969 research outputs found

    Direct measurement of carbon-14 in carbon dioxide by liquid scintillation counting

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    Liquid scintillation counting technique is applied to the direct measurement of carbon-14 in carbon dioxide. This method has high counting efficiency and eliminates many of the basic problems encountered with previous techniques. The technique can be used to achieve a percent substitution reaction and is of interest as an analytical technique

    Recent development in organic scintillators

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    Discussion on recent developments of organic scintillators includes studies of organic compounds that form glass-like masses which scintillate and are stable at room temperature, correlations between molecular structure of organic scintillators and self-quenching, recently developed fast scintillators, and applications of liquid-scintillation counters

    Low Rank Vector Bundles on the Grassmannian G(1,4)

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    Here we define the concept of LL-regularity for coherent sheaves on the Grassmannian G(1,4) as a generalization of Castelnuovo-Mumford regularity on Pn{\bf{P}^n}. In this setting we prove analogs of some classical properties. We use our notion of LL-regularity in order to prove a splitting criterion for rank 2 vector bundles with only a finite number of vanishing conditions. In the second part we give the classification of rank 2 and rank 3 vector bundles without "inner" cohomology (i.e. H^i_*(E)=H^i(E\otimes\Q)=0 for any i=2,3,4i=2,3,4) on G(1,4) by studying the associated monads.Comment: 11 pages, no figure

    Candida Transmission and Sexual Behaviors as Risks for a Repeat Episode of Candida Vulvovaginitis

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    Objective: To assess associations between female and male factors and the risk of recurring Candida vulvovaginitis. Methods: A prospective cohort study of 148 women with Candida vulvovaginitis and 78 of their male sexual partners was conducted at two primary care practices in the Ann Arbor, Michigan, area. Results: Thirty-three of 148 women developed at least one further episode of Candida albicans vulvovaginitis within 1 year of follow-up. Cultures of Candida species from various sites of the woman (tongue, feces, vulva, and vagina) and from her partner (tongue, feces, urine, and semen) did not predict recurrences. Female factors associated with recurrence included recent masturbating with saliva (hazard ratio 2.66 [95% CI 1.17-6.06]) or cunnilingus (hazard ratio 2.94 [95% CI 1.12-7.68]) and ingestion of two or more servings of bread per day (p ≤ 0.05). Male factors associated with recurrences in the woman included history of the male masturbating with saliva in the previous month (hazard ratio 3.68 [95% CI 1.24-10.87]) and lower age at first intercourse (hazard ratio 0.83 [95% CI 0.71-0.96]). Conclusions: Sexual behaviors, rather than the presence of Candida species at various body locations of the male partner, are associated with recurrences of C. albicans vulvovaginitis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63382/1/154099903322643901.pd

    Neurology

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    Contains research objectives and reports on six research projects.National Science Foundation (Grant G-16526)National Institutes of Health (Grant MH-04737-03)U.S. Public Health Service (B-3055-3)U.S. Public Health Service (B-3090-3)U.S. Public Health Service (MH-06175-01A1)Office of Naval Research (Nonr-1841(70))Air Force (AFOSR 155-63)Army Chemical Corps (DA- 18-108-405-CML-942

    Neurology

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    Contains reports on six research projects.United States Public Health Service (B-3055-4, B-3090-4, MH-06175-02)United States Navy, Office of Naval Research (Contract Nonr-1841(70))United States Air Force (AF49(638)-1313), administered by the Electronic Systems Laboratory, M. I. T

    Insulin Glargine in the Intensive Care Unit: A Model-Based Clinical Trial Design

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    Online 4 Oct 2012Introduction: Current succesful AGC (Accurate Glycemic Control) protocols require extra clinical effort and are impractical in less acute wards where patients are still susceptible to stress-induced hyperglycemia. Long-acting insulin Glargine has the potential to be used in a low effort controller. However, potential variability in efficacy and length of action, prevent direct in-hospital use in an AGC framework for less acute wards. Method: Clinically validated virtual trials based on data from stable ICU patients from the SPRINT cohort who would be transferred to such an approach are used to develop a 24-hour AGC protocol robust to different Glargine potencies (1.0x, 1.5x and 2.0x regular insulin) and initial dose sizes (dose = total insulin over prior 12, 18 and 24 hours). Glycemic control in this period is provided only by varying nutritional inputs. Performance is assessed as %BG in the 4.0-8.0mmol/L band and safety by %BG<4.0mmol/L. Results: The final protocol consisted of Glargine bolus size equal to insulin over the previous 18 hours. Compared to SPRINT there was a 6.9% - 9.5% absolute decrease in mild hypoglycemia (%BG<4.0mmol/L) and up to a 6.2% increase in %BG between 4.0 and 8.0mmol/L. When the efficacy is known (1.5x assumed) there were reductions of: 27% BG measurements, 59% insulin boluses, 67% nutrition changes, and 6.3% absolute in mild hypoglycemia. Conclusion: A robust 24-48 clinical trial has been designed to safely investigate the efficacy and kinetics of Glargine as a first step towards developing a Glargine-based protocol for less acute wards. Ensuring robustness to variability in Glargine efficacy significantly affects the performance and safety that can be obtained

    Characterization of breast tissue using energy-dispersive X-ray diffraction computed tomography

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    Abstract A method for sample characterization using energy-dispersive X-ray diffraction computed tomography (EDXRDCT) is presented. The procedures for extracting diffraction patterns from the data and the corrections applied are discussed. The procedures were applied to the characterization of breast tissue samples, 6 mm in diameter. Comparison with histological sections of the samples confirmed the possibility of grouping the patterns into five families, corresponding to adipose tissue, fibrosis, poorly differentiated cancer, well differentiated cancer, and benign tumour

    PLASMAPHERESIS IN RAYNAUD'S DISEASE

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22629/1/0000179.pd

    The repulsive lattice gas, the independent-set polynomial, and the Lov\'asz local lemma

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    We elucidate the close connection between the repulsive lattice gas in equilibrium statistical mechanics and the Lovasz local lemma in probabilistic combinatorics. We show that the conclusion of the Lovasz local lemma holds for dependency graph G and probabilities {p_x} if and only if the independent-set polynomial for G is nonvanishing in the polydisc of radii {p_x}. Furthermore, we show that the usual proof of the Lovasz local lemma -- which provides a sufficient condition for this to occur -- corresponds to a simple inductive argument for the nonvanishing of the independent-set polynomial in a polydisc, which was discovered implicitly by Shearer and explicitly by Dobrushin. We also present some refinements and extensions of both arguments, including a generalization of the Lovasz local lemma that allows for "soft" dependencies. In addition, we prove some general properties of the partition function of a repulsive lattice gas, most of which are consequences of the alternating-sign property for the Mayer coefficients. We conclude with a brief discussion of the repulsive lattice gas on countably infinite graphs.Comment: LaTex2e, 97 pages. Version 2 makes slight changes to improve clarity. To be published in J. Stat. Phy
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