1,464 research outputs found

    Production of Secondary Organic Aerosol During Aging of Biomass Burning Smoke From Fresh Fuels and Its Relationship to VOC Precursors

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    After smoke from burning biomass is emitted into the atmosphere, chemical and physical processes change the composition and amount of organic aerosol present in the aged, diluted plume. During the fourth Fire Lab at Missoula Experiment, we performed smog-chamber experiments to investigate formation of secondary organic aerosol (SOA) and multiphase oxidation of primary organic aerosol (POA). We simulated atmospheric aging of diluted smoke from a variety of biomass fuels while measuring particle composition using high-resolution aerosol mass spectrometry. We quantified SOA formation using a tracer ion for low-volatility POA as a reference standard (akin to a naturally occurring internal standard). These smoke aging experiments revealed variable organic aerosol (OA) enhancements, even for smoke from similar fuels and aging mechanisms. This variable OA enhancement correlated well with measured differences in the amounts of emitted volatile organic compounds (VOCs) that could subsequently be oxidized to form SOA. For some aging experiments, we were able to predict the SOA production to within a factor of 2 using a fuel-specific VOC emission inventory that was scaled by burn-specific toluene measurements. For fires of coniferous fuels that were dominated by needle burning, volatile biogenic compounds were the dominant precursor class. For wiregrass fires, furans were the dominant SOA precursors. We used a POA tracer ion to calculate the amount of mass lost due to gas-phase oxidation and subsequent volatilization of semivolatile POA. Less than 5% of the POA mass was lost via multiphase oxidation-driven evaporation during up to 2 hr of equivalent atmospheric oxidation

    Boundedness, compactness and Schatten-class membership of weighted composition operators

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    The boundedness and compactness of weighted composition operators on the Hardy space H2{\mathcal H}^2 of the unit disc is analysed. Particular reference is made to the case when the self-map of the disc is an inner function. Schatten-class membership is also considered; as a result, stronger forms of the two main results of a recent paper of Gunatillake are derived. Finally, weighted composition operators on weighted Bergman spaces A2α(D)\mathcal{A}^2 \alpha(\mathbb{D}) are considered, and the results of Harper and Smith, linking their properties to those of Carleson embeddings, are extended to this situation.Comment: 12 page

    Patient/Family Education for Newly Diagnosed Pediatric Oncology Patients

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    There is a paucity of data to support evidence-based practices in the provision of patient/family education in the context of a new childhood cancer diagnosis. Since the majority of children with cancer are treated on pediatric oncology clinical trials, lack of effective patient/family education has the potential to negatively affect both patient and clinical trial outcomes. The Children’s Oncology Group Nursing Discipline convened an interprofessional expert panel from within and beyond pediatric oncology to review available and emerging evidence and develop expert consensus recommendations regarding harmonization of patient/family education practices for newly diagnosed pediatric oncology patients across institutions. Five broad principles, with associated recommendations, were identified by the panel, including recognition that (1) in pediatric oncology, patient/family education is family-centered; (2) a diagnosis of childhood cancer is overwhelming and the family needs time to process the diagnosis and develop a plan for managing ongoing life demands before they can successfully learn to care for the child; (3) patient/family education should be an interprofessional endeavor with 3 key areas of focus: (a) diagnosis/treatment, (b) psychosocial coping, and (c) care of the child; (4) patient/family education should occur across the continuum of care; and (5) a supportive environment is necessary to optimize learning. Dissemination and implementation of these recommendations will set the stage for future studies that aim to develop evidence to inform best practices, and ultimately to establish the standard of care for effective patient/family education in pediatric oncology

    An Electroweak Weizsacker-Williams Method

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    The Weizsacker-Williams method is a semiclassical approximation scheme used to analyze a wide variety of electromagnetic interactions. It can greatly simplify calculations that would otherwise be impractical or impossible to carry out using the standard route of the Feynman rules. With a few reasonable assumptions, the scope of the method was generalized so as to accommodate weak, as well as the usual electromagnetic, interactions. The results are shown to be in excellent agreement, in the high energy limit of interest, with other methods, and the generalized scheme is shown to still work in regimes of analysis where those methods break down.Comment: PhD thesis, 239 pages, 36 figures, LaTe

    Production of Secondary Organic Aerosol During Aging of Biomass Burning Smoke From Fresh Fuels and Its Relationship to VOC Precursors

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    After smoke from burning biomass is emitted into the atmosphere, chemical and physical processes change the composition and amount of organic aerosol present in the aged, diluted plume. During the fourth Fire Lab at Missoula Experiment, we performed smog-chamber experiments to investigate formation of secondary organic aerosol (SOA) and multiphase oxidation of primary organic aerosol (POA). We simulated atmospheric aging of diluted smoke from a variety of biomass fuels while measuring particle composition using high-resolution aerosol mass spectrometry. We quantified SOA formation using a tracer ion for low-volatility POA as a reference standard (akin to a naturally occurring internal standard). These smoke aging experiments revealed variable organic aerosol (OA) enhancements, even for smoke from similar fuels and aging mechanisms. This variable OA enhancement correlated well with measured differences in the amounts of emitted volatile organic compounds (VOCs) that could subsequently be oxidized to form SOA. For some aging experiments, we were able to predict the SOA production to within a factor of 2 using a fuel-specific VOC emission inventory that was scaled by burn-specific toluene measurements. For fires of coniferous fuels that were dominated by needle burning, volatile biogenic compounds were the dominant precursor class. For wiregrass fires, furans were the dominant SOA precursors. We used a POA tracer ion to calculate the amount of mass lost due to gas-phase oxidation and subsequent volatilization of semivolatile POA. Less than 5% of the POA mass was lost via multiphase oxidation-driven evaporation during up to 2 hr of equivalent atmospheric oxidation

    Barriers encountered during enrollment in an internet-mediated randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Online technology is a promising resource for conducting clinical research. While the internet may improve a study's reach, as well as the efficiency of data collection, it may also introduce a number of challenges for participants and investigators. The objective of this research was to determine the challenges that potential participants faced during the enrollment phase of a randomized controlled intervention trial of Stepping Up to Health, an internet-mediated walking program that utilized a multi-step online enrollment process.</p> <p>Methods</p> <p>We conducted a quantitative content analysis of 623 help tickets logged in a participant management database during the enrollment phase of a clinical trial investigating the effect of an automated internet-mediated walking intervention. Qualitative coding was performed by two trained coders, and 10% of the sample was coded by both coders to determine inter-coder reliability. Quantitative analyses included standard descriptive statistics on ticket characteristics and theme frequency, and a Poisson regression analysis identified characteristics of potential participants who reported more frequent problems during enrollment.</p> <p>Results</p> <p>In total, 880 potential participants visited the study website and 80% completed the enrollment screening. Of the potential participants who visited the study website, 38% had help tickets logged in the participant management database. The total number of help tickets associated with individual potential participants ranged from 0 to 7 (M = .71). Overall, 46% of help tickets were initiated by email and 54% were initiated by phone. The most common help ticket theme was issues related to the study process (48%). The next most prominent theme was discussion related to obtaining medical clearance (34%), followed by issues related to pedometers and uploading (31%). Older individuals, women, and those with lower self-rated internet ability were more likely to report problems during the enrollment process.</p> <p>Conclusion</p> <p>Prospective participants in an online clinical trial encountered a number of barriers to enrollment that led them to request help from study staff. Questions about the complex enrollment process itself were common. In a complex multi-step enrollment process, providing personalized feedback to potential participants indicating their status within the enrollment process may be beneficial.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov NCT00729040</p

    Television Watching and Mental Health in the General Population of New York City After September 11

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    The September 11, 2001 terrorist attacks were watched on television by millions. Using data from a telephone survey of New York City residents in January 2002 (N = 2001), we examined the relations between television watching and probable posttraumatic stress disorder (PTSD) after the attacks. Among those who were directly affected by the attacks or had prior traumatic experiences, watching television was associated with probable PTSD. Experiencing a peri-event panic reaction accounted for some of the association between television watching and probable PTSD. Future research directions are suggested for better understanding the mechanisms behind observed associations between television watching and PTSD.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/40284/2/Ahern_Television Watching and Mental Health in_2005.pd

    Maturity Model for Interoperability Potential Measurement

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    Interoperability potential concerns the preparation level of an enterprise to establish an efficient collaboration with possible part- ners. In order to improve their interoperability, enterprises need to know witch level of maturity they have achieved. This article pro- poses a complete maturity model composed by a methodology and a reference set of parameters to measure interoperability potential. In order to clarify the proposal, an example of application in a real case is described.Campos, C.; Chalmeta, R.; Grangel, R.; Poler Escoto, R. (2013). Maturity Model for Interoperability Potential Measurement. Information Systems Management. 30(3):218-234. doi:10.1080/10580530.2013.794630S218234303Alfaro, J. J., Rodriguez-Rodriguez, R., Verdecho, M. J., & Ortiz, A. (2009). Business process interoperability and collaborative performance measurement. International Journal of Computer Integrated Manufacturing, 22(9), 877-889. doi:10.1080/09511920902866112Sabucedo, L. Á., & Rifón, L. A. (2010). Managing Citizen Profiles in the Domain of e-Government: The cPortfolio Project. Information Systems Management, 27(4), 309-319. doi:10.1080/10580530.2010.514181Berre, A.-J., Elvesæter, B., Figay, N., Guglielmina, C., Johnsen, S. G., Karlsen, D., … Lippe, S. (s. f.). The ATHENA Interoperability Framework. Enterprise Interoperability II, 569-580. doi:10.1007/978-1-84628-858-6_62Blanc, S., Ducq, Y., & Vallespir, B. (2007). Evolution management towards interoperable supply chains using performance measurement. Computers in Industry, 58(7), 720-732. doi:10.1016/j.compind.2007.05.011Campos, C., Martí, I., Grangel, R., Mascherpa, A. and Chalmeta, R. A methodological proposal for the development of an interoperability framework.Model Driven Interoperability for Sustainable Information Systems (MDISIS′08) (CAiSE′08). Vol. 340, pp.47–57. CEUR-WS. http://ceur-ws.org/Vol-340/paper04.pdfChalmeta, R., & Grangel, R. (2005). Performance measurement systems for virtual enterprise integration. International Journal of Computer Integrated Manufacturing, 18(1), 73-84. doi:10.1080/0951192042000213164Doumeingts, G. and Chen, D. Basic concepts and approaches to develop interoperability of enterprise applications.PRO-VE,IFIP Conference Proceedings. Edited by: Camarinha-Matos, L. M. and Afsarmanesh, H. Vol. 262, pp.323–330. Norwell, MA: Kluwer.Duque, A., Campos, C., Jimenez-Ruiz, E. and Chalmeta, R. An ontological solution to supprot interoperability in the textile industry.Second IFIP WG 5.8 International Workshop, IWEI 2009. Edited by: Poler, M. V. S. R. Vol. 38, pp.38–51. New York: Springer.Guédria, W., Naudet, Y., & Chen, D. (2008). Interoperability Maturity Models – Survey and Comparison –. Lecture Notes in Computer Science, 273-282. doi:10.1007/978-3-540-88875-8_48Hoving, R. (2007). Information Technology Leadership Challenges — Past, Present, and Future. Information Systems Management, 24(2), 147-153. doi:10.1080/10580530701221049Palomares, N., Campos, C., & Palomero, S. (2010). How to Develop a Questionnaire in Order to Measure Interoperability Levels in Enterprises. Enterprise Interoperability IV, 387-396. doi:10.1007/978-1-84996-257-5_36Walsham, G. (1995). Interpretive case studies in IS research: nature and method. European Journal of Information Systems, 4(2), 74-81. doi:10.1057/ejis.1995.

    Adult Spiny Mice (\u3ci\u3eAcomys\u3c/i\u3e) Exhibit Endogenous Cardiac Recovery in Response to Myocardial Infarction

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    Complex tissue regeneration is extremely rare among adult mammals. An exception, however, is the superior tissue healing of multiple organs in spiny mice (Acomys). While Acomys species exhibit the remarkable ability to heal complex tissue with minimal scarring, little is known about their cardiac structure and response to cardiac injury. In this study, we first examined baseline Acomys cardiac anatomy and function in comparison with commonly used inbred and outbred laboratory Mus strains (C57BL6 and CFW). While our results demonstrated comparable cardiac anatomy and function between Acomys and Mus, Acomys exhibited a higher percentage of cardiomyocytes displaying distinct characteristics. In response to myocardial infarction, all animals experienced a comparable level of initial cardiac damage. However, Acomys demonstrated superior ischemic tolerance and cytoprotection in response to injury as evidenced by cardiac functional stabilization, higher survival rate, and smaller scar size 50 days after injury compared to the inbred and outbred mouse strains. This phenomenon correlated with enhanced endothelial cell proliferation, increased angiogenesis, and medium vessel maturation in the peri-infarct and infarct regions. Overall, these findings demonstrate augmented myocardial preservation in spiny mice post-MI and establish Acomys as a new adult mammalian model for cardiac research
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