Timing of N application affects winter cereal production

Non-Peer Reviewe

Input level and crop diversity effects on nitrate-N, extractable P, aggregation, and organic C and N in soil after two 6-year crop rotation cycles

Non-Peer Reviewe

Evaluation of remote sensing approaches to monitor crop conditions under specific input levels and cropping diversity

Non-Peer ReviewedThis study was conducted as part of the Alternative Cropping Systems (ACS) study at Scott, Saskatchewan. The 18 year study was initiated in 1995 to evaluate the sustainability of nine arable crop production systems. The nine cropping systems, derived from combinations of three input levels (organic, reduced, and high) and three cropping diversity levels (low, diversified annual grains, and diversified annual perennials), were designed to monitor and assess alternative input use and cropping strategies for arable crop production on the Canadian Prairies. Field data including leaf area index (LAI) and spectral reflectance were collected three times during the growing season of 2003: early growing season (June), mid growing season (July) and late growing season (August). LAI was measured with an LAI-2000 plant canopy analyzer. The spectral measurements were made with a handheld ADS spectroradiometer, which covers wavelengths from 350 nm to 2500 nm with 2151 bands. Results showed that remote sensing can be used to indicate different crop conditions. The spectral and LAI differences among input levels were significant at early to mid growing seasons. Mid July was the best season and the red over near infrared spectral ratio as well as the normalized difference vegetation index based on these two bands were the best vegetation indices to use for crop vigor monitoring

Impact of crop management systems on Fusarium populations in spring wheat and barley on the Canadian prairies

Non-Peer Reviewe

Human antibodies induce arthritis in mice deficient in the low-affinity inhibitory IgG receptor FcγRIIB

Rheumatoid arthritis (RA) is a complex autoimmune disease with a poorly understood pathogenesis. The disease is associated with polyclonal B cell activation and the production of autoantibodies (autoAbs), but there is a longstanding controversy as to whether such Abs contribute to, or are secondary to, the pathogenesis of RA. To address the potential pathogenicity of human RA–associated Abs, we developed a passive transfer model involving mice deficient in the low-affinity inhibitory Fc receptor, FcγRIIB. We report that plasma or serum from patients with active RA can induce inflammation and histological lesions in FcγRIIB−/− mice consistent with arthritis, and that this pathogenic activity is caused by the immunoglobulin G–rich fraction. Our results suggest that humoral autoimmunity can contribute directly to autoimmune arthritis, and that FcγRIIB−/− mice are a promising model to evaluate the arthritogenic potential of human autoAbs

A re-appraisal of the reliability of the 20 m multi-stage shuttle run test

This is the author's PDF version of an article published in European journal of applied physiology in 2007. The original publication is available at www.springerlink.co

The Ontario Pharmacy Evidence Network Atlas of Smoking Cessation Services

Introduction Tobacco smoking is a significant public health concern. It is estimated that more than 40,000 deaths and $6.5 billion in direct health care costs are attributable to tobacco smoking in Canada each year. Individuals who smoke tobacco or who are exposed to second-hand smoke are at increased risk of respiratory disease, cardiovascular disease and cancer. It is well known that quitting smoking can improve immediate and long-term health, yet nicotine dependence is a significant barrier to smoking cessation. Multimodal approaches that include medication and counselling services promote successful smoking cessation

The polygenic nature of telomere length and the anti-ageing properties of lithium

Telomere length is a promising biomarker for age-related disease and a potential anti-ageing drug target. Here, we study the genetic architecture of telomere length and the repositioning potential of lithium as an anti-ageing medication. LD score regression applied to the largest telomere length genome-wide association study to-date, revealed SNP-chip heritability estimates of 7.29%, with polygenic risk scoring capturing 4.4% of the variance in telomere length in an independent cohort (p = 6.17 × 10-5). Gene-enrichment analysis identified 13 genes associated with telomere length, with the most significant being the leucine rich repeat gene, LRRC34 (p = 3.69 × 10-18). In the context of lithium, we confirm that chronic use in a sample of 384 bipolar disorder patients is associated with longer telomeres (p = 0.03). As complementary evidence, we studied three orthologs of telomere length regulators in a Caenorhabditis elegans model of lithium-induced extended longevity and found all transcripts to be affected post-treatment (p  0.05). Consequently, this suggests that lithium may be catalysing the activity of endogenous mechanisms that promote telomere lengthening, whereby its efficacy eventually becomes limited by each individual's inherent telomere maintenance capabilities. Our work indicates a potential use of polygenic risk scoring for the prediction of adult telomere length and consequently lithium's anti-ageing efficacy