523 research outputs found

    XCEED™ canola, introduction of the first herbicide tolerant Brassica juncea canola for western Canada

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    Non-Peer ReviewedCanola-quality Brassica juncea has been developed to provide a reliable method of producing canola in areas prone to heat and drought and where straight-cut combing is desirable. Conventional varieties have been available since 2002 and have been grown on a limited acreage. CLEARFIELD varieties have been developed and will provide improved weed control options for the crop and thereby increase the cultivated acreage. These varieties will be marketed as XCEED canola by Viterra

    Is a 20 Kg Load Sufficient to Simulate Fatigue in Squat Jumps?

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    Abstract available in the Annual Coaches and Sport Science College

    Seasonal Change in Countermovement Jump Performance in NCAA Women’s Golfers

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    Background of Study: The countermovement vertical jump (CMJ) task has been reported to have positive associations with golf-specific performance variables. Additionally, the CMJ is commonly used to assess neuromuscular fatigue in athletic populations. Objective: Thus, this investigation sought to examine the changes in CMJ performance throughout a competitive season in NCAA collegiate women’s golfers. Methods: Using a longitudinal study design, six collegiate women golfers completed three sessions (pre, mid, and post) of CMJ testing during the spring competition period. During each testing session, two successful jump trials were collected using a portable force platform sampling at 1000 Hz. During each trial, an arm swing was restricted by the use of a dowel placed across the upper back. A one-way repeated measures analysis of variance was used to determine if differences were present between testing sessions. Results: Propulsive net impulse significantly increased from pre to mid (p 0.05) and pre to post (p 0.05). No other variables showed a statistically significant change over the duration of the study, though moderate effect size increases were in countermovement depth from pre to mid-testing (0.73) and jump height from pre to post-testing (0.72). Conclusions: These findings support previous findings of an increase in vertical jump performance over the course of a season in collegiate golfers, though strategies for maximal performance may shift

    Gause's exclusion principle revisited: artificial modified species and competition

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    Gause's principle of competition between two species is studied when one of them is sterile. We study the condition for total extinction in the niche, namely, when the sterile population exterminates the native one by an optimal use of resources. A mathematical Lotka-Volterra non linear model of interaction between a native and sterile species is proposed. The condition for total extinction is related to the initial number MoM_{o} of sterile individuals released in the niche. In fact, the existence of a critical sterile-population value McM_{c} is conjectured from numerical analysis and an analytical estimation is found. When spatial diffusion (migration) is considered a critical size territory is found and, for small territory, total extinction exist in any case. This work is motived by the extermination agriculture problem of fruit flies in our region.Comment: 11 pages. Published in Jour.Phys.A Math.Gen. 33, 4877 (2000

    Enhancing the early student experience

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    This paper is concerned with identifying how the early student experience can be enhanced in order to improve levels of student retention and achievement. The early student experience is the focus of this project as the literature has consistently declared the first year to be the most critical in shaping persistence decisions. Programme managers of courses with high and low retention rates have been interviewed to identify activities that appear to be associated with good retention rates. The results show that there are similarities in the way programmes with high retention are run, with these features not being prevalent on programmes with low retention. Recommendations of activities that appear likely to enhance the early student experience are provided

    Optimum dose of ginger root oil to treat sterile Mediterranean fruit fly males (Diptera: Tephritidae)

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    The sterile insect technique (SIT) is widely used as part of an integrated approach to reduce field populations of the Mediterranean fruit fly (Ceratitis capitata, Diptera: Tephritidae). Aromatherapy based on exposure to ginger root oil (GRO) volatiles is known as a method to significantly improve the sexual performance of sterile medfly males, and is being used in many mass-rearing facilities around the world. However, the optimum dose of GRO is not well defined. This work evaluated in laboratory cages four different doses of GRO and a control (0, 0.1, 0.25, 0.5 and 0.75 ml/m3), and two different methods to hold flies prior to release (paper bags and plastic cages). The objective was to find the lowest dose that provides optimal improvement in mating performance of sterile males when competing with wild males for wild females and optimal reduction in fertility of wild females. Egg hatch, copula duration, the Relative Sterility Index (RSI), and a Competitiveness (C) value (based on RSI) were calculated for each treatment to assess male sexual performance and induction of sterility. The method used to hold flies did not influence the aromatherapy effect. The mean time spent by wild females in copula with wild males was significantly longer than with sterile males for all treatments, except when sterile males were treated with 0.1 ml of GRO/m3. Amongst all doses studied, it is recommended to apply the lowest dose, 0.1 ml of GRO/m3, since at this dose both the RSI and induced sterility reached the highest levels, and were not statistically different from the 0.25 and 0.5 GRO/m3 doses. Indeed, this dose showed a very significant improvement in the mating competitiveness of sterile males aromatically treated with GRO.Supplement 1

    Evaluation of Readmission Ink as a Marker for Dispersal Studies with the Oriental Fruit Fly, Bactrocera dorsalis

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    In this text we present a new marking dye, readmission ink, Blak-Ray, for the purpose of insect movement studies. The dye was tested in a controlled experiment with Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) in anticipation of a long distance movement study planned for the following year with the same species. 700 individuals of both sexes were marked with the dye and placed in holding containers. Both the percentage of mortality and the ease of dye detection were monitored throughout a five-week period. Results showed minimal fly mortality and exceptional ease of dye detection
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