2,163 research outputs found

    The influence of the Chi_b(3P) state on the decay cascade of bottomium in PbPb collisions at LHC energies

    Full text link
    We investigate the decay cascade of the Upsilon(nS) meson including the newly found Chi_b(3P) state in pp and PbPb collisions at LHC energies. The main goal is to quantitatively determine the additional suppression of the Upsilon(nS) states in PbPb collisions relative to pp at LHC energies of sqrt(s_NN) = 2.76 TeV when the Chi_b(3P) state is included together with the Upsilon(nS) and Chi_b(1P,2P) states. It is found that the suppression of Upsilon(1S) in PbPb collisions relative to pp is increased by at most 7% through the inclusion of Chi_b(3P), whereas the suppression factors for the Upsilon(2S) and Upsilon(3S) states do not change significantly.Comment: 4 pages, 2 figure

    GREMEX update (Goddard research engineering management exercise)

    Get PDF
    Management simulation techniques offer training in management problems. Exercise was developed to provide experience in research and development project decision making from management rather than technological perspective. Program and documentation have been revised innumerable times in past. Described report is revised version as it exists to date

    GREMEX-A new management training concept

    Get PDF
    Goddard Research Engineering Management Exercise provides experience in R&D project decision making from a management rather than technological view. The participant directs a hypothetical project presented in the management simulation technique. He uses old or new methods without concern for rewards or penalties existing in real life

    Tradeoff between extractable mechanical work, accessible entanglement, and ability to act as a reference system, under arbitrary superselection rules

    Full text link
    Superselection rules (SSRs) limit the mechanical and quantum processing resources represented by quantum states. However SSRs can be violated using reference systems to break the underlying symmetry. We show that there is a duality between the ability of a system to do mechanical work and to act as a reference system. Further, for a bipartite system in a globally symmetric pure state, we find a triality between the system's ability to do local mechanical work, its ability to do ``logical work'' due to its accessible entanglement, and its ability to act as a shared reference system.Comment: 5 pages, no figures. Extended resubmitted version. Slightly modified title. Transferred to PR

    Available nitrogen and phosphorus and the biochemical cycle in the Atlantic off New England

    Get PDF
    The importance of ammonia as a sourc:e of available nitrogen for phytoplanktonic populations off New England has been evaluated for August and January 1962. During August, when only trace amounts of nitrate persist in the photic layer, ammonia appears to be the major source of available nitrogen. Therefore, meaningful estimates of the relative amounts of nitrogen and phosphorus being assimilated at such times require consideration of the nitrogen occurring as ammonia...

    Thermal stability and aggregation of sulfolobus solfataricus b-glycosidase are dependent upon the N-e-methylation of specific lysyl residues: critical role of in vivo post-translational modifications.

    Get PDF
    Methylation in vivo is a post-translational modification observed in several organisms belonging to eucarya, bacteria, and archaea. Although important implications of this modification have been demonstrated in several eucaryotes, its biological role in hyperthermophilic archaea is far from being understood. The aim of this work is to clarify some effects of methylation on the properties of β-glycosidase from Sulfolobus solfataricus, by a structural comparison between the native, methylated protein and its unmethylated counterpart, recombinantly expressed in Escherichia coli. Analysis by Fourier transform infrared spectroscopy indicated similar secondary structure contents for the two forms of the protein. However, the study of temperature perturbation by Fourier transform infrared spectroscopy and turbidimetry evidenced denaturation and aggregation events more pronounced in recombinant than in native β-glycosidase. Red Nile fluorescence analysis revealed significant differences of surface hydrophobicity between the two forms of the protein. Unlike the native enzyme, which dissociated into SDS-resistant dimers upon exposure to the detergent, the recombinant enzyme partially dissociated into monomers. By electrospray mapping, the methylation sites of the native protein were identified. A computational analysis of β-glycosidase three-dimensional structure and comparisons with other proteins from S. solfataricus revealed analogies in the localization of methylation sites in terms of secondary structural elements and overall topology. These observations suggest a role for the methylation of lysyl residues, located in selected domains, in the thermal stabilization of β-glycosidase from S. solfataricu

    Industrial Problems Encountered in the Eddy Current Inspection of Steel

    Get PDF
    It is anticipated, that through exposing some of the problems encountered in industrial applications of eddy current technology, technical assistance may be generated through the theoretical community. The specific problem examined involves the development, storage\u27and utilization of calibration masters. Although the use of probes versus coils greatly reduces the number of calibration masters in that probes are not sensitive to overall geometry and mass variations, the eddy current response is influenced by near probe geometry variations. At present, an empirically derived algorithm is relied upon to characterize this phenomenon although it is hoped that an appropriate theoretical model will be developed. In addition to geometry, the non-linear permeability present in ferromagnetics, and the microstructural and compositional variations greatly increase the complexity of constructing such a model

    The annual cycle of phosphorus and nitrogen in New England coastal waters

    Get PDF
    Distributions of phosphorus and nitrogen in New England coastal waters at various times of year are described. In surface waters the nitrate-nitrogen content is sometimes completely exhausted, even though small concentrations (0.2-0.5µg-at/l) of phosphorus are always available. The ratio of concentrations by atoms, N:P, varies in surface waters from maximum values of about 10: 1 to values approaching zero as the nitrate is exhausted...

    First-line erlotinib and fixed dose-rate gemcitabine for advanced pancreatic cancer

    Get PDF
    AIM: To investigate activity, toxicity, and prognostic factors for survival of erlotinib and fixed dose-rate gemcitabine (FDR-Gem) in advanced pancreatic cancer. METHODS: We designed a single-arm prospective, multicentre, open-label phase II study to evaluate the combination of erlotinib (100 mg/d, orally) and weekly FDR-Gem (1000 mg/m2, infused at 10 mg/m2per minute) in a population of previously untreated patients with locally advanced, inoperable, or metastatic pancreatic cancer. Primary endpoint was the rate of progression-free survival at 6 mo (PFS-6); secondary endpoints were overall response rate (ORR), response duration, tolerability, overall survival (OS), and clinical benefit. Treatment was not considered to be of further interest if the PFS-6 was < 20% (p0 = 20%), while a PFS-6 > 40% would be of considerable interest (p1 = 40%); with a 5% rejection error (α = 5%) and a power of 80%, 35 fully evaluable patients with metastatic disease were required to be enrolled in order to complete the study. Analysis of prognostic factors for survival was also carried out. RESULTS: From May 2007 to September 2009, 46 patients were enrolled (male/female: 25/21; median age: 64 years; median baseline carbohydrate antigen 19-9 (CA 19-9): 897 U/mL; locally advanced/metastatic disease: 5/41). PFS-6 and median PFS were 30.4% and 14 wk (95%CI: 10-19), respectively; 1-year and median OS were 20.2% and 26 wk (95%CI: 8-43). Five patients achieved an objective response (ORR: 10.9%, 95%CI: 1.9-19.9); disease control rate was 56.5% (95%CI: 42.2-70.8); clinical benefit rate was 43.5% (95%CI: 29.1-57.8). CA 19-9 serum levels were decreased by > 25% as compared to baseline in 14/23 evaluable patients (63.6%). Treatment was well-tolerated, with skin rash being the most powerful predictor of both longer PFS (P < 0.0001) and OS (P = 0.01) at multivariate analysis (median OS for patients with or without rash: 42 wk vs 15 wk, respectively, Log-rank P = 0.03). Additional predictors of better outcome were: CA 19-9 reduction, female sex (for PFS), and good performance status (for OS). CONCLUSION: Primary study endpoint was not met. However, skin rash strongly predicted erlotinib efficacy, suggesting that a pharmacodynamic-based strategy for patient selection deserves further investigation
    • …
    corecore