2,708 research outputs found

    Crop Yields as related to Depth of Plowing

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    Destroy the Common Barberry Bush

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    Why the Common Barberry Must Be Destroyed. It harbors and propagates black stem rust of wheat and other grains. It is a patriotic duty of every one in the state who owns even one bush of the common barberry to dig it out and destroy it and thereby help save the millions of bushels of wheat which are annually destroyed by rust

    Depth of Plowing and Crop Yields

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    Twenty-One Years of Crop Yields from Cottonwood Experiment Farm

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    Interpreting New Data on Large Scale Bulk Flows

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    We study the implications of a recent estimate of the bulk flow of a sample of galaxies containing supernovae type Ia by Riess, Press, and Kirshner. We find that their results are quite consistent with power spectra from several currently popular models of structure formation, but that the sample is as yet too sparse to put significant constraints on the power spectrum. We compare this new result with that of Lauer and Postman, with which there is apparent disagreement. We find that for the power spectra we consider, the difference in window functions between the two samples used for the measurements results in a low level of expected correlation between the estimated bulk flows. We calculate a χ2\chi^2 for the two measurements taken together and find that their lack of agreement tends to disfavor spectra with excessive power on large scales, but not at a level sufficient to rule them out. A sample consisting of other SN type Ia's found in the Asiago catalog is used to study how the sensitivity of the method used by RPK will improve with increasing sample size. We conclude that the local group motion should be able to be determined with a sample of ∼100\sim 100 SN Ia light curve shapes.Comment: 13 pages, 2 figures included in a self-unpacking uudecoded gzipped postscript file. We changed some of the power spectra analyzed and expanded the discussion. The postscript file is available at http://pupgga.princeton.edu/disk20/anonymous/feldman/bflows.p

    Date and Rate of Corn Planting

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    Corn is South Dakota’s most important grain crop. It is grown on 4 million acres annually. South Dakota ranks ninth among the states as a corn producer, having one-twentieth of the national acreage and one-thirtieth of the production. The state may be divided into three areas on the basis of the place of corn on the farm: the eastern area, where corn is complementary to wheat and grazing; and the western area, where corn is supplementary grazing

    Optimal Moments for the Analysis of Peculiar Velocity Surveys

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    We present a new method for the analysis of peculiar velocity surveys which removes contributions to velocities from small scale, nonlinear velocity modes while retaining information about large scale motions. Our method utilizes Karhunen--Lo\`eve methods of data compression to construct a set of moments out of the velocities which are minimally sensitive to small scale power. The set of moments are then used in a likelihood analysis. We develop criteria for the selection of moments, as well as a statistic to quantify the overall sensitivity of a set of moments to small scale power. Although we discuss our method in the context of peculiar velocity surveys, it may also prove useful in other situations where data filtering is required.Comment: 25 Pages, 3 figures. Submitted to Ap

    A New Approach to Probing Large Scale Power with Peculiar Velocities

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    We propose a new strategy to probe the power spectrum on large scales using galaxy peculiar velocities. We explore the properties of surveys that cover only two small fields in opposing directions on the sky. Surveys of this type have several advantages over those that attempt to cover the entire sky; in particular, by concentrating galaxies in narrow cones these surveys are able to achieve the density needed to measure several moments of the velocity field with only a modest number of objects, even for surveys designed to probe scales \gtwid 100\hmpc. We construct mock surveys with this geometry and analyze them in terms of the three moments to which they are most sensitive. We calculate window functions for these moments and construct a χ2\chi^2 statistic which can be used to put constraints on the power spectrum. In order to explore the sensitivity of these surveys, we calculate the expectation values of the moments and their associated measurement noise as a function of the survey parameters such as density and depth and for several popular models of structure formation. In addition, we have studied how well these kind of surveys can distinguish between different power spectra and found that, for the same number of objects, cone surveys are as good or better than full-sky surveys in distinguishing between popular cosmological models. We find that a survey with 200−300200-300 galaxy peculiar velocities with distance errors of 15% in two cones with opening angle of ∼10∘\sim 10^\circ could put significant constraints on the power spectrum on scales of 100−300100-300\hmpc, where few other constraints exist.Comment: 15 pages, 3 figures, Some revisions and different figure. Accepted for publication at ApJ letter

    AMERICA'S CUP GRINDERS' POWER OUTPUT CAN BE IMPROVED WITH A BIOMECHANICAL TECHNIQUE INTERVENTION

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    Grinding provides the power behind tacking and gybing, where the yacht crosses the wind to change direction. This study evaluated the effect of a technique intervention on grinding performance. Ten America's Cup grinders were assessed, via videoed joint kinematics and grinder ergometer power output, before and after a technique intervention based on biomechanical principles. Anthropometric measures were obtained from each grinder using ISAK protocols. Maximal strength was assessed using 1 RM bench pull. The intervention produced a 4.7% increase in mean power output (p = 0.012). Regression analysis indicated predictors for grinding performance were COM. position and maximal strength

    Grasses and Legumes for South Dakota

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    Farm operators in South Dakota are seeding considerable acreages of previously cropped land back to grasses and legumes. In recent years the state agricultural experiment stations and the United States Department of Agriculture have introduced or developed species of grasses and legumes which are superior to our native types for seed, hay and grazing purposes. A few outstanding contributions in this field of research have been the work with crested wheatgrass, Ree wheatgrass, and Ladak, Cossack and Ranger alfalfa. Grasses and legumes rank far ahead of any other crop in importance in this state. At present, more than 28,400,000 acres (Fig. 1), twice the acreage of all other crops combined, are in grasses and legumes which furnish a major portion of feed for our grazing animals. An increase in the acreage of grasses and legumes has been adopted as a national policy because forage crops not only aid in conserving the soil but contribute to a better balanced agriculture
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