732 research outputs found

    Considerations in No-Till Small Grain Production

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    Small grains have become an important component of many crop rotations in Kentucky. Seedbed preparation has typically involved various degrees of tillage in which much of the residue from the previous crop is buried. Under such conditions, a field may be vulnerable to severe soil loss during periods of heavy rainfall until the plants have produced enough vegetative growth to cover the soil surface. Eliminating tillage in small grain production would not only reduce soil loss but also reduce labor cost and increase the timeliness of planting. Interest in no-till small grain production is growing. One survey reports that in 1983 approximately 50,000 acres of small grains were planted using no-tillage in Kentucky. Research information on winter survival, seed placement, residue management, and nitrogen fertilization is now becoming available

    Response of Soybeans to Available Potassium in Three Kentucky Soils

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    Soybeans are produced in nearly all of Kentucky\u27s soil physiographic regions. Soybean response to potassium (K) fertilization and soil test Kvaries with soil type and location. This variation may be associated with the wide range in soil chemical and mineralogical properties among the different regions. Of particular interest are differences in that level of soil test Kat which no further yield response to K fertilizer application would be expected. The main objective of this work was to evaluate the soil K-soybean response relationship on three different field sites where soybean yields were increased by fertilizer K. Several measures of soil K availability were related to soybean yield

    Fragipan Horizon Fragmentation in Slaking Experiments with Amendment Materials and Ryegrass Root Tissue Extracts

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    Slaking experiments were conducted of fragipan clods immersed in solutions of poultry manure, aerobically digested biosolid waste (ADB), fluidized bed combustion byproduct (FBC), D-H2O, CaCO3, NaF, Na-hexa-metaphosphate, and ryegrass root biomass. The fragipan clods were sampled from the Btx horizon of an Oxyaquic Fragiudalf in Kentucky. Wet sieving aggregate analysis showed significantly better fragmentation in the NaF, Na-hexa-metaphosphate, and ryegrass root solutions with a mean weight diameter range of 15.5-18.8 mm compared to the 44.2-47.9 mm of the poultry manure, ADB, and FBC treatments. Dissolved Si, Al, Fe, and Mn levels released in solution were ambiguous. The poor efficiency of the poultry manure, ADB, and FBC treatments was attributed to their high ionic strength, while the high efficiency of the NaF, Na-hexa-metaphosphate, and rye grass root solutions to their high sodium soluble ratio (SSR). A slaking mechanism is proposed suggesting that aqueous solutions with high SSR penetrate faster into the fragipan capillaries and generate the critical swelling pressure and shearing stress required to rupture the fragipan into several fragments. Additional fragmentation occurs in a followup stage during which potential Si, Al, Fe, and Mn binding agents may be released into solution. Field experiments testing these findings are in progress

    Moving Toward, Moving Against, and Moving Away: An Interpersonal Approach to Construct Validation of the Horney–Coolidge Type Inventory

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    Karen Horney’s interpersonal theory of adjustment defined three different neurotic trends involving characteristic social behavior and motives: compliant (moving toward people), aggressive (moving against people), and detached (moving away from people). The Horney–Coolidge Type Inventory (HCTI) was developed to assess these trends, but has not been validated using standard methods in the interpersonal perspective. The studies reported here refined the structure of the HCTI, and utilized the structural summary method (SSM) to identify relationships of the three shortened HCTI trend scales with the interpersonal circumplex (IPC) in single university (n = 514) and multisite university (n = 3,283) samples. Results across both studies confirmed predicted interpersonal characteristics of each trend: Compliance was associated with warm submissiveness, aggression was associated with hostile dominance, and detachment was associated with hostile or cold submissiveness. However, analyses of facets within the three HCTI trend domains revealed significant differences. Results are discussed as a potential guide to further refinement of assessments of the Horney maladaptive trends, and support inclusion of Horney’s model in current interpersonal theory

    Quantum Electronics

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    Contains reports on three research projects.U. S. Air Force Office of Scientific Research (Contract F44620-71-C-0051)Joint Services Electronics Program (Contract DAAB07-71-C-0300)University of California, Livermore (Subcontract No. 7877409)U. S. Army Research Office - Durham (Contract DAHC04-72-C-0044

    Cognitive effects of one season of head impacts in a cohort of collegiate contact sport athletes

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    Objective: To determine whether exposure to repetitive head impacts over a single season negatively affects cognitive performance in collegiate contact sport athletes. Methods: This is a prospective cohort study at 3 Division I National Collegiate Athletic Association athletic programs. Participants were 214 Division I college varsity football and ice hockey players who wore instrumented helmets that recorded the acceleration-time history of the head following impact, and 45 noncontact sport athletes. All athletes were assessed prior to and shortly after the season with a cognitive screening battery (ImPACT) and a subgroup of athletes also were assessed with 7 measures from a neuropsychological test battery. Results: Few cognitive differences were found between the athlete groups at the preseason or postseason assessments. However, a higher percentage of the contact sport athletes performed more poorly than predicted postseason on a measure of new learning (California Verbal Learning Test) compared to the noncontact athletes (24% vs 3.6%; p \u3c 0.006). On 2 postseason cognitive measures (ImPACT Reaction Time and Trails 4/B), poorer performance was significantly associated with higher scores on several head impact exposure metrics. Conclusion: Repetitive head impacts over the course of a single season may negatively impact learning in some collegiate athletes. Further work is needed to assess whether such effects are short term or persistent

    New Crayfish Species Records from the Sipsey Fork Drainage, Including Lewis Smith Reservoir (Alabama, USA): Native or Introduced Species?

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    As part of a study of aquatic faunal community changes along riverine-lacustrine transition zones upstream of Lewis Smith Reservoir in northwest Alabama, USA, we collected crayfish from 60 sites in the Sipsey Fork, Brushy Creek, and selected tributaries (Black Warrior River system). After finding two unexpected and possibly-introduced crayfish species, we expanded our investigation of crayfish distributions to include crayfish obtained from stomachs of black bass ( Micropterus spp.) caught at seven sites in the reservoir. To explore what crayfish species were in the drainage historically, we examined museum databases as well as stomach and intestinal contents of a variety of preserved fishes that were caught in the Sipsey Fork and Brushy Creek drainages upstream of the reservoir in the early 1990’s. Of the seven crayfish species collected, one, Orconectes ( Procericambarus ) sp. nr ronaldi , was not previously reported from Alabama, and another, O. lancifer , was not reported from the Black Warrior River system prior to the study. Three are known or possibly introduced species. Upstream of the reservoir, the native species Cambarus obstipus, C. striatus , and O. validus were common. The same three species were found in fish collected in the 1990’s. Orconectes perfectus was found only in the reservoir but may be native to the drainage. Orconectes lancifer was in the reservoir and in stream reaches influenced by the reservoir. Evidence points to O. lancifer being introduced in the drainage, but this is uncertain. Orconectes sp. nr ronaldi was found in a relatively small portion of Brushy Creek and its tributaries, in both flowing and impounded habitats, and may be introduced. Orconectes virilis is introduced in Alabama and was found only in stomachs of fish collected in the reservoir

    Quantum Electronics

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    Contains reports on three research projects.U. S. Air Force - Office of Scientific Research (Contract F44620-71-C-0051)Joint Services Electronics Program (Contract DAAB07-74-C-0630)University of California, Livermore (Subcontract 7877409
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