965 research outputs found

    Central Limit Theorems for some Set Partition Statistics

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    We prove the conjectured limiting normality for the number of crossings of a uniformly chosen set partition of [n] = {1,2,...,n}. The arguments use a novel stochastic representation and are also used to prove central limit theorems for the dimension index and the number of levels

    Unofficial answers to the Uniform certified public accountants examination, May 1948 to November 1950

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    https://egrove.olemiss.edu/aicpa_exam/1111/thumbnail.jp

    Closed expressions for averages of set partition statistics

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    In studying the enumerative theory of super characters' of the group of upper triangular matrices over a finite field we found that the moments (mean, variance and higher moments) of novel statistics on set partitions have simple closed expressions as linear combinations of shifted bell numbers. It is shown here that families of other statistics have similar moments. The coefficients in the linear combinations are polynomials in nn. This allows exact enumeration of the moments for small nn to determine exact formulae for all nn

    A pilot randomised controlled trial of metacognitive therapy for prolonged grief

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    Objectives: Prolonged grief disorder is associated with significant distress and impairment and thus efforts to improve treatments are essential. The present pilot study tested the efficacy and feasibility of group Metacognitive Grief Therapy (MCGT) designed specifically for prolonged grief symptomatology to reduce the psychological distress and impaired function resulting from bereavement. Design/participants: Twenty-two bereaved adult participants with prolonged grief symptomatology were randomised to a wait-list control (n=10) or an intervention condition (n=12) with a 3-month and 6-month follow-up. The wait-list control group was offered treatment after the post-test assessment. Intervention: Participants attended six group MCGT sessions that ran for 2 hours per week. Outcome measures: A primary outcome measure of prolonged grief symptomatology and secondary outcome measures of depression, anxiety, rumination, metacognitive beliefs and quality of life were taken pretreatment and post-treatment for both groups and at the 3-month and 6-month follow-up for the intervention group. A Generalised Linear Mixed Model was used to assess treatment efficacy. Results: Post-treatment intent-to-treat analyses showed MCGT reduced prolonged grief symptomatology (Cohen's d=1.7), depression (d=1.3), anxiety (d=0.8), stress (d=1.0), rumination (d=0.9) and increased quality of life (d=0.6), and these effects were maintained at the 3-month and 6-month follow-ups. No prepost between-group differences were found in metacognitive beliefs. However, a large significant effect was identified at the 3-month and 6-month follow-ups (d=1.0). Conclusion: The results show promise for the utility of group MCGT for reducing psychological distress and promoting quality of life. Additionally, the results underscore the need for a full randomised controlled trial of group MCGT, which may be an important addition to the treatment armamentarium available to support people with prolonged grief

    Supersymmetric Electroweak Parity Nonconservation in Top Quark Pair Production at the Fermilab Tevatron

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    We evaluate the supersymmetric (SUSY) electroweak corrections to the effect of parity nonconservation in qqĖ‰ā†’ttĖ‰q {\bar q} \to t {\bar t} production at the Fermilab Tevatron predicted by the Minimal Supersymmetric Model (MSSM). We find that the parity nonconserving asymmetry from the SUSY electroweak and SUSY Yukawa loop corrections predicted by the minimal supergravity (mSUGRA) model and the MSSM models with scenarios motivated by current data is about one percent. It will be challenging to observe such a small asymmetry at the Tevatron with 10 fb^{-1} of luminosity. It could however be observable if both the top- and bottom-squarks are light and tanā”Ī²\tan \beta is smaller than 1, though theses parameters are not favored by mSUGRA.Comment: revised version, some new numerical results adde

    A 3-dimensional in vitro model of epithelioid granulomas induced by high aspect ratio nanomaterials

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    <p>Abstract</p> <p>Background</p> <p>The most common causes of granulomatous inflammation are persistent pathogens and poorly-degradable irritating materials. A characteristic pathological reaction to intratracheal instillation, pharyngeal aspiration, or inhalation of carbon nanotubes is formation of epithelioid granulomas accompanied by interstitial fibrosis in the lungs. In the mesothelium, a similar response is induced by high aspect ratio nanomaterials, including asbestos fibers, following intraperitoneal injection. This asbestos-like behaviour of some engineered nanomaterials is a concern for their potential adverse health effects in the lungs and mesothelium. We hypothesize that high aspect ratio nanomaterials will induce epithelioid granulomas in nonadherent macrophages in 3D cultures.</p> <p>Results</p> <p>Carbon black particles (Printex 90) and crocidolite asbestos fibers were used as well-characterized reference materials and compared with three commercial samples of multiwalled carbon nanotubes (MWCNTs). Doses were identified in 2D and 3D cultures in order to minimize acute toxicity and to reflect realistic occupational exposures in humans and in previous inhalation studies in rodents. Under serum-free conditions, exposure of nonadherent primary murine bone marrow-derived macrophages to 0.5 Ī¼g/ml (0.38 Ī¼g/cm<sup>2</sup>) of crocidolite asbestos fibers or MWCNTs, but not carbon black, induced macrophage differentiation into epithelioid cells and formation of stable aggregates with the characteristic morphology of granulomas. Formation of multinucleated giant cells was also induced by asbestos fibers or MWCNTs in this 3D <it>in vitro </it>model. After 7-14 days, macrophages exposed to high aspect ratio nanomaterials co-expressed proinflammatory (M1) as well as profibrotic (M2) phenotypic markers.</p> <p>Conclusions</p> <p>Induction of epithelioid granulomas appears to correlate with high aspect ratio and complex 3D structure of carbon nanotubes, not with their iron content or surface area. This model offers a time- and cost-effective platform to evaluate the potential of engineered high aspect ratio nanomaterials, including carbon nanotubes, nanofibers, nanorods and metallic nanowires, to induce granulomas following inhalation.</p

    Integrase-deficient lentiviral vectors mediate efficient gene transfer to human vascular smooth muscle cells with minimal genotoxic risk

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    We have previously shown that injury-induced neointima formation was rescued by adenoviral-Nogo-B gene delivery. Integrase-competent lentiviral vectors (ICLV) are efficient at gene delivery to vascular cells but present a risk of insertional mutagenesis. Conversely, integrase-deficient lentiviral vectors (IDLV) offer additional benefits through reduced mutagenesis risk, but this has not been evaluated in the context of vascular gene transfer. Here, we have investigated the performance and genetic safety of both counterparts in primary human vascular smooth muscle cells (VSMC) and compared gene transfer efficiency and assessed the genotoxic potential of ICLVs and IDLVs based on their integration frequency and insertional profile in the human genome. Expression of enhanced green fluorescent protein (eGFP) mediated by IDLVs (IDLV-eGFP) demonstrated efficient transgene expression in VSMCs. IDLV gene transfer of Nogo-B mediated efficient overexpression of Nogo-B in VSMCs, leading to phenotypic effects on VSMC migration and proliferation, similar to its ICLV version and unlike its eGFP control and uninfected VSMCs. Large-scale integration site analyses in VSMCs indicated that IDLV-mediated gene transfer gave rise to a very low frequency of genomic integration compared to ICLVs, revealing a close-to-random genomic distribution in VSMCs. This study demonstrates for the first time the potential of IDLVs for safe and efficient vascular gene transfer
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