683 research outputs found

    Effects of six cycles of reciprocal full-sib selection on several grain, stalk, and root traits in BS11

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    Evaluation of 120 unselected S(,1) lines from each of the BS11CO and BS11(FR)C6 maize (Zea mays L.) populations was conducted to investigate changes in means, genotypic variances and phenotypic correlations that have occurred after six cycles of reciprocal full-sib selection. Mechanically harvestable grain yield, grain moisture, stalk lodging, root lodging and dropped ears were measured at Kanawha and Martinsburg in 1981 and 1982. Twenty-nine agronomic traits were measured at Ames in 1981 and 1982. Variance components, heritabilities, means, and phenotypic and genotypic correlations among traits were estimated for combined analyses;Significant decreases in genetic variability, associated with reciprocal full-sib selection, were detected for 13 traits. Eleven traits were significantly changed through selection. The changes in means and variances of traits were attributed to both selection and inbreeding. Changes in genotype x environment interaction variances and their effects on heritability were discussed. Changes in phenotypic correlations between traits and their impact on continued selection were discussed;Artificial inoculation of stalk rot organisms failed to cause significant reductions in grain yield components although it significantly increased stalk lodging. Incorporation of artificial inoculation of stalk rot organisms and subsequent rind puncture and stalk lodging evaluation of S(,1) families in breeding programs were recommended for BS11 because of the favorable associations between these measures of stalk quality and reduced stalk lodging. Root pulling of S(,1) families was also recommended because of normal distribution of the data, lack of consistent expression in root lodging, and favorable associations between root pull scores and reduced root lodging and improved stalks

    Simulation and Interpretation of the Genesis of Tropical Storm Gert (2005) as Part of the NASA Tropical Cloud Systems and Processes Experiment

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    Several hypotheses have been put forward for the how tropical cyclones (tropical storms and hurricanes in the Atlantic) first develop circulation at the surface, a key event that needs to occur before a storm can begin to draw energy from the warm ocean. One hypothesis suggests that the surface circulation forms from a "top-down" approach in which a storm s rotating circulation begins at middle levels of the atmosphere and builds down to the surface through processes related to light "stratiform" (horizontally extensive) precipitation. Another hypothesis suggests a bottom-up approach in which deep thunderstorm towers (convection) play the major role in spinning up the flow at the surface. These "hot towers" form in the area of the mid-level circulation and strongly concentrate this rotation at low levels within their updrafts. Merger of several of these hot towers then intensifies the surface circulation to the point in which a storm forms. This paper examines computer simulations of Tropical Storm Gert (2005), which formed in the Gulf of Mexico during the National Aeronautics and Space Administration s (NASA) Tropical Cloud Systems and Processes (TCSP) Experiment, to investigate the development of low-level circulation and, in particular, whether stratiform or hot tower processes were responsible for the storm s formation. Data from NASA satellites and from aircraft were used to show that the model did a good job of reproducing the formation and evolution of Gert. The simulation shows that a mix of both stratiform and convective rainfall occurred within Gert. While the stratiform rainfall clearly acted to increase rotation at middle levels, the diverging outflow beneath the stratiform rain worked against spinning up the low-level winds. The hot towers appeared to dominate the low-level flow, producing intense rotation within their cores and often being associated with significant pressure falls at the surface. Over time, many of these hot towers merged, with each merger adding to the rotation of the storm and the pressure falls at the surface. This process continued to increase the strength of the storm until the storm made landfall on the east coast of Mexico. These results support the bottom-up hypothesis for development

    Understanding OA Ebook Usage: Toward a Common Framework

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    Redacted version of narrative for a proposal to the Andrew W. Mellon Foundation to support the development of international standards and practices for measuring and reporting usage of open-access ebooksSubmitted to the Andrew W. Mellon Foundation on April 27, 2018https://deepblue.lib.umich.edu/bitstream/2027.42/143840/1/Redacted Grant Narrative - OA Ebook Usage_FINAL SUBMISSION_042718.pdfDescription of Redacted Grant Narrative - OA Ebook Usage_FINAL SUBMISSION_042718.pdf : Grant Narrativ

    Coalition Battle Management Language (C-BML) Study Group Final Report

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    Interoperability across Modeling and Simulation (M&S) and Command and Control (C2) systems continues to be a significant problem for today\u27s warfighters. M&S is well-established in military training, but it can be a valuable asset for planning and mission rehearsal if M&S and C2 systems were able to exchange information, plans, and orders more effectively. To better support the warfighter with M&S based capabilities, an open standards-based framework is needed that establishes operational and technical coherence between C2 and M&S systems

    Avionics Architectures for Exploration: Building a Better Approach for (Human) Spaceflight Avionics

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    The field of Avionics is advancing far more rapidly in terrestrial applications than in space flight applications. Spaceflight Avionics are not keeping pace with expectations set by terrestrial experience, nor are they keeping pace with the need for increasingly complex automation and crew interfaces as we move beyond Low Earth Orbit. NASA must take advantage of the strides being made by both space-related and terrestrial industries to drive our development and sustaining costs down. This paper describes ongoing efforts by the Avionics Architectures for Exploration (AAE) project chartered by NASA's Advanced Exploration Systems (AES) Program to evaluate new avionic architectures and technologies, provide objective comparisons of them, and mature selected technologies for flight and for use by other AES projects. Results from the AAE project's FY13 efforts are discussed, along with the status of FY14 efforts and future plans

    A Data Trust for Industry Data Sharing

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    This document is an extract from the report Building a Trusted Framework for Coordinating OA Monograph Usage Data, which forms part of the Andrew W. Mellon Foundation funded project, Understanding OA Ebook Usage: Toward a Common Framework

    Seed Quality Assurance in Maize Breeding Programs: Tests to Explain Variations in Maize Inbreds and Populations

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    Maize (Zea mays L.) breeders are interested in evaluating the seed quality of their inbred lines, as seed quality has a strong relationship to field emergence. There is little information, however, on the influence of the seed quality of the inbred on field emergence of the hybrid. The objectives of this research were to (i) determine whether seed quality tests and a seed quality index of the inbred parents and F2 seed are correlated with field emergence of F1hybrids, and (ii) determine how many tests are necessary to calculate this index. Standard germination (SG), saturated cold (SC), and soak (Soak) tests, and the inbred quality index (IQI) were calculated on inbred parents and their corresponding F2 progeny, and field emergence was measured on associated F1 hybrids produced in Clinton, IL in 2002 and 2003. The tests and index of the parental inbreds and F2 progeny correlated poorly with early field emergence of the F1 hybrids. All tests were required to calculate the seed quality index. By averaging several seed quality tests into a single index, the poor seed quality performance of inbreds and F2 populations in some tests can be masked by other tests. The seed quality index might be useful when ranking inbreds based on seed quality but not as a selection tool

    Avionics Architectures for Exploration: Ongoing Efforts in Human Spaceflight

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    The field of Avionics is advancing far more rapidly in terrestrial applications than in spaceflight applications. Spaceflight Avionics are not keeping pace with expectations set by terrestrial experience, nor are they keeping pace with the need for increasingly complex automation and crew interfaces as we move beyond Low Earth Orbit. NASA must take advantage of the strides being made by both space-related and terrestrial industries to drive our development and sustaining costs down. This paper describes ongoing efforts by the Avionics Architectures for Exploration (AAE) project chartered by NASA's Advanced Exploration Systems (AES) Program to evaluate new avionic architectures and technologies, provide objective comparisons of them, and mature selected technologies for flight and for use by other AES projects. The AAE project team includes members from most NASA centers, and from industry. It is our intent to develop a common core avionic system that has standard capabilities and interfaces, and contains the basic elements and functionality needed for any spacecraft. This common core will be scalable and tailored to specific missions. It will incorporate hardware and software from multiple vendors, and be upgradeable in order to infuse incremental capabilities and new technologies. It will maximize the use of reconfigurable open source software (e.g., Goddard Space Flight Center's (GSFC's) Core Flight Software (CFS)). Our long-term focus is on improving functionality, reliability, and autonomy, while reducing size, weight, and power. Where possible, we will leverage terrestrial commercial capabilities to drive down development and sustaining costs. We will select promising technologies for evaluation, compare them in an objective manner, and mature them to be available for future programs. The remainder of this paper describes our approach, technical areas of emphasis, integrated test experience and results as of mid-2014, and future plans. As a part of the AES Program, we are encouraged to set aggressive goals and fall short if necessary, rather than to set our sights too low. We are also asked to emphasize providing our personnel with hands-on experience in development, integration, and testing. That we have embraced both of these philosophies will be evident in the descriptions below
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