311 research outputs found
The Relationship Between Soil Test and Small Grain Response to P Fertilization in South Dakota Field Experiments
Phosphorus is one of the two most limiting nutrients to crop production in South Dakota. Because of this fact, many recommendations for P fertilizer are made each day by the South Dakota State University Soil Test Lab. Nearly 65,000 tons of available O are marketed each year in South Dakota as commercial fertilizer. This amounts to over 18 million dollars or expense for South Dakota farmers. Therefore, it becomes essential that recommendations for phosphorus fertilizer be as accurate as our knowledge of the soil-plant system allows. Those recommendations are currently based on the results of the Modified Bray 1, 1:7 soil test, a test used by many states throughout the Midwest. Based on data collected from 74 small grain field experiments over a 13-year period, this test explains less than 30% of the variation in yield response to P fertilization. The purpose of this study was twofold: 1. to compare several alternative soil test on the basis of field response data; and 2. To evaluate the influence of several factors on the relationship between soil test and yield response to P fertilization
Comparison of 2 Alternative Systems for Measuring Vertical Jump Height
https://scholar.dsu.edu/research-symposium/1003/thumbnail.jp
Fertilizer Recommendations Guide
This publication provides information on fertilizer recommendations for crops grown in South Dakota. It also includes information on soil micronutrients
Fertilizing Wheat
This publication provides recommendations for nitrogen, phosphorus, potassium, secondary, and micronutrient requirements of South Dakota soils. Information on fertilizer application and guidance for fertilizing reduced and no-till wheat is also included
Sunyaev-Zeldovich Cluster Counts as a Probe of Intra-Supercluster Gas
X-ray background surveys indicate the likely presence of diffuse warm gas in
the Local Super Cluster (LSC), in accord with expectations from hydrodynamical
simulations. We assess several other manifestations of warm LSC gas; these
include anisotropy in the spatial pattern of cluster Sunyaev-Zeldovich (S-Z)
counts, its impact on the CMB temperature power spectrum at the lowest
multipoles, and implications on measurements of the S-Z effect in and around
the Virgo cluster.Comment: 14 pages, 6 figures, draft versio
A tentative derivation of the main cosmological parameters
Based on the assumption that some apparent properties of the observable
universe are accurate at a reasonable level of approximation, a tentative is
made to independently derive the values of the baryon density parameter, the
Hubble constant, the cosmic microwave background temperature and the helium
mass fraction. The obtained values are in excellent agreement with those given
by the most recent observational data.Comment: 13 pages. Accepted for publication in Astrophysics & Space Scienc
A quantum mechanical relation connecting time, temperature, and cosmological constant of the universe: Gamow's relation revisited as a special case
Considering our expanding universe as made up of gravitationally interacting
particles which describe particles of luminous matter and dark matter and dark
energy which is described by a repulsive harmonic potential among the points in
the flat 3-space, we derive a quantum mechanical relation connecting,
temperature of the cosmic microwave background radiation, age, and cosmological
constant of the universe. When the cosmological constant is zero, we get back
the Gamow's relation with a much better coefficient. Otherwise, our theory
predicts a value of the cosmological constant
when the present values of cosmic microwave background temperature of 2.728 K
and age of the universe 14 billion years are taken as input.Comment: 4 pages, 1 figure, Study of the Universe from a condensed matter
point of view, section III corrected with a single body potentia
Determination of the cosmic far-infrared background level with the ISOPHOT instrument
The cosmic infrared background (CIRB) consists mainly of the integrated light
of distant galaxies. In the far-infrared the current estimates of its surface
brightness are based on the measurements of the COBE satellite. Independent
confirmation of these results is still needed from other instruments. In this
paper we derive estimates of the far-infrared CIRB using measurements made with
the ISOPHOT instrument aboard the ISO satellite. The results are used to seek
further confirmation of the CIRB levels that have been derived by various
groups using the COBE data. We study three regions of very low cirrus emission.
The surface brightness observed with the ISOPHOT instrument at 90, 150, and 180
um is correlated with hydrogen 21 cm line data from the Effelsberg radio
telescope. Extrapolation to zero hydrogen column density gives an estimate for
the sum of extragalactic signal plus zodiacal light. The zodiacal light is
subtracted using ISOPHOT data at shorter wavelengths. Thus, the resulting
estimate of the far-infrared CIRB is based on ISO measurements alone. In the
range 150 to 180 um, we obtain a CIRB value of 1.08+-0.32+-0.30 MJy/sr quoting
statistical and systematic errors separately. In the 90 um band, we obtain a
2-sigma upper limit of 2.3 MJy/sr. The estimates derived from ISOPHOT
far-infrared maps are consistent with the earlier COBE results.Comment: Accepted for publication in A&A, 17 page
Genetic Reporter System for Positioning of Proteins at the Bacterial Pole
Spatial organization within bacteria is fundamental to many cellular processes, although the basic mechanisms underlying localization of proteins to specific sites within bacteria are poorly understood. The study of protein positioning has been limited by a paucity of methods that allow rapid large-scale screening for mutants in which protein positioning is altered. We developed a genetic reporter system for protein localization to the pole within the bacterial cytoplasm that allows saturation screening for mutants in Escherichia coli in which protein localization is altered. Utilizing this system, we identify proteins required for proper positioning of the Shigella autotransporter IcsA. Autotransporters, widely distributed bacterial virulence proteins, are secreted at the bacterial pole. We show that the conserved cell division protein FtsQ is required for localization of IcsA and other autotransporters to the pole. We demonstrate further that this system can be applied to the study of proteins other than autotransporters that display polar positioning within bacterial cells.Molecular and Cellular Biolog
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