate the long-term results