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Harvey S. J. Hill Graduate Research Assistant Jaehong Park Graduate Research Assistant James W. Mjelde Professor Wesley Rosenthal Assistant Professor H. Alan Love Associate Professor Stephen W. Fuller Professor 《Agricultural and Forest Meteorology》2000,100(4)
Southern Oscillation Index (SOI) based forecasting methods are compared to determine which method is more valuable to Canadian and US wheat producers. Using decision theory approach to valuing information, the more commonly used three-phase method of El Niño, La Niña, and other is compared to a five-phase system. Because of differences in growing season and yearly SOI classification schemes, two different three-phase methods are used. The five-phase system is based on the level and rate of change of the SOI over a 2 month period. Phases are consistently negative, consistently positive, rapidly falling, rapidly rising, and near zero. As expected, results vary by the method used. Winter wheat producers in Illinois place no value on either of the SOI-based forecasting systems. Producers at seven of the 13 sites prefer the five-phase method over either of the three-phase method (spring wheat producers in Manitoba, Alberta, North Dakota and South Dakota, along with winter wheat producers in Oklahoma, Texas, and Washington). The value of the five-phase approach is up to 70 times more valuable than the three-phase approach. Producers growing spring wheat in Saskatchewan and Montana, along with winter wheat producers in Ohio and Kansas value the three-phase approach more than the five-phase. In this case, the value of the three-phase system is up to two times more valuable than the five-phase system. Depending on expected price and region, the values of the SOI-based forecasts range from 0 to 22% of the value of perfect forecasts. In both absolute and percentage of perfect forecasts, producers in Oklahoma, Texas, Manitoba, Saskatchewan, and South Dakota value either system more than producers in the remaining regions. Economic value and distributional aspects of the value of climate forecasts have implications for producers, policy makers, and meteorologists. Finally, the results clearly suggest all producers will not prefer one forecast type. Forecasts need to be tailored to specific regions. 相似文献
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Vishalakshi Iyer Professor D. K. Salunkhe S. K. Sathe Louis B. Rockland 《Plant foods for human nutrition (Dordrecht, Netherlands)》1980,30(1):27-43
Soaking three beans cultivars (Phaseolus vulgaris L.: Great Northern, kidney, and pinto) in mixed salt solution (sodium chloride 2.5% + sodium bicarbonate 1.5% + sodium tripolyphosphate 1.0% + sodium carbonate 0.5%) resulted in 80%–85% reduction in cooking time over corresponding controls. Irradiation (-rays) at 500 krads of soaked and dehydrated beans caused a reduction of nearly 50% in cooking time. Water uptake and leaching losses for each treatment during soaking at 22°, 37°, and 45°C were investigated. High temperature (37° and 45°C) and pH (9.0) caused greater water imbibition and total solid loss than at room temperature (22°C). Organoleptic evaluation revealed that quick-cooking Great Northern beans appear to be more acceptable than kidney and pinto beans. Quick-cooking cooked beans had better in vitro protein digestibility than conventionally cooked beans. Phenolic content was found to be inversely related to in vitro digestibility.Utah Agricultural Experiment Station Journal article no. 2481. 相似文献
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Effects of cortisol on growth and development in tilapia larvae,Oreochromis mossambicus 总被引:1,自引:0,他引:1
A. Mathiyalagan P. K. Reddy Professor T. J. Lam 《Fish physiology and biochemistry》1996,15(6):453-458
Treatment of one-day-old yolksac larvae of tilapia (Oreochromis mossambicus), by immersion in cortisol solution for two weeks, significantly enhanced growth. The standard length, tail length, head width and wet weight showed dose-dependent increases at concentrations of cortisol (hydrocortisone) from 0.05 ppm to 0.5 ppm, with no further increase at 1.0 ppm. However, cortisol at 5.0 ppm retarded the growth of the larvae without causing any morphological abnormality. Yolk absorption and the onset of free-swimming activity in the larvae were also accelerated by cortisol treatment. 相似文献
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Professor R. R. Archer 《Wood Science and Technology》1976,10(4):293-309
Summary A plane strain pure bending model is used to predict stress states in a transversely isotropic cylinder due to asymmetric strain distributions continuously induced at the periphery. A general solution for the stress states related to each component of the strain distribution expanded in a Fourier series is given. An expression for the change of curvature due to each new growth increment is derived.This work was supported in part by NSF Grant ENG 74-02428. 相似文献
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Summary It is frequently the case that multiple strength properties of structural wood members are simultaneously needed in design or research. A method has been developed to predict the probability distribution of concomitant material properties of wood from a knowledge of some correlated, nondestructive material property. The method developed in this study is based on properties of the univariate SB distribution and the bivariate SBB distribution. The technique involves a priori knowledge of the correlation relationship between a nondestructive parameter and the strength parameter for the two concomitant properties in question. A relationship is developed between the two nondestructive parameters and a simulation procedure is presented to predict either concomitant property from a single nondestructive measurement. The results showed that when a single parameter was predicted directly from a correlated variable, the simulated and experimental distributions were very similar (average error 3–4%). This result confirms previous findings. For the prediction of the concomitant property from an indirect relationship with another parameter, the absolute value of the average error was about 13%. 相似文献
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Charles F. Yamoah Professor of Plant Sciences James R. Burleigh 《Agroforestry Systems》1990,10(2):169-181
Food production in the densely populated Rwandan highlands is impeded by soil erosion and loss in fertility. Alley cropping
leguminous shrubs with food crops on contours is purported to minimize the problem and to provide wood and forage. This study
reports the effect of Sesbania prunings plus moderate levels of N and P on bean (Phaseolus sp) and maize (Zea mays) yields in alley cropping. Experimental design was a randomized complete block with split-split plots. Main plots were alley
width: 2, 4, 6 and 8 m. Phosphorus (P) at 0, 30 and 60 kg P2O5/ha occupied the subplot and nitrogen (N) at 0, 30 and 60 kg/ha were assigned at the sub-sub plot level. No P was applied
to maize during the second cropping season. Crop yield in kg/ha included the land space taken by hedgerows. Bean yield in
6 m alleys (1100 kg/ha) was about twice that in 2 m alleys (500 kg/ha). Bean responded to N and P. Optimum alley width and
N for bean yield were 6 m and 30 kg/ha, respectively. Cuttings from alley hedgerows provided stakes for climbing beans. Maize
responded to N but not to residual P. The highest maize yield came from 8 m alleys with 40 kg/ha, but yields from 8 and 6
m alleys with the same N treatment were not significantly different. Maize plants in middle rows were significantly taller
than plants in rows adjacent to hedgerows. Maize rust development showed significant alley width and row position effect.
There were significantly fewer uredinia in the Sebania alleys relative to the control plots without shrub hedgerows. Rust development on maize in middle rows was significantly
greater than development in border rows. 相似文献