219 research outputs found
Relationship of morphological traits and seed yield of plain rough fescue grass (Festuca hallii (Vasey) Piper) with different origins
Non-Peer ReviewedSeed production in plains rough fescue (Festuca hallii (Vasey) Piper) is infrequent and
unpredictable. The objective of this study was to compare seed yield of plain rough fescue collections and to determine correlation between phenotypic characteristics and seed yield. In 2006, a field nursery was established from 11 collections of plain rough fescue grass at the Semiarid Prairie Agricultural Research Centre near Swift Current (50°25' N, 107°44' W), Canada. Plot design was a randomized complete block design with three replications. Six phenotypic variables were measured in summer 2010. Seed yield varied among collection sites. Plant vigour rating (r=0.29, P<0.01) and number of reproductive tiller (r=0.47, P<0.01) were positively correlated to individual plant seed yield, while reproductive tiller height (r=-0.47, P<0.01) and crown width (r=0.62, P<0.01) were negatively correlated to seed yield. Individual plant biomass didn’t have any correlation with seed yield. Selecting vigorous individual plant with higher number of reproductive tillers may improve seed yield of rough fescue grass
An evaluation of seed drills with various openers for seeding winter wheat in southwest Saskatchewan
Non-Peer ReviewedFour seed drills were evaluated for seeding winter wheat in South West Saskatchewan. Furrow opener types were the Swift Current zero-till offset disc, an air-seeder with Dutch banding knives, the Swift Current zero-till hoe, and Versatile Noble zero-till hoe. Soil disturbance varies from least to greatest in order listed, however, sufficient stubble is retained with all openers to normally ensure winter survival and adequate plant stands. No yield differences were observed for plots seeded by the various drills on chemical fallow on a clay loam soil. There is a tendency for the zero-till disc to show better yield on stubble on a clay loam soil whereas a hoe opener tends to show better yields on stubble for a sandy loam soil. However, other factors such as weather between fall and spring, GSP and spring soil moisture interacting with plant densities appear to affect yields equally as great. More years of data are required to confirm these trends
Evaluation of perennial cereal rye longevity and forage production when harvested at different stages of maturities and under grazing
Non-Peer ReviewedPerennial Cereal Rye (PC rye) (Secale cereale) has been promoted as a highly productive perennial forage crop for hay/silage and grazing for dryland areas. However
earlier research done at Agriculture and Agri-Food Canada – Semiarid Prairie Agricultural Research Centre (AAFC-SPARC) have found that time of seeding and
defoliation on PC rye can greatly affect the number of plants surviving through the
winter. Current research at AAFC-SPARC indicated that the stage of harvest (preboot,
boot and flowering) does affect stand survival and that PC rye longevity is lower
(P<0.001) than other short lived forage species, such as, Dahurian wildrye and Slender
wheatgrass under irrigation or dryland. Grazing studies at AAFC-SPARC also observed
PC rye plant counts decline by over 48% after two years of moderate grazing at the boot to heading plant stage
Triple oxygen isotopic composition of the high-<sup>3</sup>He/<sup>4</sup>He mantle
Measurements of Xe isotope ratios in ocean island basalts (OIB) suggest that Earth’s mantle accreted heterogeneously, and that compositional remnants of accretion are sampled by modern, high-3He/4He OIB associated with the Icelandic and Samoan plumes. If so, the high-3He/4He source may also have a distinct oxygen isotopic composition from the rest of the mantle. Here, we test if the major elements of the high-3He/4He source preserve any evidence of heterogeneous accretion using measurements of three oxygen isotopes on olivine from a variety of high-3He/4He OIB locations. To high precision, the Δ17O value of high-3He/4He olivines from Hawaii, Pitcairn, Baffin Island and Samoa, are indistinguishable from bulk mantle olivine (Δ17OBulk Mantle − Δ17OHigh 3He/4He olivine = −0.002 ± 0.004 (2 × SEM)‰). Thus, there is no resolvable oxygen isotope evidence for heterogeneous accretion in the high-3He/4He source. Modelling of mixing processes indicates that if an early-forming, oxygen-isotope distinct mantle did exist, either the anomaly was extremely small, or the anomaly was homogenised away by later mantle convection.
The δ18O values of olivine with the highest 3He/4He ratios from a variety of OIB locations have a relatively uniform composition (∼5‰). This composition is intermediate to values associated with the depleted MORB mantle and the average mantle. Similarly, δ18O values of olivine from high-3He/4He OIB correlate with radiogenic isotope ratios of He, Sr, and Nd. Combined, this suggests that magmatic oxygen is sourced from the same mantle as other, more incompatible elements and that the intermediate δ18O value is a feature of the high-3He/4He mantle source. The processes responsible for the δ18O signature of high-3He/4He mantle are not certain, but δ18O–87Sr/86Sr correlations indicate that it may be connected to a predominance of a HIMU-like (high U/Pb) component or other moderate δ18O components recycled into the high-3He/4He source
Primordialists and Constructionists: a typology of theories of religion
This article adopts categories from nationalism theory to classify theories of religion. Primordialist explanations are grounded in evolutionary psychology and emphasize the innate human demand for religion. Primordialists predict that religion does not decline in the modern era but will endure in perpetuity. Constructionist theories argue that religious demand is a human construct. Modernity initially energizes religion, but subsequently undermines it. Unpacking these ideal types is necessary in order to describe actual theorists of religion. Three distinctions within primordialism and constructionism are relevant. Namely those distinguishing: a) materialist from symbolist forms of constructionism; b) theories of origins from those pertaining to the reproduction of religion; and c) within reproduction, between theories of religious persistence and secularization. This typology helps to make sense of theories of religion by classifying them on the basis of their causal mechanisms, chronology and effects. In so doing, it opens up new sightlines for theory and research
Comprehensive assessment of cytochromes P450 and transporter genetics with endoxifen concentration during tamoxifen treatment
Objectives Tamoxifen bioactivation to endoxifen is mediated primarily by CYP2D6; however, considerable variability remains unexplained. Our aim was to perform a comprehensive assessment of the effect of genetic variation in tamoxifen-relevant enzymes and transporters on steady-state endoxifen concentrations. Patients and methods Comprehensive genotyping of CYP enzymes and transporters was performed using the iPLEX ADME PGx Pro Panel in 302 tamoxifen-treated breast cancer patients. Predicted activity phenotype for 19 enzymes and transporters were analyzed for univariate association with endoxifen concentration, and then adjusted for CYP2D6 and clinical covariates. Results In univariate analysis, higher activity of CYP2C8 (regression β=0.22, P=0.020) and CYP2C9 (β=0.20, P=0.04), lower body weight (β=-0.014, P<0.0001), and endoxifen measurement during winter (each β< -0.39, P=0.002) were associated with higher endoxifen concentrations. After adjustment for the CYP2D6 diplotype, weight, and season, CYP2C9 remained significantly associated with higher concentrations (P=0.02), but only increased the overall model R2 by 1.3%. Conclusion Our results further support a minor contribution of CYP2C9 genetic variability toward steadystate endoxifen concentrations. Integration of clinician and genetic variables into individualized tamoxifen dosing algorithms would marginally improve their accuracy and potentially enhance tamoxifen treatment outcomes
Patients' Understanding of How Genotype Variation Affects Benefits of Tamoxifen Therapy for Breast Cancer
CYP2D6 is a critical enzyme in the metabolism of tamoxifen and potentially a key determinant in breast cancer outcomes. Our study examined patients' beliefs about how CYP2D6 genotype would affect their prognoses
Neuropathological Findings In Chronic Relapsing Experimental Allergic Neuritis Induced In The Lewis Rat By Inoculation With Intradural Root Myelin And Treatment With Low Dose Cyclosporin A
Experimental allergic neuritis (EAN) was induced in Lewis rats by inoculation with bovine intradural root myelin and adjuvants. Rats treated with subcutaneous cyclosporin A (CsA) (4mg/kg on 3 days per week from the day of inoculation until day 29) developed a chronic relapsing course. Tissues from the spinal cord, nerve roots, dorsal root ganglia and sciatic nerve of CsA-treated rats sampled during relapses and remissions were studied during or after episodes of acute EAN. Both control and CsA-treated animals studied in the first episode of EAN had evidence of inflammation and primary demyelination of the nerve roots and dorsal root ganglia. In control and CsA-treated animals in the second episode there was severe inflammation and demyelination and remyelination in the spinal nerves and sciatic nerves and dorsal columns of the spinal cord, particularly in later stages of the disease. In later episodes there was less inflammation, but there was continuing demyelination and onion bulbs were present. In animals sampled after recovery from chronic relapsing EAN onion bulbs were present. Occasional small onion bulbs were also observed in control animals that were inoculated with higher doses of myelin. Plasma cells were present in the inflammatory lesions of later episodes. Mast cells were also observed at different stages of the disease. We conclude that the CsA form of chronic relapsing EAN has clinical and pathological similarities with the human disease, chronic inflammatory demyelinating polyradiculoneuropathy
Scaling ozone responses of forest trees to the ecosystem level in a changing climate
Many uncertainties remain regarding how climate change will alter the structure and function of forest ecosystems. At the Aspen FACE experiment in northern Wisconsin, we are attempting to understand how an aspen/birch/maple forest ecosystem responds to long-term exposure to elevated carbon dioxide (CO 2 ) and ozone (O 3 ), alone and in combination, from establishment onward. We examine how O 3 affects the flow of carbon through the ecosystem from the leaf level through to the roots and into the soil micro-organisms in present and future atmospheric CO 2 conditions. We provide evidence of adverse effects of O 3 , with or without co-occurring elevated CO 2 , that cascade through the entire ecosystem impacting complex trophic interactions and food webs on all three species in the study: trembling aspen ( Populus tremuloides Michx . ), paper birch ( Betula papyrifera Marsh), and sugar maple ( Acer saccharum Marsh). Interestingly, the negative effect of O 3 on the growth of sugar maple did not become evident until 3 years into the study. The negative effect of O 3 effect was most noticeable on paper birch trees growing under elevated CO 2 . Our results demonstrate the importance of long-term studies to detect subtle effects of atmospheric change and of the need for studies of interacting stresses whose responses could not be predicted by studies of single factors. In biologically complex forest ecosystems, effects at one scale can be very different from those at another scale. For scaling purposes, then, linking process with canopy level models is essential if O 3 impacts are to be accurately predicted. Finally, we describe how outputs from our long-term multispecies Aspen FACE experiment are being used to develop simple, coupled models to estimate productivity gain/loss from changing O 3 .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72464/1/j.1365-3040.2005.01362.x.pd
Solving math problems: Where and why does the solution process go astray?
Wetensch. publicatieFaculteit der Sociale Wetenschappe
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