854 research outputs found

    Analysis of organic pollutants in sediments and blue crab (Callinectes sapidus) tissues : final report to Virginia State Water Control Board

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    The Elizabeth River is a highly industrialized waterway that divides the cities of Norfolk and Portsmouth at its confluence with the lower Chesapeake Bay. It is home to the largest Naval base on the East Coast, numerous ship repair facilities, bulk and containerized cargo facilities, industrial and urban activities and wood creosoting (preserving) operations (all except one have been abandoned). This degree of industrialization has resulted in the pollution of the river, with high concentrations of polynuclear aromatic hydrocarbons (PAH, Bieri et al., 1986). A major contributor to the pollution problem has been the wood processing industry which, due to industrial accidents and spillage, allowed creosote to enter the river

    Synthesis, screening, and sequencing of cysteine-rich one-bead one-compound peptide libraries.

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    Cysteine-rich peptides are valued as tags for biarsenical fluorophores and as environmentally important reagents for binding toxic heavy metals. Due to the inherent difficulties created by cysteine, the power of one-bead one-compound (OBOC) libraries has never been applied to the discovery of short cysteine-rich peptides. We have developed the first method for the synthesis, screening, and sequencing of cysteine-rich OBOC peptide libraries. First, we synthesized a heavily biased cysteine-rich OBOC library, incorporating 50% cysteine at each position (Ac-X8-KM-TentaGel). Then, we developed conditions for cysteine alkylation, cyanogen bromide cleavage, and direct MS/MS sequencing of that library at the single bead level. The sequencing efficiency of this library was comparable to a traditional cysteine-free library. To validate screening of cysteine-rich OBOC libraries, we reacted a library with the biarsenical FlAsH and identified beads bearing the known biarsenical-binding motif (CCXXCC). These results enable OBOC libraries to be used in high-throughput discovery of cysteine-rich peptides for protein tagging, environmental remediation of metal contaminants, or cysteine-rich pharmaceuticals

    Current collection by high voltage anodes in near ionospheric conditions

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    The authors experimentally identified three distinct regimes with large differences in current collection in the presence of neutrals and weak magnetic fields. In magnetic field/anode voltage space the three regions are separated by very sharp transition boundaries. The authors performed a series of laboratory experiments to study the dependence of the region boundaries on several parameters, such as the ambient neutral density, plasma density, magnetic field strength, applied anode voltage, voltage pulsewidth, chamber material, chamber size and anode radius. The three observed regimes are: classical magnetic field limited collection; stable medium current toroidal discharge; and large scale, high current space glow discharge. There is as much as several orders of magnitude of difference in the amount of collected current upon any boundary crossing, particularly if one enters the space glow regime. They measured some of the properties of the plasma generated by the breakdown that is present in regimes II and III in the vicinity of the anode including the sheath modified electrostatic potential, I-V characteristics at high voltage as well as the local plasma density

    The Removal of Artificially Generated Polarization in SHARP Maps

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    We characterize the problem of artificial polarization for the Submillimeter High Angular Resolution Polarimeter (SHARP) through the use of simulated data and observations made at the Caltech Submillimeter Observatory (CSO). These erroneous, artificial polarization signals are introduced into the data through misalignments in the bolometer sub-arrays plus pointing drifts present during the data-taking procedure. An algorithm is outlined here to address this problem and correct for it, provided that one can measure the degree of the sub-array misalignments and telescope pointing drifts. Tests involving simulated sources of Gaussian intensity profile indicate that the level of introduced artificial polarization is highly dependent upon the angular size of the source. Despite this, the correction algorithm is effective at removing up to 60% of the artificial polarization during these tests. The analysis of Jupiter data taken in January 2006 and February 2007 indicates a mean polarization of 1.44%+/-0.04% and 0.95%+/-0.09%, respectively. The application of the correction algorithm yields mean reductions in the polarization of approximately 0.15% and 0.03% for the 2006 and 2007 data sets, respectively.Comment: 19 pages, 7 figure

    Correlation Between Electron Capture Negative Chemical Ionization Mass Spectrometric Fragmentation and Calculated Internal Energies for Polychlorinated Biphenyls

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    Correlations between molecular structure and fragmentation observed in electron capture negative chemical ionization mass spectra (moderator gas = methane) of 49 selected tetrachlorinated, pentachlorinated, and hexachlorinated biphenyls have been investigated by using molecular modeling. The semiempirical general molecular orbital program MOPAC was used to calculate molecular properties for biphenyl and the 209 polychlorinated biphenyls. The mass spectrometric ionization and fragmentation processes were found to be linked to the number of chlorine atoms present on the biphenyl, and to the number of those chlorine atoms in the ortho (2, 2\u27, 6, and 6\u27) positions. The intensity of molecular ions increased with the number of chlorine atoms present, but this was counteracted by enhanced fragmentation as the number of ortho position chlorine atoms increased. The molecular parameters that were most closely linked with the number of ortho chlorine atoms were the twist angle between the phenyl rings and the energy of the lowest unoccupied molecular orbital (LUMO). It is suggested that fragmentation occurs when the energy of the ionizing electron exceeds the energy difference between the LUMO and LUMO + 1 orbitals

    Effective Behavior Change Techniques in Asthma Self-Care Interventions: Systematic Review and Meta-Regression

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    This article may not exactly replicate the final version published in the APA journal. It is not the copy of record.APA Journals®Objectives: The purpose of this study is to update previous systematic reviews of interventions targeting asthma self-care in adults with asthma, and to use meta-regression to examine the association between the use of specific behavior change techniques and intervention effectiveness. Methods: Electronic bibliographies were searched systematically to identify randomized controlled trials of interventions targeting asthma self-care. Intervention content was coded using a published taxonomy of behavior change techniques. For trials with a low-to-moderate risk of bias, study outcomes were pooled using random effects meta-analysis. Associations between intervention content and effect size were explored using meta-regression. Results: Meta-analysis of 38 trials (7883 patients) showed that interventions targeting asthma self-care reduced symptoms (standardized mean difference [SMD] = -0.38 [-0.52, -0.24]) and unscheduled health care use (odds ratio [OR] = 0.71 [0.56 to 0.90]) and increased adherence to preventive medication (OR = 2.55 [2.11 to 3.10]). meta-regression analyses found that "active involvement of participants" was associated with a reduction in unscheduled health care use (OR = 0.50 vs. 0.79). Inclusion of "stress management" techniques was associated with an increase in asthma symptoms (SMD = 0.01 vs. -0.44). Existing recommendations about the "optimal" content of asthma self-care interventions were tested but were not supported by the data. Conclusions: Interventions targeting asthma self-care are effective. Active involvement of participants is associated with increased intervention effectiveness, but the use of stress management techniques may be counterproductive. Taxonomy-based systematic reviews using meta-regression have potential for identifying techniques associated with increased effectiveness in behavioral interventions. (PsycINFO Database Record (c) 2013 APA, all rights reserved)

    Assessing Social Agency Functions: A Model

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    The assessment of general agency functions is the focus of this manuscript. Initially inventories that may be utilized in the assessment of the relevance and quality of services provided are reviewed. Next, cost benefit analysis is addressed in terms of helping social workers estimate the cost of services provided. The manuscript concludes with a discussion of the issues involved in general agency assessment
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