2,917 research outputs found
Structural dynamics payload loads estimates: User guide
This User Guide with an overview of an integration scheme to determine the response of a launch vehicle with multiple payloads. Chapter II discusses the software package associated with the integration scheme together with several sample problems. A short cut version of the integration technique is also discussed. The Guide concludes with a list of references and the listings of the subroutines
B spectroscopy using all-to-all propagators
We measure the ground and excited states for B mesons in the static limit
using maximally variance reduced estimators for light quark propagators.
Because of the large number of propagators we are able to measure accurately
also orbitally excited P, D and F states. We also present some results for
Lambda_b.Comment: 3 pages, 3 figures. Talk presented at Lattice '97 by J. Peis
Impact of wild-type and genetically modified Pseudomonas fluorescens on soil enzyme activities and microbial population structure in the rhizosphere of pea
The definitive version is available at www.blackwell-synergy.com. Copyright Blackwell Publishing DOI : 10.1046/j.1365-294x.1998.00367.xThe aim of this work was to determine the impact of wild type along with functionally and non-functionally modified Pseudomonas fluorescens strains in the rhizosphere. The wild type F113 strain carried a gene encoding the production of the antibiotic 2,4 diacetylphloroglucinol (DAPG) useful in plant disease control, and was marked with a lacZY gene cassette. The first modified strain was a functional modification of strain F113 with repressed production of DAPG, creating the DAPG negative strain F113 G22. The second paired comparison was a non-functional modification of wild type (unmarked) strain SBW25, constructed to carry marker genes only, creating strain SBW25 EeZY-6KX. Significant perturbations were found in the indigenous bacterial population structure, with the F113, (DAPG+) strain causing a shift towards slower growing colonies (K strategists) compared with the non-antibiotic producing derivative (F113 G22) and the SBW25 strains. The DAPG+ strain also significantly reduced, in comparison with the other inocula, the total Pseudomonas populations but did not affect the total microbial populations. The survival of F113 and F113 G22 were an order of magnitude lower than the SBW 25 strains. The DAPG+ strain caused a significant decrease in the shoot to root ratio in comparison to the control and other inoculants, indicating plant stress. F113 increased soil alkaline phosphatase, phosphodiesterase and aryl sulphatase activities compared to the other inocula, which themselves reduced the same enzyme activities compared to the control. In contrast to this, the -glucosidase, -galactosidase and N-acetyl glucosaminidase activities decreased with the inoculation of the DAPG+ strain. These results indicate that soil enzymes are sensitive to the impact of GMM inoculation.Peer reviewe
Evaluation of pollutant removal efficiency of a bioretention basin and implications for stormwater management in tropical cities
Non-point source pollution is a prevalent problem throughout the world. Bioretention basins have been deployed worldwide to treat stormwater runoff and alleviate eutrophication in downstream water resources. However, basin performance in the tropics is poorly understood. Given the distinctly different rainfall-runoff characteristics of tropical climates, whether basins that are built according to temperate design guidelines are effective is questionable. There have been no field studies based on continuous, high-resolution, long-term monitoring in the tropics. In this study, 96 storms were monitored in the first bioretention basin in Singapore. Of these, flow measurements were made during 80 events and samples were collected and analyzed for 15 water quality parameters (including nitrogen and phosphorus species, total suspended solids, and chemical oxygen demand) during six events. The mean removal rates were 25%, 46%, and 53% for total nitrogen, total phosphorus, and total suspended solids respectively. Results show that a lack of storage capacity and resulting high overflow reduce pollutant removal efficiency for high-rainfall-depth events. The transition from efficient to non-efficient removal occurs at a rainfall depth between 10 and 30 mm. Low EMC (event mean concentration) and weak first flush as a result of frequent and intense rainfall in the tropics also contribute to low removal rate. The results suggest a need to revise bioretention basin design guidelines for the tropics to be based on WQV or WQD (water quality volume or depth) instead of ARI (average recurrence interval). A larger basin volume (WQD between 10 to 30 mm) is recommended.Singapore. National Research Foundation (Singapore-MIT Alliance for Research and Technology. Center for Environmental Sensing and Modeling
Serum antibodies in first-degree relatives of patients with IBD: A marker of disease susceptibility? A follow-up pilot-study after 7 years
Introduction: Various disease-specific serum antibodies were described in patients with inflammatory bowel disease and their yet healthy first-degree relatives. In the latter, serum antibodies are commonly regarded as potential markers of disease susceptibility. The present long-term follow-up study evaluated the fate of antibody-positive first-degree relatives. Patients and Methods: 25 patients with Crohn's disease, 19 patients with ulcerative colitis and 102 first-degree relatives in whom presence of ASCA, pANCA, pancreatic- and goblet-cell antibodies had been assessed were enrolled. The number of incident cases with inflammatory bowel disease was compared between antibody-positive and antibody-negative first-degree relatives 7 years after storage of serum samples. Results: 34 of 102 (33%) first-degree relatives were positive for at least one of the studied serum antibodies. In the group of first-degree relatives, one case of Crohn's disease and one case of ulcerative colitis were diagnosed during the follow-up period. However, both relatives did not display any of the investigated serum antibodies (p = 1). Discussion: The findings of our pilot study argue against a role of serum antibodies as a marker of disease susceptibility in first-degree relatives of patients with inflammatory bowel disease. However, these data have to await confirmation in larger ideally prospective multicenter studies before definite conclusions can be drawn
Serum antibodies in first-degree relatives of patients with IBD: A marker of disease susceptibility? A follow-up pilot-study after 7 years
Introduction: Various disease-specific serum antibodies were described in patients with inflammatory bowel disease and their yet healthy first-degree relatives. In the latter, serum antibodies are commonly regarded as potential markers of disease susceptibility. The present long-term follow-up study evaluated the fate of antibody-positive first-degree relatives. Patients and Methods: 25 patients with Crohn's disease, 19 patients with ulcerative colitis and 102 first-degree relatives in whom presence of ASCA, pANCA, pancreatic- and goblet-cell antibodies had been assessed were enrolled. The number of incident cases with inflammatory bowel disease was compared between antibody-positive and antibody-negative first-degree relatives 7 years after storage of serum samples. Results: 34 of 102 (33%) first-degree relatives were positive for at least one of the studied serum antibodies. In the group of first-degree relatives, one case of Crohn's disease and one case of ulcerative colitis were diagnosed during the follow-up period. However, both relatives did not display any of the investigated serum antibodies (p = 1). Discussion: The findings of our pilot study argue against a role of serum antibodies as a marker of disease susceptibility in first-degree relatives of patients with inflammatory bowel disease. However, these data have to await confirmation in larger ideally prospective multicenter studies before definite conclusions can be drawn
Gravitational form factors of the proton from lattice QCD
The gravitational form factors (GFFs) of a hadron encode fundamental aspects
of its structure, including its shape and size as defined from e.g., its energy
density. This work presents a determination of the flavor decomposition of the
GFFs of the proton from lattice QCD, in the kinematic region . The decomposition into up-, down-, strange-quark, and gluon
contributions provides first-principles constraints on the role of each
constituent in generating key proton structure observables, such as its
mechanical radius, mass radius, and -term.Comment: Additional comparisons added to Figures 2 and 4. 8 pages, 4 figures,
1 table in the main text plus 11 pages, 8 figures, 2 tables in the
supplementary materia
Industrial Security Clearance and Individual Freedom
Industrial Security Clearance and Individual Freedo
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