130 research outputs found

    Particle dispersion models and drag coefficients for particles in turbulent flows

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    Some of the concepts underlying particle dispersion due to turbulence are reviewed. The traditional approaches to particle dispersion in homogeneous, stationary turbulent fields are addressed, and recent work on particle dispersion in large scale turbulent structures is reviewed. The state of knowledge of particle drag coefficients in turbulent gas-particle flows is also reviewed

    Reactivity-Dependent PCR: Direct, Solution-Phase in Vitro Selection for Bond Formation

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    In vitro selection is a key component of efforts to discover functional nucleic acids and small molecules from libraries of DNA, RNA, and DNA-encoded small molecules. Such selections have been widely used to evolve RNA and DNA catalysts and, more recently, to discover new reactions from DNA-encoded libraries of potential substrates. While effective, current strategies for selections of bond-forming and bond-cleaving reactivity are generally indirect, require the synthesis of biotin-linked substrates, and involve multiple solution-phase and solid-phase manipulations. In this work we report the successful development and validation of reactivity-dependent PCR (RDPCR), a new method that more directly links bond formation or bond cleavage with the amplification of desired sequences and that obviates the need for solid-phase capture, washing, and elution steps. We show that RDPCR can be used to select for bond formation in the context of reaction discovery and for bond cleavage in the context of protease activity profiling.Chemistry and Chemical Biolog

    The rank reversal problem in multi-criteria decision making : a literature review

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    Despite the importance of multicriteria decision-making (MCDM) techniques for constructing effective decision models, there are many criticisms due to the occurrence of a problem called rank reversal. Nevertheless, there is a lack of a systematic literature review on this important subject which involves different methods. This study reviews the pertinent literature on rank reversal, based on 130 related articles published from 1980 to 2015 in international journals, which were gathered and analyzed according to the following perspectives: multicriteria technique, year and journal in which the papers were published, co-authorship network, rank reversal types, and research goal. Thus our survey provides recommendations for future research, besides useful information and knowledge regarding rank reversal in the MCDM field

    Colorectal cancer prevention for low-income, sociodemographically-diverse adults in public housing: baseline findings of a randomized controlled trial

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    Background: This paper presents the study design, intervention components, and baseline data from Open Doors to Health, a study designed to address social contextual factors in colorectal cancer (CRC) prevention for low-income, racial/ethnic minority populations. Methods: A cluster randomized design with 12 housing sites as the primary sampling units was used: 6 sites were assigned to a Peer-led plus Screening Access (PL) condition, and 6 were assigned to Screening Access only (SCR) condition. Study-related outcomes were CRC screening, physical activity (measured as mean steps/day), and multivitamin use. Results: At baseline (unweighted sample size = 1554), two-thirds self-reported that they were current with screening recommendations for CRC (corrected for medical records validation, prevalence was 52%), with half having received a colonoscopy (54%); 96% had health insurance. Mean steps per day was 5648 (se mean = 224), and on average 28% of the sample reported regular multivitamin use. Residents reported high levels of social support [mean = 4.40 (se = .03)] and moderately extensive social networks [mean = 2.66 (se = .02)]. Conclusion: Few studies have conducted community-based studies in public housing communities; these data suggest areas for improvement and future opportunities for intervention development and dissemination. Findings from the randomized trial will determine the effectiveness of the intervention on our health-related outcomes as well as inform future avenues of research

    Effects of Wind Speed and Direction on Monthly Fluctuations of Cladosporium Conidia Concentration in the Air

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    This study determined the relationship between airborne concentration of Cladosporium spp. spores and wind speed and direction using real data (local wind measured by weather station) and modelled data (air mass flow computed with the aid of HYbrid Single Particle Lagrangian Trajectory model). Air samples containing fungal conidia were taken at an urban site (Worcester, UK) for a period of five consecutive years using a spore trap of the Hirst design. A threshold of ≥6000 s m−3 (double the clinical value) was applied in order to select high spore concentration days, when airborne transport of conidia at a regional scale was more likely to occur. Collected data were then examined using geospatial and statistical tools, including circular statistics. Obtained results showed that the greatest numbers of spore concentrations were detected in July and August, when C. herbarum, C. cladosporioides and C. macrocarpum sporulate. The circular correlation test was found to be more sensitive than Spearman’s rank test. The dominance of either local wind or the air mass on Cladosporium spore distributions varied between examined months. Source areas of this pathogen had an origin within the UK territory. Very high daily mean concentrations of Cladosporium spores were observed when daily mean local wind speed was vs ≤ 2.5 m s−1 indicating warm days with a light breeze
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