4,684 research outputs found

    The Gorenstein Colength of an Artinian Local Ring

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    In this paper, we make the notion of approximating an Artinian local ring by a Gorenstein Artin local ring precise using the concept of Gorenstein colength. We also answer the question as to when the Gorenstein colength is at most two.Comment: The title and layout have changed, has been shortened to 9 pages. Published in Journal of Algebr

    Concepts in Crop Rotations

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    Effects of boron foliar fertilization on irrigated soybean (Glycine max L. Merr.) in the Mississippi River Valley Delta of themidsouth, USA

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    Boron (B) deficiencies have been observed in some irrigated soybean fields in the lower Mississippi River Valley on silt loam soils of pH >7.0 and irrigated with water having high calcium (Ca) and magnesium (Mg). Boron fertilization effects on irrigated soybean grown using the Early Soybean Production System (ESPS) in the Midsouth have yet to be determined. Three commercial cultivars available for use in the ESPS were selected and foliar fertilized with a B solution at GS’s R3 and/or R5 at concentrations of 280 g B ha-1, 560 g B ha-1, or a split application at both R3 and R5 of 280 g B ha-1. Established stands were greater in 2016 than 2015 (262,378 vs. 180,804 plants ha-1) resulting in respective mean yields of 4239.7 vs. 3794.7 kg ha-1, but no significant interactions with years were noted.  Yields of AG4632 were unaffected by B fertilization.  Boron fertilization of P47T36 at R5 generally improved yields (>4000.0 kg ha-1) over the control (3668.6 kg ha-1) and applications at R3 (<3900.0 kg ha-1). The 560 g B ha-1 treatment at R3 for P50T64 produced less seed (3742.5 kg ha-1) than all other treatments while no other differences were noted. Some differences were noted in 100 seed weights but they were neither large nor consistent. It is doubtful that economic benefits to soybean in the Mississippi Delta would result unless a B deficiency was positively identified early in a growing season or in previous seasons.  It is concluded from this experiment, that foliar fertilization of soybean with B, as a general production practice, is not recommended

    Irrigated Soybean Leaf Photosynthesis in the Humid Subtropical Midsouth

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    Photosynthesis (CER (μmol CO2mleaf area-2 s−1)), stomatal conductance (gsw), and intercellular [CO2] (Ci) of soybean (Glycine max L. Merr.) grown using the early soybean production system (ESPS) of the midsouth were determined. Three irrigated cultivars were grown using ESPS on Bosket (Mollic Hapludalfs) and Dundee (Typic Endoaqualf) soils in 2011 and 2012 at Stoneville, MS. Single leaf CER, gsw, and Ci were determined at growth stages R3, R4, and R5 using decreasing photosynthetic photon flux densities (PPFD, μmol m−2 s−1) beginning at 2000 PPFD and decreasing by 250 PPFD increments to 250 PPFD. Photosynthesis changes fit a quadratic polynomial for all fixed variables and range from ~6.0 and 9.0 CER at 250 PPFD and ~22.0 to 28.0 CER at 2000 PPFD. No cultivar differences in CER, gsw, or Ci were noted at any growth stage or site either year. In 2012, CER, gsw, and Ci were lower when measured at R5 than the two previous growth stages, which was not observed in 2011. The R5 sampling in 2012 had accumulated 39 to 70 more growing degree units at 10°C base temperature (GDU 10’s) than in 2011 and were likely more mature. Increased soybean yields from ESPS appear not to result from higher leaf CER

    Grain sorghum (Sorghum bicolor L. Moench) fails to consistently respond to N-fertilizer when grown on a Tunica clay soil in the lower Mississippi River Valley, USA

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    Information on producing grain sorghum (Sorghum bicolor L. Moench) on clay soils found in the Mississippi Delta and similar regions is comparatively limited to what is known for the crop in other environments, especially regarding nitrogen fertility. A study conducted in 2014 and 2015 on a Tunica clay soil (clayey over loamy, montmorillonitic, non-acid, thermic, Vertic Halaquept) examined the effects of three N-fertilizer rates (0.0, 112.0, and 224.0 kg N ha-1) on yield and yield components of six commercially available hybrids. The 2014 seeding did not require irrigation while three irrigations were applied in 2015. No yield differences in hybrids or N-fertility treatments were observed in 2014 likely due to waterlogged soil, resulting in denitrification, but added N did increase yields in 2015. No consistent differences in yield or yield components occurred between hybrids either year. Yields in 2014 and at 0.0 or 112.0 kg ha-1 added N-fertilizer in 2015 were sub-standard to regional variety trial data. Rates of N-fertilizer of at least 224.0 kg N ha-1 appear necessary for grain sorghum grown on clay soils in the humid sub-tropics

    Post-training load-related changes of auditory working memory: An EEG study

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    Working memory (WM) refers to the temporary retention and manipulation of information, and its capacity is highly susceptible to training. Yet, the neural mechanisms that allow for increased performance under demanding conditions are not fully understood. We expected that post-training efficiency in WM performance modulates neural processing during high load tasks. We tested this hypothesis, using electroencephalography (EEG) (N = 39), by comparing source space spectral power of healthy adults performing low and high load auditory WM tasks. Prior to the assessment, participants either underwent a modality-specific auditory WM training, or a modality-irrelevant tactile WM training, or were not trained (active control). After a modality-specific training participants showed higher behavioral performance, compared to the control. EEG data analysis revealed general effects of WM load, across all training groups, in the theta-, alpha-, and beta-frequency bands. With increased load theta-band power increased over frontal, and decreased over parietal areas. Centro-parietal alpha-band power and central beta-band power decreased with load. Interestingly, in the high load condition a tendency toward reduced beta-band power in the right medial temporal lobe was observed in the modality-specific WM training group compared to the modality-irrelevant and active control groups. Our finding that WM processing during the high load condition changed after modality-specific WM training, showing reduced beta-band activity in voice-selective regions, possibly indicates a more efficient maintenance of task-relevant stimuli. The general load effects suggest that WM performance at high load demands involves complementary mechanisms, combining a strengthening of task-relevant and a suppression of task-irrelevant processing

    LIMS: Livestock Information Management System - Introductory guide

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    This introductory guide has been written to facilitate the use of the LIMS (Livestock Information Management System) package, details of which are given in the system documentation manual. The LIMS system was based on the experience gained from IDEAS (ILCA's Data Entry and Analysis System) a software package designed for the management of animal performance data. This guide takes the reader through the entire features of the LIMS software using sample data sets. The user is most likely to gain if the manual is read while performing the suggested tasks

    Sorting Cattle - A Review

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    The purpose of this report is to review the most current concepts of sorting cattle. The reader should be aware that individual feedlot programs and markets will dictate the involvement and extent of sorting and its usefulness

    Feeding Value of Rolled and Whole Shelled Waxy Corn in Finishing Diets

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    Waxy corn in rolled or whole shelled form was compared with rolled normal corn in finishing diets for cattle. Steers (n = 144; initial BW = 765 lb) were allocated to 18 pens and fed these three grain types in a 123 d experiment. The waxy corn was a sole source grain that tested \u3e99% pure waxy endosperm. The normal rolled was acquired as needed through a commercial elevator. Diets contained 78% grain as NR) normal rolled; WR) waxy rolled; or WW) waxy whole grain. Diet had no effect on DMI and there were no differences for production variables between NR and WR treatments (P \u3e 0.10). When waxy corn was fed in whole grain form there was a 7% reduction (P \u3c 0.05) in ADG and a 5% increase (P \u3c 0.05) in feed required per pound of gain. The reduced ADG caused by WW corresponded to lower carcass weight. The WR treatment caused an increase in KPH (P \u3c 0.05). No other effects on carcass characteristics were observed. In rolled form waxy and normal corn have comparable feeding value in finishing diets. Rolling waxy corn will increase feed value by approximately 5%

    Nutrient Uptake of Maize Affected by Nitrogen and Potassium Fertility in a Humid Subtropical Environment

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    Nitrogen (N) and potassium (K) fertility management of maize (Zea mays L.) in the humid subtropical Mississippi Delta may differ from a temperate climate because of its use in rotation with cotton (Gossypium hirsutum L.), soil temperatures rarely falling to 0 °C, and heavy winter rains that facilitate nutrient losses. An experiment to determine the [N] (concentration = [ ]), phosphorus [P], [K], calcium [Ca], magnesium [Mg], iron [Fe], manganese [Mn], zinc [Zn], and copper [Cu] and their total contents plant-1 of maize grown in rotation with cotton, using N fertility levels of (134, 179, 224, 269, and 314 kg N ha-1) in combination with K fertility levels of (0, 45, 90, and 134 kg K ha-1) was conducted in 2000 and 2001 at Tribbett, MS. Ear leaves, immature ears, and husks collected at growth stage R2 and grain and stover collected 21 days after R6 were dried, weighed, and analyzed for nutrient concentration. Plots were also harvested for yield, kernel weight, grain bulk density, and harvest index (HI). Increased [N] values of about 1.3 mg g-1 occurred in all organs except the stover between 134 and 314 kg N ha-1 N fertility. Stover [N] increased approximately 3.0 mg g-1 within the same N fertility range. Total N content of ear leaves, grain, and stover increased by about 11.0, 550.0, and 730.0 mg plant-1, respectively, with N fertility increased from 134 to 314 kg N ha-1. Yields, kernel weights, grain bulk densities, and harvest indices also increased with added N fertility. Several micronutrient concentrations and contents increased as N fertility increased
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