2,691 research outputs found

    Assessment of the NASA Flight Assurance Review Program

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    The NASA flight assurance review program to develop minimum standard guidelines for flight assurance reviews was assessed. Documents from NASA centers and NASA headquarters to determine current design review practices and procedures were evaluated. Six reviews were identified for the recommended minimum. The practices and procedures used at the different centers to incorporate the most effective ones into the minimum standard review guidelines were analyzed and guidelines for procedures, personnel and responsibilies, review items/data checklist, and feedback and closeout were defined. The six recommended reviews and the minimum standards guidelines developed for flight assurance reviews are presented. Observations and conclusions for further improving the NASA review and quality assurance process are outlined

    Current Status of the Northern Saw-whet Owl (Aegolius acadicus) in Arkansas

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    The secretive Northern Saw-whet Owl (Aegolius acadicus) is believed to be much more widespread during fall and winter than previously thought. Of the few places in the southern United States conducting research on this species, all have been successful at capturing birds. A total of 12 historic records existed for Arkansas until our work began in fall of 2014. The first confirmed record was in 1959 and the most recent, prior to this research, was in 2010. Over the course of two field seasons, we captured and banded 24 Northern Saw-whet Owls in rural Madison County. All birds were mist-netted along a trail, in woodland composed of pine and cedar with fairly dense undergrowth. Two were captured during our 2014 season after a late start and 22 were captured in 2015, likely the result of an earlier start. Comparing our data to that of several other banding operations in the south, it would appear that the peak of migration in Arkansas is late October through early November, with capture rates dropping by early December. Of the birds captured, all but one was female, the most common sex this far south. A variety of age classes were identified, with a fairly even distribution of hatch-year, second-year, and after-second-year birds. Exactly from where the saw-whets are migrating is unknown, although several foreign recoveries in Missouri and four recoveries in Arkansas suggest they are coming from the western Great Lakes region. Once considered a vagrant, based on this research, the saw-whet appears to be a fall migrant to the state of Arkansas

    Social Conflict: Some Basic Principles

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    The term conflict has two generally accepted meanings.\u27 The first refers to overt conflict-an argument, fight, or struggle. The second refers to subjective conflict-Party\u27s perception that Party and Other have opposing beliefs or interests, or that Other has deprived or annoyed Party in some way. The latter concept is richer for theory building than the former, in that there are several strategies Party can employ in reaction to subjective conflict. Party can take a contentious approach and retaliate, or Party can try to impose its will on Other by means of an argument, demand, or threat. This strategy is very likely to lead to overt conflict. Instead of contending, Party can remain inactive or yield to Other, or Party can engage in problem solving, with the aim of finding a solution to the conflict that both of them can accept. One sometimes finds combinations of these strategie

    History and Fall Migration of Northern Saw-Whet Owls (Aegolius acadicus) in Arkansas

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    The secretive Northern Saw-whet Owl (Aegolius acadicus) is believed to be much more widespread during fall and winter than previously thought in the southern United States. To see if they occur more frequently in Arkansas, we initiated a banding study in fall of 2014 in northwestern Arkansas. Prior to that, only 12 historic records existed for Arkansas between 1959 and 2010. Over the course of two field seasons, we captured and banded 24 Northern Saw-whet Owls in rural Madison County. All birds were mist-netted along a trail, in woodland composed of pine and cedar with fairly dense undergrowth. Two were captured during our 2014 season when we started in late November and 22 were captured between late October and early December in 2015. We also had at least 10 birds vocalizing at our site. It would appear that the peak of migration in Arkansas is late October through early November, with capture rates dropping off by early December. All but one of the captured birds were females, the most common sex this far south. There was a fairly even distribution of hatch-year, second year, and after-second-year birds and hatch-year birds and adults arrived at about the same time in late October and early November in 2015. Exactly where the owls are migrating from is unknown, although three foreign recoveries in Missouri and four recoveries in Arkansas suggest they are coming from the western Great Lakes region. Once considered a vagrant, based on our research, the Northern Saw-whet Owl appears to be an uncommon fall migrant, at least in the northwestern part of Arkansas. Comparing our data with that for central Missouri, about the same number of birds were captured at the same rates for about the same length of time, suggesting that Northern Saw-whet Owls are probably more common in the Ozarks than previously thought

    SOME CHARACTERISTICS OF CHOICE BEHAVIOR IN RISKY SITUATIONS *

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73591/1/j.1749-6632.1961.tb20178.x.pd

    Geometry Optimizations of Open-Shell Systems with the Fragment Molecular Orbital Method

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    The ability to perform geometry optimizations on large molecular systems is desirable for both closed- and open-shell species. In this work, the restricted open-shell Hartree–Fock (ROHF) gradients for the fragment molecular orbital (FMO) method are presented. The accuracy of the gradients is tested, and the ability of the method to reproduce adiabatic excitation energies is also investigated. Timing comparisons between the FMO method and full ab initio calculations are also performed, demonstrating the efficiency of the FMO method in modeling large open-shell systems

    tt-Martin boundary of killed random walks in the quadrant

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    We compute the tt-Martin boundary of two-dimensional small steps random walks killed at the boundary of the quarter plane. We further provide explicit expressions for the (generating functions of the) discrete tt-harmonic functions. Our approach is uniform in tt, and shows that there are three regimes for the Martin boundary.Comment: 18 pages, 2 figures, to appear in S\'eminaire de Probabilit\'e

    NCBI Reference Sequences (RefSeq): current status, new features and genome annotation policy

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    The National Center for Biotechnology Information (NCBI) Reference Sequence (RefSeq) database is a collection of genomic, transcript and protein sequence records. These records are selected and curated from public sequence archives and represent a significant reduction in redundancy compared to the volume of data archived by the International Nucleotide Sequence Database Collaboration. The database includes over 16 000 organisms, 2.4 × 106 genomic records, 13 × 106 proteins and 2 × 106 RNA records spanning prokaryotes, eukaryotes and viruses (RefSeq release 49, September 2011). The RefSeq database is maintained by a combined approach of automated analyses, collaboration and manual curation to generate an up-to-date representation of the sequence, its features, names and cross-links to related sources of information. We report here on recent growth, the status of curating the human RefSeq data set, more extensive feature annotation and current policy for eukaryotic genome annotation via the NCBI annotation pipeline. More information about the resource is available online (see http://www.ncbi.nlm.nih.gov/RefSeq/)

    Effect of route of administration of lasalocid on response of young dairy calves

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    Forty newborn bull calves were assigned to one of four feeding groups. The feeds either contained lasalocid in milk (M), prestarter (PS), and starter (S); lasalocid in PS and S; lasalocid in S only; or no lasalocid. Calves were fed M at 8% of birth weight (bw) daily and offered PS to a maximum of 0.5 lb daily. When 0.5 lb of PS was consumed in one day the calves were fed M at 4% of bw daily. They were weaned when they consumed dry feed at the rate of 1.3% of bw. Daily feed intake and weekly weight gains of calves were evaluated. Blood serum samples were used to evaluate blood metabolites at wk 4, 8, and 12. We concluded that lasalocid in M, PS, and S supported greater feed efficiency and allowed earlier weaning with less animal variation than when lasalocid was delivered in PS and S, only in S, or not at all
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