180 research outputs found

    The design of a sampling mill to treat a south east Missouri lead ore

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    The purpose of the work that was undertaken in preparing this thesis was to provide plans and specifications for a sampling mill to be erected by the St. Louis Smelting and Refining Co. at their plant near St. Francois, Mo... It was intended at the outset to design the plant completely and to provide full working drawings and specifications for all parts of the mill. On account of the lack of time, however, it has been found necessary to somewhat reduce the amount of work. As a result only general plans and specifications with a few of the more important details are contained in the finished thesis --Thesis Subject, pages 1-2

    Quantifying Similarity in Reliability Surfaces Using the Probability of Agreement

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    When separate populations exhibit similar reliability as a function of multiple explanatory variables, combining them into a single population is tempting. This can simplify future predictions and reduce uncertainty associated with estimation. However, combining these populations may introduce bias if the underlying relationships are in fact different. The probability of agreement formally and intuitively quantifies the similarity of estimated reliability surfaces across a two-factor input space. An example from the reliability literature demonstrates the utility of the approach when deciding whether to combine two populations or to keep them as distinct. New graphical summaries provide strategies for visualizing the results

    Senior Recital

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    REALISTIC DETECTABILITY OF CLOSE INTERSTELLAR COMETS

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    During the planet formation process, billions of comets are created and ejected into interstellar space. The detection and characterization of such interstellar comets (ICs) (also known as extra-solar planetesimals or extra-solar comets) would give us in situ information about the efficiency and properties of planet formation throughout the galaxy. However, no ICs have ever been detected, despite the fact that their hyperbolic orbits would make them readily identifiable as unrelated to the solar system. Moro-Martin et al. have made a detailed and reasonable estimate of the properties of the IC population. We extend their estimates of detectability with a numerical model that allows us to consider "close" ICs, e.g., those that come within the orbit of Jupiter. We include several constraints on a "detectable" object that allow for realistic estimates of the frequency of detections expected from the Large Synoptic Survey Telescope (LSST) and other surveys. The influence of several of the assumed model parameters on the frequency of detections is explored in detail. Based on the expectation from Moro-Martin et al., we expect that LSST will detect 0.001-10 ICs during its nominal 10 year lifetime, with most of the uncertainty from the unknown number density of small (nuclei of similar to 0.1-1 km) ICs. Both asteroid and comet cases are considered, where the latter includes various empirical prescriptions of brightening. Using simulated LSST-like astrometric data, we study the problem of orbit determination for these bodies, finding that LSST could identify their orbits as hyperbolic and determine an ephemeris sufficiently accurate for follow-up in about 4-7 days. We give the hyperbolic orbital parameters of the most detectable ICs. Taking the results into consideration, we give recommendations to future searches for ICs.Peer reviewe

    Worms and the Treatment of Inflammatory Bowel Disease: Are Molecules the Answer?

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    The lack of exposure to helminth infections, as a result of improved living standards and medical conditions, may have contributed to the increased incidence of IBD in the developed world. Epidemiological, experimental, and clinical data sustain the idea that helminths could provide protection against IBD. Studies investigating the underlying mechanisms by which helminths might induce such protection have revealed the importance of regulatory pathways, for example, regulatory T-cells. Further investigation on how helminths influence both innate and adaptive immune reactions will shed more light on the complex pathways used by helminths to regulate the hosts immune system. Although therapy with living helminths appears to be effective in several immunological diseases, the disadvantages of a treatment based on living parasites are explicit. Therefore, the identification and characterization of helminth-derived immunomodulatory molecules that contribute to the protective effect could lead to new therapeutic approaches in IBD and other immune diseases

    Mental disorder and the outcome of HIV/AIDS in low-income and middle-income countries: a systematic review.

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    OBJECTIVES: To conduct a systematic review of the literature to examine the interrelationship between mental health and treatment outcomes in low-income and middle-income settings; to update the work of Collins et al. (2006). DESIGN: Systematic review of peer-reviewed articles that examined one of the following: the effects of mental disorders (including cognitive impairment) upon engagement with treatment and/or adherence; their influence upon HIV-related clinical outcomes; and the impact of interventions for mental disorder. METHODS: Articles about mental health and HIV/AIDS were included if they were published after 2005 and addressed one of the areas of interest described above. Systematic methods were used for searching, screening, and data extraction. Studies employing quantitative measures of exposures and outcomes wherein all participants had a diagnosis of HIV/AIDS were included. RESULTS: This review found ample and moderately consistent evidence that adverse mental health and alcohol consumption are associated with reduced adherence. Variation in measurement and the relative paucity of work meant that interpretation of studies examining engagement with care and other clinical outcomes was difficult. Evidence on the efficacy and effectiveness of mental health interventions in low-income and middle-income settings was very limited. CONCLUSION: This review suggests that psychosocial factors, namely, depression and alcohol may have adverse effects upon HIV-related outcomes. However, further large, high-quality studies examining outcomes other than adherence are needed. There is also an urgent need for randomized controlled trials of interventions for mental disorder and a need to investigate their impact upon HIV-related outcomes

    Genetic and Non-genetic Predictors of LINE-1 Methylation in Leukocyte DNA.

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    Background: Altered DNA methylation has been associated with various diseases. Objective: We evaluated the association between levels of methylation in leukocyte DNA at long interspersed nuclear element 1 (LINE-1) and genetic and non-genetic characteristics of 892 control participants from the Spanish Bladder Cancer/EPICURO study. Methods: We determined LINE-1 methylation levels by pyrosequencing. Individual data included demographics, smoking status, nutrient intake, toenail concentrations of 12 trace elements, xenobiotic metabolism gene variants, and 515 polymorphisms among 24 genes in the one-carbon metabolism pathway. To assess the association between LINE-1 methylation levels (percentage of methylated cytosines) and potential determinants, we estimated beta coefficients (βs) by robust linear regression. Results: Women had lower levels of LINE-1 methylation than men (β = –0.7, p = 0.02). Persons who smoked blond tobacco showed lower methylation than nonsmokers (β = –0.7, p = 0.03). Arsenic toenail concentration was inversely associated with LINE-1 methylation (β = –3.6, p = 0.003). By contrast, iron (β = 0.002, p = 0.009) and nickel (β = 0.02, p = 0.004) were positively associated with LINE-1 methylation. Single nucleotide polymorphisms (SNPs) in DNMT3A (rs7581217-per allele, β = 0.3, p = 0.002), TCN2 (rs9606756-GG, β = 1.9, p = 0.008; rs4820887-AA, β = 4.0, p = 4.8 × 10–7; rs9621049-TT, β = 4.2, p = 4.7 × 10–9), AS3MT (rs7085104-GG, β = 0.7, p = 0.001), SLC19A1 (rs914238, TC vs. TT: β = 0.5 and CC vs. TT: β = –0.3, global p = 0.0007) and MTHFS (rs1380642, CT vs. CC: β = 0.3 and TT vs. CC; β = –0.8, global p = 0.05) were associated with LINE-1 methylation. Conclusions: We identified several characteristics, environmental factors, and common genetic variants that predicted DNA methylation among study participants.This work was partially supported by the Association for International Cancer Research (AICR; grant 09-0780, and a doctoral scholarship awarded to S.M.T.); Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III, MINECO, Spain (grants 00/0745, PI051436, PI061614, PI09-02102, and G03/174); Red Temática de Investigación Cooperativa en Cáncer (grant RD06/0020-RTICC); the U.S. National Institutes of Health (grant RO1-CA089715); a postdoctoral fellowship awarded to A.F.S.A. from the Fundación Científica de la AECC; Fundació Marató TV3; and The Johns Hopkins University Vredenburg Scholarship awarded to A.L.C
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