2,123 research outputs found

    \u3ci\u3eAnoplophora Glabripennis\u3c/i\u3e Within-Tree Distribution, Seasonal Development, and Host Suitability in China and Chicago

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    Established populations of the Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), were first reported in the United States in New York in 1996, Illinois in 1998, and New Jersey in 2002. A federal quarantine and an eradication program were implemented in 1997, involving tree surveys and removal of infested trees. We recorded the number of A. glabripennis life stages found at several locations along the main trunk and major branches of naturally infested trees in China (species of Populus, Salix, and Ulmus) and Chicago, Illinois (species of Acer, Fraxinus, and Ulmus) during 1999 to 2002. Typically, A. glabripennis initiated attack near the crown base along both the trunk and main branches. The one exception to this pattern was on Populus trees in China that had branches along the entire trunk, in which case A. glabripennis initiated attack along the lower trunk. Larvae were the dominant overwintering stage in both countries. A host suitability index for A. glabripennis was calculated for each tree with the formula: (number of living life stages + number of exit holes) / number of oviposition pits. The mean host suitability index was higher on Populus and Salix than Ulmus in China, and generally higher on Acer and Ulmus than Fraxinus in Chicago. Eleven genera of trees (N = 1465 trees) were infested by A. glabripennis in Chicago; in decreasing order of tree frequency they included Acer, Ulmus, Fraxinus, Aesculus, Betula, Salix, Celtis, Malus, Pyrus, Sorbus, and Tilia. When the proportion of each genus of infested street trees (N = 958 trees in 7 genera) was compared to its proportion of all Chicago street trees based on a 2003 inventory (N = 539,613 trees in 45 genera), A. glabripennis showed a significant preference to infest the genera Acer and Ulmus. Based on our results, inspectors should focus their efforts on upper trunks and lower branches of Acer and Ulmus trees

    Automated Data for DevSecOps Programs

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    Symposium PresentationApproved for public release; distribution is unlimited

    Automated Data for DevSecOps Programs

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    Excerpt from the Proceedings of the Nineteenth Annual Acquisition Research SymposiumAutomation in DevSecOps (DSO) transforms the practice of building, deploying, and managing software intensive programs. Although this automation supports continuous delivery and rapid builds, the persistent manual collection of information delays (by weeks) the release of program status metrics and the decisions they are intended to inform. Emerging DSO metrics (e.g., deployment rates, lead times) provide insight into how software development is progressing but fall short of replacing program control metrics for assessing progress (e.g., burn rates against spend targets, integration capability tar-get dates, and schedule for the minimum viable capability release). By instrumenting the (potentially in-teracting) DSO pipelines and supporting environments, the continuous measurement of status, identifica-tion of emerging risks, and probabilistic projections are possible and practical. In this paper, we discuss our research on the information modeling, measurement, metrics, and indicators necessary to establish a continuous program control capability that can keep pace with DSO management needs. We discuss the importance of interactive visualization dashboards for addressing program information needs. We also identify and address the gaps and barriers in the current state of the practice. Finally, we recommend future research needs based on our initial findings.Approved for public release; distribution is unlimited

    Automated Data for DevSecOps Programs

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    Excerpt from the Proceedings of the Nineteenth Annual Acquisition Research SymposiumAutomation in DevSecOps (DSO) transforms the practice of building, deploying, and managing software intensive programs. Although this automation supports continuous delivery and rapid builds, the persistent manual collection of information delays (by weeks) the release of program status metrics and the decisions they are intended to inform. Emerging DSO metrics (e.g., deployment rates, lead times) provide insight into how software development is progressing but fall short of replacing program control metrics for assessing progress (e.g., burn rates against spend targets, integration capability tar-get dates, and schedule for the minimum viable capability release). By instrumenting the (potentially in-teracting) DSO pipelines and supporting environments, the continuous measurement of status, identifica-tion of emerging risks, and probabilistic projections are possible and practical. In this paper, we discuss our research on the information modeling, measurement, metrics, and indicators necessary to establish a continuous program control capability that can keep pace with DSO management needs. We discuss the importance of interactive visualization dashboards for addressing program information needs. We also identify and address the gaps and barriers in the current state of the practice. Finally, we recommend future research needs based on our initial findings.Approved for public release; distribution is unlimited

    Improvements in X-Ray Spectrometry for Planetary Surface Exploration

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    Recent innovations in X-ray instrumentation have enabled a new generation of planetary XRS instruments exhibiting performance matching terr estrial laboratory results

    Ammonium recycling supports toxic Planktothrix blooms in Sandusky Bay, Lake Erie: Evidence from stable isotope and metatranscriptome data

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    Sandusky Bay, Lake Erie, receives high nutrient loadings (nitrogen and phosphorus) from the Sandusky River, which drains an agricultural watershed. Eutrophication and cyanobacterial harmful algal blooms (cyanoHABs) persist throughout summer. Planktothrix agardhii is the dominant bloom-forming species and the main producer of microcystins in Sandusky Bay. Non-N2 fixing cyanobacteria, such as Planktothrix and Microcystis, thrive on chemically reduced forms of nitrogen, such as ammonium (NH4+) and urea. Ammonium regeneration and potential uptake rates and total microbial community demand for NH4+ were quantified in Sandusky Bay. Potential NH4+ uptake rates in the light increased from June to August at all stations. Dark uptake rates also increased seasonally and, by the end of August, were on par with light uptake rates. Regeneration rates followed a similar pattern and were significantly higher in August than June. Ammonium uptake kinetics during a Planktothrix-dominated bloom in Sandusky Bay and a Microcystis-dominated bloom in Maumee Bay were also compared. The highest half saturation constant (Km) in Sandusky Bay was measured in June and decreased throughout the season. In contrast, Km values in Maumee Bay were lowest at the beginning of summer and increased in October. A significant increase in Vmax in Sandusky Bay was observed between July and the end of August, reflective of intense competition for depleted NH4+. Metatranscriptome results from Sandusky Bay show a shift from cyanophycin synthetase (luxury NH4+ uptake; cphA1) expression in early summer to cyanophycinase (intracellular N mobilization; cphB/cphA2) expression in August, supporting the interpretation that the microbial community is nitrogen-starved in late summer. Combined, our results show that, in late summer, when nitrogen concentrations are low, cyanoHABs in Sandusky Bay rely on regenerated NH4+ to support growth and toxin production. Increased dark NH4+ uptake late in summer suggests an important heterotrophic contribution to NH4+ depletion in the phycosphere. Kinetic experiments in the two bays suggest a competitive advantage for Planktothrix over Microcystis in Sandusky Bay due to its higher affinity for NH4+ at low concentrations

    Crystal structure of an HD-GYP domain cyclic-di-GMP phosphodiesterase reveals an enzyme with a novel trinuclear catalytic iron centre

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    Bis-(3′,5′) cyclic di-guanylate (c-di-GMP) is a key bacterial second messenger that is implicated in the regulation of many crucial processes that include biofilm formation, motility and virulence. Cellular levels of c-di-GMP are controlled through synthesis by GGDEF domain diguanylate cyclases and degradation by two classes of phosphodiesterase with EAL or HD-GYP domains. Here, we have determined the structure of an enzymatically active HD-GYP domain protein from Persephonella marina (PmGH) alone, in complex with substrate (c-di-GMP) and final reaction product (GMP). The structures reveal a novel trinuclear iron binding site, which is implicated in catalysis and identify residues involved in recognition of c-di-GMP. This structure completes the picture of all domains involved in c-di-GMP metabolism and reveals that the HD-GYP family splits into two distinct subgroups containing bi- and trinuclear metal centres.</p
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